iaea-158 report final 03 december 2009 documents... · international atomic energy agency marine...

Report No. IAEA/AL/187

IAEA/MEL/82

World -Wide Intercomparison Exercise On The Determination Of Trace Elements

In IAEA-158 Marine Sediment

M. J. Campbell, S. Azemard and J. Oh

March 2008

International Atomic Energy Agency Marine Environment Laboratories

4 quai Antoine 1er MC 98000 Monaco

Prepared in collaboration with:

UNEP

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CONTENT

1. INTRODUCTION ...............................................................................................5 2. SCOPE OF THE INTERCOMPARISON ...........................................................6 3. DESCRIPTION OF THE MATERIAL ...............................................................7 4. HOMOGENEITY TESTS ...................................................................................9 5. Stability ..............................................................................................................10 6. ANALYSES AND REPORTING......................................................................10 7. EVALUATION OF THE RESULTS ................................................................11

7.1 Data Table Term: .........................................................................................11 7.2 Statistical and technical evaluation..............................................................13 7.3 Certification criteria .....................................................................................14

8. RESULTS AND DISCUSSION........................................................................17 8.1 Overview of the results ................................................................................17

8.1.1. Moisture content ..................................................................................17 8.1.2. Analytical methods ..............................................................................18 8.1.3. Laboratory performances .....................................................................21

8.2 Laboratory performance for selected trace elements ...................................32 8.2.1. Aluminium ...........................................................................................33 8.2.2. Arsenic .................................................................................................34 8.2.3. Cadmium..............................................................................................35 8.2.4. Chromium ............................................................................................36 8.2.5. Copper, Cobalt, Nickel and Zinc .........................................................37 8.2.6. Lead......................................................................................................40 8.2.7. Manganese and Iron .............................................................................41 8.2.8. Mercury................................................................................................43 8.2.9. Strontium and Vanadium: ....................................................................44

9. METHYLMERCURY .......................................................................................46 10. RECOMMENDATIONS...................................................................................50 11. CONCLUSIONS................................................................................................51 12. ACKNOWLEDGEMENTS...............................................................................51 13. REFERENCES ..................................................................................................51 APPENDIX I Data report of the individual laboratory results sorted by element......54 APPENDIX II Graphical presentation of results sorted by element...........................82 APPENDIX III List of participants............................................................................115 APPENDIX IV Reference Sheet for IAEA-158.......................................................124

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LIST OF TABLES Table 1. Within- and between- bottle homogeneity for IAEA-158 ...............................9 Table 2. Method codes for IAEA-158 .........................................................................12 Table 3. Results of intercomparison exercise IAEA-158 marine sediment.................16 Table 4. Frequency of use for different analytical techniques.....................................20 Table 5. Summary of performance by element............................................................24 Table 6. Assessment of laboratories based on z-scores ...............................................25 Table 7. Overall assessment of laboratory performance..............................................30 Table 8. List of laboratories and analytical methods used for methylmercury determinations..............................................................................................................47

LIST OF FIGURES Figure 1. Particle size distribution profile for IAEA-158 ..............................................8 Figure 2: Proportional distribution of analytical techniques used to analyse IAEA-158...................................................................................................18 Figure 3.Aluminium results derived from different methods ......................................33 Figure 4. Total vs Partial reported mean for Aluminium.............................................34 Figure 5: Arsenic results derived from different methods ...........................................35 Figure 6: Cadmium results derived from different methods........................................36 Figure 7: Chromium results derived from different methods ......................................37 Figure 8. Copper results derived from different methods............................................38 Figure 9. Cobalt results derived from different methods.............................................38 Figure 10. Nickel results derived from different methods...........................................39 Figure 11. Zinc results derived from different methods ..............................................39 Figure 12: Lead results derived from different methods .............................................40 Figure 13. Manganese results derived from different methods ...................................42 Figure 14. Iron results derived from different methods...............................................42 Figure 15: Mercury results derived from different methods........................................43 Figure 16. Strontium results derived from different methods......................................45 Figure 17. Vanadium results derived from different methods.....................................45 Figure 18: Plot extracted of the automatic generated report of the BWE Cofino model.....................................................................................................48 Figure 19: Reported means and sample preparation procedure...................................49

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1. INTRODUCTION For nearly thirty years, the Marine Environmental Studies Laboratory (MESL)

of International Atomic Energy Agency-Marine Environment Laboratories (IAEA-MEL) has conducted worldwide laboratory performance studies, also known as intercomparison exercises1, 2. The results have been used to characterise both laboratory performance and the materials themselves with respect to a wide range of organic3, 4 and inorganic constituents, including methylmercury5-8. Thus, test samples can subsequently be used as reference materials (RMs) for organic and inorganic marine pollution studies. This work, a contribution to the IAEA Analytical Quality Control Services (AQCS), has been conducted in collaboration with the UNEP Regional Seas Programme. In the past, such exercises were also carried out in association with the IOC Global Investigation of the Pollution in the Marine Environment (GIPME) programme9.

Quality assurance and quality control (QA/QC) cover a very broad discipline; there are numerous factors and protocols that must be employed to validate data and ensure reliable analytical performance. A good QA/QC programme should include internal performance checks for day-to-day validation10, 11, as well as regular external performance evaluations for an independent assessment of analytical proficiency9, 12. In the first case, a routine method of quality control entails the concurrent processing of a material of known composition that is of similar matrix to the sample, i.e., a reference material, to confirm the accuracy of the analytical process. This should be a continuous and regular process, not only to maximize the confidence in a particular data set, but also to maximize the confidence in an analytical process, and indeed, in how the laboratory routinely operates in the longer term10, 11. An intercomparison exercise, such as this interlaboratory study, serves as such an independent external assessment. Interlaboratory comparisons are not only essential for checking the accuracy of a laboratory’s analytical results, but also serve to stimulate better analytical performance11, 12.

The present interlaboratory study was designed in order to evaluate the measurement performance of participating laboratories for the analysis of trace elements in fish homogenate samples. Following the statistical evaluation obtained results were used to assign a reference value for several trace elements and methyl mercury in the test material and to fulfil the increased demand for marine reference materials characterised for trace elements and methyl mercury (MeHg).

The test material was distributed to 140 laboratories worldwide and the results from 93 laboratories in 41 countries were received by end 2006.

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The data reported by laboratories, together with the technical and statistical evaluations of the results for each element, are given in this report. As statistical and technical criteria to assign the reference value of a number of elements were fulfilled, the sample can now be used as a reference material for quality control in the determination of trace elements and methyl mercury in marine sediment.

The performance of the participant laboratories was assessed through evaluating Z-scores. These results should assist chemists to make appropriate modifications to laboratory analytical procedures in order to improve data quality. All results were treated confidentially and each laboratory was identified with a code number for anonymity.

Further information concerning this report and the IAEA quality assurance programme can be obtained from the Marine Environmental Studies Laboratory, IAEA-MEL, 4 Quai Antoine 1er, MC 98000, Monaco or the web site: http://www-naweb.iaea.org/naml/. 2. SCOPE OF THE INTERCOMPARISON

In February 2006, 308 letters of invitation were sent out to laboratories that had expressed a wish to participate, or previously participated, in an IAEA intercomparison exercise on the determination of trace elements in marine samples, soliciting interest in this exercise. Positive responses were received from 140 laboratories in 59 IAEA Member States and samples were duly dispatched to them. Each participating laboratory received one sample of the marine sediment material, designated IAEA-158, accompanied by an information sheet and a reporting form. Using the procedures routinely applied in their laboratories, participants were requested to determine as many elements as possible from the following 18 elements: Al, As, Cd, Co, Cr, Cu, Fe, Hg (total and methylmercury), Li, Mn, Ni, Pb, Sb, Se, Sn, Sr, V and Zn. The IAEA was also interested to receive results for any other elements that participating laboratories were willing to provide to enhance the characterisation of the matrix.

The deadline for returning the results was initially set at September 2006, but was later extended to the end of November 2006 due to delays in dispatching the samples from Monaco.

In total 93 laboratories from 41 countries participated to this intercomparison exercise and reported results for up to 51 elements (including methylmercury).

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The distribution of participants belonging to countries included in the UNEP Regional Seas Programmes was as follows: Number of laboratories Number of countries Mediterranean Action Plan 30 14 Kuwait Action Plan 4 4 West and Central Africa Action Plan 1 1 Caribbean Action Plan 1 2 East Asian Seas Action Plan 3 2 South-East Pacific Action Plan 6 2 Eastern African Action Plan 2 2 South Asian Seas Action Plan 4 2 Black Sea Environmental Programme 14 5 South-West Atlantic 4 1 3. DESCRIPTION OF THE MATERIAL

In November 2004, a large quantity of marine sediment was collected from Kilbrannan Sound, south east of the island of Arran, in the Clyde River estuary, Scotland, UK. The material was collected and supplied to the IAEA through collaboration with the QUASIMEME Laboratory Performance Studies Programme. The material was freeze dried by QUASIMEME and sent to IAEA MEL for further processing and bottling. The dried material was hand sieved (315 µm) by MESL staff. The sieving cut-off value chosen was a compromise value selected to ensure that the physical properties of the material should be sufficiently uniform whilst retaining sufficient material to make an adequate number of units. The particle size distribution profile of the bottled material was measured using a MALVERN Mastersizer Micro v2.12 instrument. This device uses the diffraction of laser light to determine the range of particle sizes in the sample. The particle size distribution profile for IAEA-158 is presented in Figure 1. Approximately 70% of particles had sizes below 100 µm. In the context of a reference material, it is important that the substance is finely divided and physically as “homogeneous” as possible, such that sub-samples are as representative as possible and physical processes such as digestion (and moisture determination) will be reproducible.

Aliquots of about 25 g were packed into glass bottles with polyethylene caps and sealed in plastic bags. Approximately five hundred units of the material were prepared, providing adequate supplies to be used as a reference material at the

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conclusion of the interlaboratory study. The homogeneity of this material for trace elements was tested using a standard protocol and found to be satisfactory for the purposes of this intercomparison exercise (at or above an intake mass of 200 mg). Metal concentrations are expected to match the range normally found in the marine environment in this region.

Particle Diameter (µm.)

Volume (%)

0

10

010 20 30 40 50 60 70 80 90 100

0.1 1.0 10.0 100.0 1000.0

Figure 1. Particle size distribution profile for IAEA-158

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4. HOMOGENEITY TESTS

A homogeneity test was conducted after bottling the sample material. The between- bottle homogeneity was tested by the determination of the concentration of some typical elements (Cd, Cu, Fe, Hg, Mn, Pb and Zn) in sample aliquots of 0.25 g taken from nine bottles, which were set aside at regular intervals during the whole period of bottling. The within- bottle homogeneity was assessed through 6 determinations of the contents of one bottle. The uncertainty of the analytical methods was assessed for each element by 5 replicate measurements from one standard solution or on one digest solution.

For the determination of trace elements, the samples were mineralized with HNO3, HF and boric acid using a microwave digestion system prior to dilution to volume with appropriate amounts of deionised water. The final determination was performed by F-AAS for Cu, Mn, Fe and Zn, and by ZGF-AAS for Cd and Pb. The total mercury (Hg) was determined by Solid-AAS (AMA 254, Altec). The coefficients of variation (CV) obtained for the studied elements are presented in Table 1.

Table 1. Within- and between- bottle homogeneity for IAEA-158

Element Within-bottle 1

CV (%) Between-bottle 2

CV (%) Method 3 CV (%)

Cd 4.6 5.4 2.9 Cu 5.8 8.6 4.2 Fe 2.9 2.0 4.1 Pb 6.1 4.3 4.6 Mn 2.4 2.1 3.7 Hg 10.5 13.8 1.5 Zn 4.2 3.4 3.2

1 6 replicate determinations on the content of 1 bottle. 2 Single determinations on the content of 6 bottles. 3 5 replicates of a digested solution and reference material (for Hg) CV = Coefficient of variation.

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An F-test was performed for the different metals and revealed no significant differences between the within- and between- bottle variances at a significance level of 0.05, indicating that the heterogeneity observed was relatively consistent. However, for Hg it appears that the variance is clearly much greater than the analytical variability of the method. It was observed that the relatively high variation was due to “high” values that would be considered as outlier if tested statistically. The experiment for Hg was repeated 3 times, using different bottles and different weights and similar results were achieved. It was hypothesised that very fine particulates in the material may be associated with the high Hg values. The fact that analysis of additional units of IAEA-158 returned the same result suggests that the probability to obtain extreme values is the same for all bottles. It was concluded that this artefact should not be a problem for the intercomparison exercise.

5. STABILITY

Previous IAEA trace element reference material (biological and sediment) have been continuously tested for stability. Sets of bottles are stored under different conditions (+20°C, -20°C and +60°C) and are regularly analysed for trace elements. No significant changes were found until now. IAEA 158 is expected to have similar stability. The stability of this CRM will continue to be monitored and customers will be notified if any significant irregularity occurs prior to the expiry date, which as been set at January 2019. 6. ANALYSES AND REPORTING

The participants in this worldwide intercomparison exercise were requested to determine the trace metal amount content in marine sediment sample IAEA-158 using the techniques routinely employed in their laboratories. They were requested to make at least three, but preferably six, independent replicate determinations for each element and to record all results on the reporting form. They were also asked to provide both a summary of the quality control procedures routinely employed (if any) for trace metals analysis within their laboratory and the results of the reference materials analysed concurrently with the test material. Other information requested included the drying procedure and a short description of the analytical method used, comprising the pre-treatment or separation methods (i.e. mineralization/digestion procedure) and the way results were calculated.

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All results were to be reported on a dry-weight basis and the residual moisture content of the sediment sample had to be indicated. The analyte concentrations were to be reported as net values (i.e. after blank correction etc.), leaving as many significant figures as justified by the precision of the method used. For each element, the participants were requested to report the average weight of the sample taken for analysis, the concentration of each independent replicate determination, the arithmetic mean, standard deviation (sn-1) of the replicate determinations and detection limit of the method. 7. EVALUATION OF THE RESULTS

7.1 Data Table Term: All the results reported by the participating laboratories are presented in

Appendix I (results are displayed as received i.e. with all significant numbers reported). The main terms used in those tables are defined below.

Lab code: Each participant was identified by a unique code number known only to themselves and the IAEA.

Number of replicates: Number of independent replicate determinations for a given element performed by a laboratory using the same analytical procedure in the sample material.

Laboratory mean: Arithmetic mean () computed for each element from all individual results supplied by a laboratory. Results given as below the detection limit (DL) are reported with the symbol "<" if the detection limit was reported. Results reported less than DL without reporting DL or reported as Not Detected are not in the tables.

Standard deviation (Std. Dev.): The standard deviation (sn-1) of the laboratory mean for each laboratory.

RSD (Relative Standard Deviation): Calculated in percent as: 100(%) ×=

XiSiRSD

Where Si is the standard deviation and Xi is the mean.

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Instrumental Technique, Digestion and Acid Code: Pre-treatment and instrumental techniques are coded as follow: Pre-treatment (digestion) techniques: 0: No pre-treatment (i.e. non destructive technique such as NAA or XRF) 1: Microwave digestion 2: Hot plate (closed vessel) 3: Hot plate (open vessel) 4: Fusion ?: No information provided Acids used: 1: Digestion mixture contains HF 2: Digestion mixture does not contain HF

Table 2. Method codes for IAEA-158 Method Code Instrumental Technique A1 AAS, flame (F-AAS) A2 Unused coding for this study A3 AAS, electrothermal, + Zeeman background correction (ZGF-AAS) A4 AAS, electrothermal, + Deuterium background correction (GF-AAS) A5 Unused coding for this study A6 AAS, electrothermal, background correction not specified (GF-AAS) A7 AAS, cold vapour (SnCl2) (CV-AAS) A8 AAS, hydride generation (NaBH4) (Hydr.-AAS) A9 AAS, electrothermal, solid analyser E0 Emission spectrometry, unspecified E1 Emission spectrometry, inductively coupled plasma (ICP-AES) E2 Emission spectrometry, inductively coupled plasma (ICP-AES), Hydride

Generation F1 Atomic fluorescence spectrophotometry, cold vapour (SnCl2), (CV-AFS) M1 Mass spectrometry, inductively coupled plasma (ICP-MS) N0 Neutron Activation Analysis (NAA), unspecified N1 Unused coding for this study N2 NAA, instrumental (INAA) P Polarography T Titration X1 X-ray Fluorescence (XRF)

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Quality Control: The identity of the Certified Reference Materials or other quality control material used by the laboratories to assure the quality of the data produced for the analysis of IAEA-158. Don’t fill if no quality control results reported.

7.2 Statistical and technical evaluation In this intercomparison exercise, the overall mean concentration assigned for

each element was calculated using the Cofino model13. The primary advantage of this model is that all data are used, but extreme values (i.e. outliers) are ascribed such a small weighting factor that they essentially eliminate themselves. The Cofino model is quite flexible and can be used to evaluate data arising from different probability distributions. Since all data submitted by the participants were used to calculate the results, the Cofino model obviates the need to screen the data sets for outliers. Every value is taken into consideration to calculate the assigned result. The mean concentration values determined by the Cofino model are based on modal distributions; therefore each data set will have multiple means if more than one mode is found. The return mean will be the one with the highest probability. In evaluating the data, it is therefore necessary to examine the modes while considering the probable limitations of a particular digestion procedure, likelihood of contamination or poor recovery of a given element, etc. A common example of a bimodal distribution for which a preference (based on analytical judgement) would be given to a particular mode would be in the case of certain silicon-bound elements in sediment: there will normally be 2 discrete distributions corresponding to laboratories that did or did not use HF during sample dissolution. The dissolution effect for some elements (Al, Cr, Fe, Mn, Sr and V) will be discussed in detail Section 8.2. But as a conclusion the 1st mode mean was found to be the best estimate of the true value for almost all elements, and so was used to generate reference values of IAEA 158 (Table 3). Exceptions are done for Al and V, as the Cofino model was rerun without data produced with partial digestion (i.e. no HF) to generate reference values.

For MeHg a specific evaluation of data is described in Section 9, and the final value is estimated with a different version of Cofino model14. The main difference being that the uncertainty of individual means is estimated by the model instead of using the reported standard deviation of participants.

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In addition to the compiled data sets given in Appendix I, the distributions of laboratory means for selected elements are illustrated graphically in Appendix II. The laboratory means are plotted in ascending concentration on the y-axis with their corresponding laboratory code noted along the x-axis (S-plots). Error bars represent the standard deviation of the mean reported by each laboratory. The horizontal lines correspond to the higher and lower variability limits of the assigned concentration, (i.e., first mode mean ± 1 standard deviation). The X represents data received with no QC, while results reported with erroneous QC (i.e. reference material result being bias by more than 25%) are marked in pink if bias low and in blue if bias high. The non numerical values (less than) are presented in green. These graphs are presented for all elements with at least 3 reported values.

7.3 Certification criteria The data for many of the elements are sufficiently well grouped to assign

concentrations, thereby enabling the marine sediment sample to be used as a reference material.

Criteria used for assigning reference and information values are indicated bellow. It should be noted that some changes were made compare to previous exercise, especially regarding the maximum allowed standard deviation.

1. For an assigned mean concentration value the analytical uncertainty does

not exceed the following in house limits Concentration range Maximum RSD% >100 mg kg-1 10% 10 - 100 mg kg-1 15% 0.1 - 10 mg kg-1 20% <0.1 mg kg-1 30% 2. The overall mean is based on data obtained by at least two different

methods.* 3. The overall mean is calculated on the basis of at least the following

number of laboratory means: 5 (a); 3(b)* * The percentage of dataset included in the model mean is known. Criteria 2 and 3 apply to dataset included in the model.

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On the basis of these criteria, two classes (categories) of certification are defined:

Recommended Values: Criteria 1, 2 and 3(a) are fulfilled Information Values: Criteria 1 and 3(b) are fulfilled

The classification of the data is shown in Table 3. were: Mean is the mean calculated using the Cofino Model Std. Dev is the standard deviation calculated using the Cofino model RSD is the relative standard deviation (see 7.1) N is the total number of reported datasets * MeHg is reported as inorganic Hg

Following the above criteria Reference values were assigned for 26 elements and Information values were established for a further 15 elements, but the characterisation criteria were not fulfilled (excessive RSD) for 2 elements (Nd and Se). The results for these two elements are indicated in Table 4, but were not included in the Reference Sheet for this marine sediment reference material. It should be noted that Hg (and MeHg) fulfilled criteria to be reported as Recommended values, but as describe in section 4 the homogeneity of the material (for Hg) is not sufficient for a reference material, so it was decided to classify Hg as Information value. Effectively the study showed that there is non negligible probability to get an outlier result. It was not possible to run the homogeneity test for MeHg but as a precaution and until it can be shown that the probable “high particulates” contains only inorganic Hg it was decided to classified MeHg as Information as well.

The results reported as information values should be used with caution. In some cases (Ba, Br, Li, Mg, Mo, Tb, Ti and Yb) low number of results was included in the calculation of the model mean to assign a recommended value. For Hf, Lu, Sc, Ta, Th, the data included for the calculation derived from only one analytical method.

In the case of B, Be, Nb, S, Si, Tl, Y and Zr data was received from less than three laboratories, so they were not considered further in this report. However, for the sake of completeness, these values are reported in Appendix I. The reference sheet prepared for IAEA-158 is presented in Appendix IV.

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Table 3. Results of intercomparison exercise IAEA-158 marine sediment (in mg kg-1) Analyte Unit Mean Std Dev. RSD (%) N % of N in

the Model Class Ag mg kg-1 0.180 0.033 18 10 44 Recommended Al g kg-1 51.8 3.4 7 17 37 Recommended As mg kg-1 11.5 1.2 11 50 42 Recommended Ba mg kg-1 1028 46 4 9 36 Information Br mg kg-1 224 15 7 7 54 Information Ca g kg-1 64.9 5.8 9 11 39 Recommended Cd mg kg-1 0.372 0.039 11 66 37 Recommended Ce mg kg-1 61.1 5.4 9 9 54 Recommended Co mg kg-1 9.2 1.1 12 51 32 Recommended Cr mg kg-1 74.4 5.8 8 71 31 Recommended Cs mg kg-1 3.73 0.34 9 8 63 Recommended Cu mg kg-1 48.3 4.2 9 83 52 Recommended Eu mg kg-1 1.079 0.061 6 7 63 Recommended Fe g kg-1 26.3 1.4 5 68 34 Recommended Hf mg kg-1 6.23 0.40 6 7 62 Information Hg mg kg-1 0.132 0.014 10 54 43 Information K g kg-1 20.0 1.6 8 13 50 Recommended La mg kg-1 30.2 2.2 7 10 62 Recommended Li mg kg-1 32.5 3.7 11 12 29 Information Lu mg kg-1 0.306 0.030 10 5 83 Information MeHg* µg kg-1

1.41 0.40 28 12 76 Information Mg g kg-1 10.39 0.96 9 15 22 Information Mn mg kg-1 356 24 7 71 31 Recommended Mo mg kg-1 4.87 0.80 16 6 68 Information Na g kg-1 23.8 1.0 4 14 49 Recommended Nd mg kg-1 26.8 4.2 16 6 47 - Ni mg kg-1 30.3 2.9 10 63 34 Recommended Pb mg kg-1 39.6 4.7 12 75 38 Recommended Rb mg kg-1 82 10 12 13 47 Recommended Sb mg kg-1 1.34 0.18 13 15 51 Recommended Sc mg kg-1 8.32 0.39 5 10 50 Information Se mg kg-1 0.93 0.26 28 16 34 - Sm mg kg-1 4.94 0.32 7 9 62 Recommended Sn mg kg-1 5.84 0.82 14 12 35 Recommended Sr mg kg-1 473 25 5 26 29 Recommended Ta mg kg-1 0.97 0.12 12 6 75 Information Tb mg kg-1 0.630 0.097 15 6 62 Information Th mg kg-1 8.89 0.58 7 8 52 Information Ti mg kg-1 3490 170 5 5 68 Information U mg kg-1 2.42 0.28 11 6 69 Recommended V mg kg-1 73.0 3.7 5 19 44 Recommended Yb mg kg-1 2.08 0.18 9 6 64 Information Zn mg kg-1 140.6 9.5 7 85 48 Recommended

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8. RESULTS AND DISCUSSION

8.1 Overview of the results 92 laboratories provided results for the analysis of IAEA-158 by the final

deadline for the exercise. 101 sets of data were submitted (some laboratories reported data generated by multiple techniques) comprising 1102 analytical results for the determination of trace elements in IAEA-158 for a suite of 50 elements and methyl mercury (Appendix I). In comparison with previous sediment interlaboratory comparison IAEA 43315 numbers of participants is slightly lower while the number of elements stays identical. Z-scores were calculated for element with a recommended value assign and for which a minimum of 10 results were submitted, this results to 22 elements.

Of the 92 participating laboratories, the number of results for the suite of analytes designated as being of greatest interest to the study was as follows (the number of laboratory means reported is given in parenthesis): Al (26), As (50), Cd (66), Co (51), Cr (71), Cu (83), Fe (68), Hg (54), Li (12), Mn (71), Ni (63), Pb (75), Sb (15) Se (16), Sn (12) Sr (26), V (27), Zn (85) and (and methyl mercury (11)).

8.1.1. Moisture content Participants were requested to evaluate the moisture content of the test

material on a separate portion (not used for analysis) taken at same time as the sub-samples to be used for analysis. Results were to be reported to the IAEA after correction for the moisture content of the material.

IAEA-158 was subjected to freeze drying as part of its preparation. At the time of bottling, the moisture content of the material was below 1%. However, the material might absorb moisture from the atmosphere dependent upon local storage conditions and humidity levels. Consequently, users are advised to make a separate determination of the moisture content of the material whenever it is used for quality control purposes.

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8.1.2. Analytical methods In common with all open interlaboratory studies, a wide range of analytical

methodologies and finishes was used to provide data for the determination of trace elements in marine sediment IAEA-158. Broadly, this can be broken into three approximately equal groups, in this case: non-destructive techniques (XRF and NAA); plasma spectrometric methods (ICP-MS and ICP-AES) and atomic absorption methods.

Figure 2: Proportional distribution of analytical techniques used to analyse IAEA-158

FAAS21%

GFAAS13%

CVAAS 5%

Solid AAS1%

ICPAES13%

CVAFS1%

ICPMS20%

NAA16%

XRF10%

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If compared with the principal method used in the last interlaboratory comparison run for a similar matrix, IAEA 43315 (comparing with the previous exercise IAEA 43616 Tuna fish is useless as difference in methodology frequency would likely be due to the difference of level for many element) few comments can be done:

The downward trend in use of F-AAS observed in previous exercise stop as F-AAS represents 21% in comparison with 17.7% for IAEA 43315. The noticeable increased of the use of NAA and ICP-MS reported in IAEA 43315, is confirmed as both techniques have similar frequency in this exercise. For XRF the modest upward ship observe is continuing in this exercise (9.8% in IAEA 158 instead of 7.4% of IAEA 43315), if compared with IAEA 40517 (estuarine sediment produce in 2000) the frequency of XRF increase by 85%. This might just reflect an evolution of participating laboratory.

Regarding GF-AAS if no distinction is made between Zeeman and non Zeeman instruments, the frequency is unchanged, but the non Zeeman are now representing only 4% (7% in IAEA 43315) which is 33% of graphite furnace AAS data (51% for IAEA 43315). This might be explained as most of new instruments are now purchase with Zeeman.

The breakdown of usage of analytical techniques by analyte is presented on Table 4.

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Table 4. Frequency of use for different analytical techniques

Not

specified Method

Not specified AAS

FAAS GF-AAS

ZG-FAAS

CVAAS/ Hydride

Solid AAS

ICP-AES

CV-AFS

ICP-MS NAA XRF

Ag 3 1 6 Al 1 6 1 7 5 2 4 As 1 4 6 9 7 13 8 2 B 1 Ba 3 3 3 Be 2 Br 6 1 Ca 2 2 1 3 3 Cd 1 9 15 16 5 18 1 Ce 2 7 Co 1 8 2 7 10 10 9 4 Cr 2 19 4 10 8 12 9 7 Cs 2 6 Cu 2 1 36 4 8 12 12 8 Eu 2 5 Fe 1 1 28 1 13 6 9 8 Hf 1 6 Hg 32 9 2 6 5 K 2 1 2 5 3 La 2 8 Li 4 2 6 Lu 5 Mg 3 5 4 1 2 Mn 2 1 32 1 2 13 7 4 9 Mo 1 2 2 1 Na 3 1 2 6 2 Nb 1 1 Nd 2 4 Ni 2 1 23 1 8 10 11 7 Pb 2 1 17 10 16 10 15 4 Rb 2 7 4 S 2 Sb 1 1 6 7 Sc 2 8 Se 4 1 7 1 3 Si 3 Sm 2 7 Sn 1 2 3 5 1 Sr 1 7 7 3 8 Ta 6 Tb 1 5 Th 1 7 Ti 1 1 3 Tl 1 U 2 4 V 2 2 4 5 8 3 3 Y 1 Yb 1 5 Zn 1 1 39 4 12 12 8 8 Zr 2

FAAS: flame atomic absorption spectrophotometry; GFAAS: graphite furnace atomic absorption spectrophotometry; ZGFAAS: graphite furnace atomic absorption spectrophotometry with Zeeman background correction; CVAAS or Hydride.: cold vapour atomic absorption spectrophotometry or hydride generation; Solid-AAS: Solid Hg Analyser; ICPAES: inductively coupled plasma atomic emission spectrometry; CVAFS: cold vapour atomic fluorescence spectrophotometry; ICPMS: inductively coupled plasma mass spectrometry; NAA: neutron activation analysis; XRF: X-ray fluorescence.

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8.1.3. Laboratory performances For the assessment of each laboratory performance, an individual Z-score is

calculated according to the formula:

b

ai

sxxZ )( −

=

where xi is the reported laboratory mean concentration; xa is the assigned concentration calculated for the present exercise; and sb is the target standard deviation18,19.

This score effectively expresses the difference between the mean value of the laboratory and the assigned value from the overall laboratory results (i.e., the individual laboratory bias) with regard to the sb. The laboratory performance is as follows: • The results are considered to be satisfactory if Z ≤ 2 • The results are questionable when 2 < Z < 3 • The results are regarded as unsatisfactory when Z ≥ 3.

This type of score represents a simple method for evaluation of the performance of participating laboratories. This method of assessing laboratories has been accepted as a standard for ISO/IUPAC/AOAC19.

The choice of the target value for sb depends on the objectives for a given study. The criteria used in this report have been set so that laboratories passing the test (z-scores ≤±2) will have a laboratory bias equal to, or better than, 25% (sb = 12.5%). A fixed value of Sb has the advantage that the Z-scores derived from it can be compared from round to round to demonstrate general trends for a laboratory or a group of laboratories.

Calculated Z-score are presented in Table 6 (questionable Z-score (2<z<3) are in red and unsatisfactory Z-score (z≥3) are shaded. The data per element are summarised in Table 7 which reports the percentage of data falling into the three categories, as well as the percentage of reported datasets (total number of dataset=102)

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Table 8 summarizes the overall performance of individual laboratories. The proportion of z-scores falling in each category is given together with the total number of results they reported for this exercise. The percentage of z-scores satisfyingz< 3 was then used to assign the laboratory performance to a group level graded from 1 to 4 as follows:

Group 1 laboratories scoring z < 3 for ≥ 90% of the data; Group 2 laboratories scoring z < 3 for 75% to < 90% of the data; Group 3 laboratories scoring z < 3 for 50% to < 75% of the data; Group 4 laboratories scoring z < 3 for < 50% of the data.

It should be noted that the results are considered as acceptable if z<3. Z-

scores in the questionable range (2 < Z < 3) are technically acceptable but should be considered as a warning signal. Participants are encouraged to check their analytical processes, if all results reported are questionable or if they received questionable Z-scores for two exercises in a raw for the same element.

A total of 905 Z-scores was calculated over which 80% of data received Z-scores ≤ 2, and 90% of data received Z-scores < 3. This represents 102 dataset reported, in which 35 laboratories were able to produce datasets with all Z-score ≤ 2, and 54 laboratories with all Z-score <3. If compared with two previous exercises with similar matrix e.g. IAEA 40517 and IAEA 43315, there is a noticeable improvement. The portion of dataset reporting 100% of data with Z-score <3 in the previous exercise IAEA 40517 and IAEA 43315 was respectively 35% and 39%.

Also the proportion of laboratories that reported less than 50% of acceptable data represents only 4% (4 laboratories) compared to about 8% in the two previous exercises run on sediment samples17,15.

It should be noted that even if this is encouraging, part of these results could be also explained by the fact that the set of participants is not the same for the three exercises. Only a portion of participants is regularly participating, which makes the interpretation of the evolution of performance over time difficult.

23

Out of the 102 sets of data received, 13 didn’t include results for Quality Control as requested in the report form, and 17 provided only partial QC results. Results reported without QC are marked with a cross (X) on S-plot (Appendix II). From those plots we can see that results reported without QC are often at the extremities of the distribution (i.e. measurement bias is too high or too low). Unfortunately, even if these results turned out to be accurate, they are invalid in the absence of quality control data. In order to validate their results, all laboratories should at least systematically realise the following Quality Control steps: (1) analyse procedural blank to control the possible sources of contamination; (2) analyse standard reference materials (i.e., RMs) with a similar matrix and approximately the same concentration level as in the samples being analysed10,11. This should be done for each series of analysis (i.e., batch of digested samples), and these quality controls samples should be analysed at regular intervals during the measurements.

It is satisfying to notice that major part of participating laboratories have used as Quality Control sample IAEA 433 (previous exercise) reference material, followed by IAEA 405 and MESS-3 (NRCC, Canada).

As it can be seen from S-plot (Appendix II) results obtained for Ag, As, Ca, Cd, Co, Cu, K, La, Na, Ni, Pb, Rb, Sn and Zn are generally quite well clustered around the reference value (i.e no significant positive or negative bias observed). In contrast the distribution exhibits negative bias for Al, Cr, Fe, Mn, Sr and V. As it will be discussed later (Section 8.2) the effect of digestion for those elements might explain the distribution. As already observed in previous exercises15,17 Hg distribution exhibit positive bias with numerous extreme values (i.e 8 laboratory received Z-scores >6).

It appears that 85% of laboratories measuring Cu, Fe, and Zn received Z-score ≤ 2. This result shows that those elements are easily analysed. On the other hand Cd and Hg have respectively 20% and 25% of reported data outside of the accepted range (i.e. Z-score >3), probably reflecting unresolved analytical problems.

High-biased results could originate from contamination during either sample preparation (e.g., digestion step) or analysis. The laboratories concerned should carefully check analytical procedures (e.g., quality of purified water and reagents) and try to improve the cleanliness of the working environment. For example, dust is the most common atmospheric source of contaminants for trace elements in laboratories. Laboratories should also develop an effective scheme for cleaning laboratory-labware that generally includes a soap wash, an acid wash and thorough rinsing with purified water free from trace elements20.

24

Erroneous calibration standards may be another source of bias. For instance, it is important to note that losses can occur in low-concentration working standard solutions, which would result in overestimates of the concentrations of elements in the samples (e.g., standard solutions should not be stored for an extended period of time). Only standards (CRM) with stated SI traceability should be used for calibration purposes.

Laboratories with poor results should carefully check all laboratory procedures, equipment and instruments.

Table 5. Summary of performance by element

z≤2

(%) 2<z<3

(%) z≥3

(%) Participation

(%) Ag 78 0 22 9 Al 69 0 31 25 As 84 6 10 49 Ca 64 18 18 11 Cd 67 13 20 59 Co 84 4 12 50 Cr 76 10 14 70 Cu 89 6 5 81 Fe 87 6 7 67 Hg 66 9 25 52 K 77 8 15 13 La 100 0 0 10 Mn 82 14 4 70 Na 79 7 14 14 Ni 84 8 8 62 Pb 77 15 8 74 Rb 100 0 0 13 Sb 64 21 14 14 Sn 58 25 17 12 Sr 73 27 0 25 V 70 26 4 26 Zn 89 5 6 83

25

Table 6. Assessment of laboratories based on z-scores

Lab

Code Ag Al As Ca Cd Co Cr Cu Fe Hg K La Mn Na Ni Pb Rb Sb Sn Sr V Zn

1 -0.30 2 -1.26 -5.26 -0.99 -0.37 -0.81 -1.28 -2.70 -0.27 -0.99 -1.23 -5.80 -2.42 -4.21 -0.87 -0.56 -6.93 -2.69 -2.81 -2.50 -0.56 3a 0.37 0.03 0.36 0.10 -1.21 0.75 3b -1.17 -0.43 -0.14 0.60 0.42 -0.64 2.19 3c 1.60 -0.63 0.06 -0.91 -0.11 -0.39 0.23 0.17 0.90 -1.03 4 0.18 5 1.60 -0.13 0.60 4.42 0.22 -0.75 -0.55 3.11 11.39 -0.05 0.09 0.20 6 -0.81 7 -1.10 1.14 -0.47 0.68 -0.07 -3.81 0.69 0.84 -0.28 0.00 0.13 -0.08 8 -0.38 2.16 0.64 -2.09 0.59 0.51 1.63 0.44 0.80 1.00 0.71 9 0.34 -0.81 -4.93 -1.95 -5.05 10 0.54 0.48 15.07 1.44 0.86 -0.88 1.75 11.90 -0.68 1.26 2.92 2.89 -2.82 3.49 11 -0.55 -0.02 -0.08 0.83 0.31 2.51 -0.90 -0.86 -0.10 -0.68 0.34 12 -1.26 0.11 -0.84 0.49 0.51 0.46 0.43 0.34 -0.04 1.62 0.24 -0.11 0.58 0.15 0.33 0.57 0.40 -0.14 2.24 0.70 0.01 0.09 13 1.85 0.32 -0.03 -2.40 -1.80 2.08 14 -3.53 -1.49 1.10 -1.29 0.04 -0.09 0.02 -2.72 -0.88 -1.63 15 0.80 -0.92 -0.45 0.00 1.43 -0.12 -0.66 -0.09 -0.10 -0.84 16 -0.32 17 4.83 -1.10 -3.01 0.08 -0.98 -0.51 -2.23 -1.09 -0.78 -0.27 18 -1.36 -1.79 -0.04 6.14 0.36 -1.10 -0.56 2.07 19 -4.67 -0.96 0.04 1.14 -1.88 0.48 -0.54 3.49 -0.86 -0.72 -1.03 -0.22 -1.59 -1.17 -0.31

26

Lab


20 0.49 -0.26 0.25 -1.05 -0.90 -0.05 0.01 -0.11 0.27 -0.07 -0.12 1.53 -1.81 0.35 21 -1.10 -0.61 -1.38 2.91 -2.41 -0.58 -0.29 22 -0.19 0.28 -0.29 -2.00 0.81 -0.03 0.19 23 -6.91 -4.89 -3.49 -0.82 -2.92 -1.57 -2.00 0.76 24 -2.51 0.54 0.94 0.34 -0.13 0.84 0.13 -0.10 0.80 0.98 -0.06 -0.09 8.95 25 1.59 0.00 0.26 0.18 26 -0.19 27 -0.45 1.38 0.32 -0.12 1.39 0.41 1.19 1.15 1.10 -0.40 1.76 -0.04 28 0.33 1.01 2.89 -4.19 0.08 1.52 0.38 0.88 10.53 -0.32 -0.57 3.06 3.73 1.42 -0.98 2.18 -0.08 0.15 29 -3.02 0.03 0.51 0.72 0.52 -0.91 0.29 -0.44 0.16 -0.13 2.15 -2.28 0.19 30 0.07 -0.60 -1.53 -0.54 -0.11 -0.46 0.00 -0.20 0.21 31a -0.40 31b -0.85 31 -1.45 -1.22 -0.74 -0.92 -0.88 -2.20 0.31 -1.46 32 1.78 -1.52 1.20 1.18 1.13 0.09 0.06 33 -5.56 -1.44 -0.32 -0.91 0.14 -0.96 0.75 -1.71 -1.36 -0.84 -2.65 -0.23 -1.35 -2.93 -1.31 34 -1.35 -3.47 -2.83 -4.05 -3.87 -4.58 -5.12 -4.84 -2.33 35 -1.15 -2.28 -0.30 -0.05 -0.07 -0.38 -0.44 -0.57 0.02 -0.85 0.00 -0.98 0.57 36 1.29 4.51 11.22 -2.50 -1.82 0.40 37 4.89 1.01 -3.12 -2.74 -0.29 -1.71 -0.73 38 -1.60 0.38 -1.94 -1.80 1.59 -0.67 39 0.80 0.70 -2.13 -3.38 -0.36 -1.68 -0.28 -2.51 -1.53 -1.54 -2.17 -1.04

27

Lab


40 1.60 -1.95 -1.47 -1.85 -3.06 -2.13 -1.49 -1.42 41 0.53 42 -5.13 1.28 -3.11 5.82 -2.27 -0.48 -1.15 -3.96 -1.54 -0.51 0.59 -2.02 -0.91 43 1.30 0.79 0.47 0.51 -0.95 -0.64 12.48 -1.17 -2.12 -0.64 -2.73 -0.66 44 0.80 0.99 0.10 -0.08 0.36 -0.68 -0.28 0.00 0.09 -0.47 0.08 0.12 -0.06 45a -0.12 1.18 -0.70 0.40 -0.66 38.55 0.36 0.14 -1.27 0.18 45b -0.14 -1.27 -0.41 0.39 45c -0.01 -0.28 -0.73 0.50 46 -0.49 0.92 -0.02 0.43 0.29 -0.21 -0.62 0.01 -0.46 0.44 0.75 1.08 47 -1.14 1.67 -0.01 -0.64 2.28 1.06 0.03 48 0.39 -0.11 1.16 0.08 0.66 0.04 0.19 0.75 0.18 0.03 0.97 49 1.88 4.62 -1.18 -0.19 -0.40 0.53 0.45 -0.79 50 -6.13 -1.07 -0.27 -3.10 -3.06 0.50 -1.01 -0.63 -2.38 -0.86 -0.24 -3.54 -2.52 -3.47 -0.54 51a 0.64 -1.35 0.27 1.33 7.80 2.22 2.24 -1.76 51b -0.02 -0.56 -0.09 0.11 51c -0.30 2.99 6.28 0.35 0.80 0.39 0.85 0.71 1.27 1.80 0.61 -1.14 -1.86 52 -0.22 8.41 1.92 -0.41 0.18 0.04 0.18 0.86 -0.34 -0.07 0.42 0.57 53 1.89 0.34 0.34 -0.63 -0.01 -0.79 0.61 0.02 0.04 0.40 0.88 -0.25 -0.27 54 3.04 1.68 -0.54 0.02 -1.11 2.47 0.04 55 -0.60 0.52 -3.63 0.15 -1.96 -0.69 -0.34 1.81 0.07 0.91 56 -1.26 -2.95 0.49 0.45 2.43 -0.33 57 -2.03 0.28 0.51 0.72 0.67 0.26

28

Lab


58 -0.43 -2.39 -2.72 -0.91 2.30 -0.53 1.56 59 1.45 0.54 -0.10 0.72 1.34 0.57 2.79 60 -0.68 -1.54 -0.82 -1.41 0.69 -1.45 1.83 61 -0.64 3.54 -0.86 -2.83 1.80 -2.11 -2.15 -1.28 0.05 -1.02 62 -5.40 -0.69 1.62 -0.17 -0.48 1.36 -2.61 0.97 63 -0.19 -0.19 -2.77 -0.61 2.37 -0.73 -0.56 0.70 0.17 0.92 -1.64 -1.00 -1.70 0.63 64 0.23 -0.56 0.60 -0.03 -0.26 -0.18 -0.04 0.12 -0.03 65 0.38 -0.46 -0.22 -0.40 0.42 -1.08 0.13 0.22 2.12 -0.21 -0.38 1.04 -0.33 0.68 -0.20 -0.13 0.04 66 0.55 -0.96 -1.59 0.58 3.85 0.25 67 -5.12 -3.28 135.43 1.81 -1.20 68 35.78 -0.85 3.00 -0.71 -0.37 0.69 -0.66 -0.48 0.30 -0.83 1.43 0.05 0.56 69 -5.56 -4.03 -3.92 6.24 -3.70 -3.03 -3.86 -4.89 -1.29 70 0.04 8.17 1.97 0.96 0.75 0.19 0.07 0.29 1.16 0.03 -0.08 71 -3.14 -0.71 0.65 2.88 -2.02 1.46 0.87 1.88 1.25 72 -4.32 -0.71 -0.03 -3.33 -0.07 73a 0.07 0.15 0.34 73b 0.62 1.06 0.66 73 0.45 0.39 0.10 -0.19 0.81 0.72 0.35 -0.40 74 2.34 -3.15 -0.95 1.00 -0.34 -0.87 -2.63 1.80 0.35 -2.00 75 6.31 1.58 1.20 0.09 0.41 -0.29 0.58 0.59 2.60 3.45 0.83 -0.34 76 -1.57 1.06 -2.20 0.73 -2.64 -0.68 77 1.52 2.85 0.59 8.89 0.45 1.13 -1.82 1.16

29

Lab


78 -0.59 -0.15 -1.19 -0.26 0.28 0.09 -0.14 -0.30 -0.38 -1.36 -1.15 0.09 0.47 79 0.06 -2.32 -2.13 -0.73 0.99 80 0.59 -0.42 -0.04 -0.11 -0.77 -0.59 -0.80 0.37 81 -1.24 -2.45 -1.79 -4.50 0.84 82 -1.04 1.16 -0.71 -0.13 -0.33 -0.10 1.00 -0.56 -1.08 0.92 -0.35 0.08 0.73 -0.36 -0.13 -0.15 -0.16 83 1.07 1.16 1.84 -0.96 -0.44 -1.16 -1.02 -1.13 -1.15 -1.04 -0.45 84 -2.59 -0.61 -0.06 -0.01 0.76 -0.46 -0.19 0.54 -0.26 85 -1.37 0.74 -4.48 -4.45 -2.78 0.47 -2.63 -2.30 -2.70 86 0.17 0.33 0.30 0.49 0.21 -3.59 -0.36 0.06 0.52 -0.53 0.23 87 -1.22 -5.63 -0.64 -0.21 -0.42 -3.51 0.52 -2.75 -1.20 -4.07 88 -0.18 0.76 0.19 11.40 0.35 89 1.55 -0.07 1.05 -0.05 -2.25 -0.01 90 40.07 111.54 6.51 -2.04 -2.02 1.00 -6.47 -2.93 -3.49 91 -3.07 -0.88 -0.46 2.40 -1.10 1.32 92a 0.13 -0.18 -0.78 0.62 -0.32 0.41 -0.07 -0.44 0.36 0.70 0.17 0.90 -0.66

z ≤ 2: Performance is considered to be acceptable; 2< z <3: The results are of questionable quality (red font); z ≥ 3: Performance is unacceptable (shaded)

30

Table 7. Overall assessment of laboratory performance Lab Code

N of IzI≤2

N of 2<IzI<3

N of IzI>3

N of Z-score

% of IZI <3

GROUP

1 1 0 0 1 100 1 2 11 5 4 20 80 2 3a 6 0 0 6 100 1 3b 6 1 0 7 100 1 3c 10 0 0 10 100 1 4 1 0 0 1 100 1 5 9 0 3 12 75 2 6 1 0 0 1 100 1 7 11 0 1 12 92 1 8 9 2 0 11 100 1 9 3 0 2 5 60 3 10 8 3 3 14 79 2 11 10 1 0 11 100 1 12 21 1 0 22 100 1 13 4 2 0 6 100 1 14 8 1 1 10 90 1 15 10 0 0 10 100 1 16 1 0 0 1 100 1 17 7 1 2 10 80 2 18 6 1 1 8 88 2 19 13 0 2 15 87 2 20 14 0 0 14 100 1 21 5 2 0 7 100 1 22 7 0 0 7 100 1 23 3 2 3 8 63 3 24 11 1 1 13 92 1 25 4 0 0 4 100 1 26 1 0 0 1 100 1 27 12 0 0 12 100 1 28 12 2 4 18 78 2 29 10 2 1 13 92 1 30 9 0 0 9 100 1 31a 1 0 0 1 100 1 31b 1 0 0 1 100 1 31 7 1 0 8 100 1 32 7 0 0 7 100 1 33 12 2 1 15 93 1 34 1 2 6 9 33 4 35 12 1 0 13 100 1 36 3 1 2 6 67 3 37 4 1 2 7 71 3 38 6 0 0 6 100 1 39 8 3 1 12 92 1 40 6 1 1 8 88 2 Group 1 laboratories with Z < 3 for ≥ 90% of the data Group 2 laboratories with Z < 3 for 75% to < 90% of the data Group 3 laboratories with Z < 3 for 50% to < 75% of the data Group 4 laboratories with Z < 3 for <50% of the data

31

Lab Code

N of IzI≤2

N of 2<IzI<3

N of IzI>3

N of Z-score

% of IZI <3

GROUP

41 1 0 0 1 100 1 42 7 2 4 13 69 3 43 9 2 1 12 92 1 44 13 0 0 13 100 1 45a 9 0 1 10 90 1 45b 4 0 0 4 100 1 45c 4 0 0 4 100 1 46 12 0 0 12 100 1 47 6 1 0 7 100 1 48 11 0 0 11 100 1 49 7 0 1 8 88 2 50 8 2 5 15 67 3 51a 5 2 1 8 88 2 51b 4 0 0 4 100 1 51c 11 1 1 13 92 1 52 11 0 1 12 92 1 53 13 0 0 13 100 1 54 5 1 1 7 86 2 55 9 0 1 10 90 1 56 4 2 0 6 100 1 57 5 1 0 6 100 1 58 4 3 0 7 100 1 59 6 1 0 7 100 1 60 7 0 0 7 100 1 61 6 3 1 10 90 1 62 6 1 1 8 88 2 63 12 2 0 14 100 1 64 9 0 0 9 100 1 65 16 1 0 17 100 1 66 5 0 1 6 83 2 67 2 0 3 5 40 4 68 11 1 1 13 92 1 69 1 0 8 9 11 4 70 10 0 1 11 91 1 71 6 2 1 9 89 2 72 3 0 2 5 60 3 73a 3 0 0 3 100 1 73b 3 0 0 3 100 1 73 8 0 0 8 100 1 74 6 3 1 10 90 1 75 9 1 2 12 83 2 76 4 2 0 6 100 1 77 6 1 1 8 88 2 78 13 0 0 13 100 1 79 3 2 0 5 100 1 80 8 0 0 8 100 1 Group 1 laboratories with Z < 3 for ≥ 90% of the data Group 2 laboratories with Z < 3 for 75% to < 90% of the data Group 3 laboratories with Z < 3 for 50% to < 75% of the data Group 4 laboratories with Z < 3 for <50% of the data

32

Lab Code

N of IzI≤2

N of 2<IzI<3

N of IzI>3

N of Z-score

% of IZI <3

GROUP

81 3 1 1 5 80 2 82 17 0 0 17 100 1 83 11 0 0 11 100 1 84 8 1 0 9 100 1 85 3 4 2 9 78 2 86 10 0 1 11 91 1 87 6 1 3 10 70 3 88 4 0 1 5 80 2 89 5 1 0 6 100 1 90 1 3 5 9 44 4 91 4 1 1 6 83 2 92a 13 0 0 13 100 1 Group 1 laboratories with Z < 3 for ≥ 90% of the data Group 2 laboratories with Z < 3 for 75% to < 90% of the data Group 3 laboratories with Z < 3 for 50% to < 75% of the data Group 4 laboratories with Z < 3 for <50% of the data

8.2 Laboratory performance for selected trace elements In order to examine the relative precision and accuracy of different instrumental

techniques, the complete data set for selected elements (i.e. all reported laboratory means) was classified according to the analytical techniques used and represented as multiple box-and-whisker plots (Figs. 3 to 17; see section 7.1 and Table 2 for instrument codes/names). On these graphs, a box encloses the middle 50% of the data (i.e. between the 25 and 75 percentiles), the median is indicated by a horizontal line crossing the box, and the mean value is represented as a black point. The dashed line indicates the limits of variability in the overall laboratory mean resulting from this interlaboratory study (i.e., assigned mean ± one standard deviation). The mean sometimes falls outside the box because of the inclusion of data that would normally be considered as outlying. The whiskers represent the 10 and 90 percentiles, but are only displayed when there are at least 10 measurements in the data set. The number of measurements represented by each data set is reported above the mean (black dot) or the median (horizontal line crossing the box). In order for the data associated with a given technique to be meaningful, a minimum of five independent laboratory means was required before a box could be plotted.

33

8.2.1. Aluminium Figure 3 displays the data obtained for aluminium analysis in IAEA-158. The figure

presents the data by technique (the 3 left hand plots) and as a function of digestion strategy.

The Figure 4 shows the full distribution of reported mean (horizontal line representing laboratory standard deviation), reported mean with partial digestion are in pink, X represent data reported without QC. It is evident that where HF was not used as part of the destructive sample digestion methodology, low values were obtained. The Cofino model was run again without data produced without total digestion. The new calculated mean (total digestion) is found at 51.8 g kg-1 instead of 50.2 g kg-1. While running the model with the non total (i.e. no HF) dataset the calculated mean was found to be 18.1 g kg-1 confirming the clear bimodal distribution.

6

7

5 12

6

56

7

5 12

6

5

FAAS ICP-AES ICP-MS HF No HF Non Desturctive

Method Code

0

20

40

60

80

100

120

Al co

ncen

tratio

n (mg

/g)

Figure 3. Aluminium results derived from different methods

34

0 10 20 30 40 50 60 70 80Al Concentration (mg/g)

Labo

ratorie

s

Total or Non destructive Partial311.3

Figure 4. Total vs Partial reported mean for Aluminium

Only a quarter of the participants provided data for Aluminium, 70% of reported

mean received a │Z│≤ 2, but this represent 90% of acceptable values if reported to the reduced dataset. All data produced with a partial digestion received Z-scores from -4.5 to -6.9, participant are advised to use complete digestion to achieved accurate results for Al.

This element is often used for “normalising” sediment trace element data in pollution studies in order to correct for the grain size effect on natural metal variability in different samples, so that anthropogenic metal contributions may be assessed. The applicability of this procedure is closely linked to the accuracy of Al results.

8.2.2. Arsenic Arsenic was analysed by 49 laboratories using 7 distinct techniques. An excellent

level of agreement was seen between the techniques (Fig. 5) employed. Median results of ZGF-AAS, Hydr-AAS, ICP-AES and ICP-MS lay within the ±1 sigma range of the mean value derived from the Cofino method, while NAA median fall just below. It is possible that lower NAA values stem from an overcorrection due to the presence of bromine in the samples (Br is an order of magnitude more concentrated than As), which may give rise to spectral problems due to inadequate resolution of the two peaks or limitations with the evaluation software. In general, the level of accuracy was excellent, with more than 80%

35

of laboratories returning z-scores ≤2. About half of the participants attempted to determine As in this sample. This confirms the generally good results observed for As on previous interlaboratory comparison, with a noticeable improvement of results obtained by Hydr-AAS (negative bias were observed in IAEA 43616 and IAEA 43315).

776

9 13

8

ZGF-AAS Hydr-AAS ICP-AES ICP-MS NAAMethod Code

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

As co

ncen

tratio

n (µg

/g)

Figure 5. Arsenic results derived from different methods

8.2.3. Cadmium In general, a reasonable agreement was obtained between the different methods

used for determining Cd in IAEA-158 (Fig. 6), with data obtained from ICP-AES exhibiting slightly higher values than the other methods. There is a known interference problem of As on Cd by ICP-AES (indeed Al and Fe may also interfere). The ratio of As to Cd in this material is 30.8, so it is possible that the overestimation exhibited in the ICP-AES may be due to inadequate correction of spectral interference. This positive bias was also observed in previous exercise. Results reported with F-AAS are in relatively good agreement with reference value, which is an improvement if compared with IAEA 43315. This might be explained by the significant difference in concentration (0.372 µg g-1 for IAEA 158 compared with 0.153 µg g-1) which makes F-AAS an appropriate method in regards of detection limit. The majority of laboratories used graphite furnace AAS techniques (with or without Zeeman correction). The data spread was highest in the case

36

of GF-AAS without Zeeman-correction, although the median fell just outside the acceptable range for data. The 18 laboratories using ICP-MS demonstrated reasonable agreement for this element. 60% of the participants reported data for Cd and of these 67% of the data was found to be accurate.

5

15

15

5

18

F-AAS ZGF-AAS GF-AAS ICP-AES ICP-MS

Method Code

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800

Cd co

ncen

tratio

n (µg

/g)

Figure 6. Cadmium results derived from different methods

8.2.4. Chromium Figure 7 shows the distribution of results for the determination of chromium as a

function of the measurement technique and also as a function of digestion strategy (the three right hand box plots). It is evident that the results from XRF analysis over-estimate the chromium content of the material. There is also a suggestion that digestion strategies that did not incorporate HF in the digestion media lead to lower values, but the trend is not statistically significant as the distributions overlap. As for Al Cofino model was rerun with restricted dataset and the calculated mean is 75.0±5.7 µg g-1 which is almost identical to the mean obtain with the full dataset 74.4±5.8 µg g-1. While running the model with non HF data the mean is 64.8±8.6 µg g-1. The negative bias of the distribution (see Appendix II) can not be explained completely by the use of HF as distribution overlap. But it appears that wet digestion technique could underestimate the Cr concentration. The accuracy of Cr is strongly linked to the sample treatment, not only HF

37

(even if it appears that it can help to get total Cr in solution) but maybe also temperature, pressure….Participants are encourage to validate their digestion protocol with the use of certified reference material. As already mention a large number of bias results were reported without QC (marked with X on S-plot Appendix II). With the exception of XRF, as noted above, all of the method data distributions overlap, indicating that they are not statistically different. Three quarters of the results obtained for chromium showed z-scores ≤2 and a little more than 70% of the participants provided data for this analyte.

1910 8

12 9

7

32

22

15

F-AASZGF-AAS

ICP-AESICP-MS

NAAXRF

HFNo HF

No digestion

Method Code

0

20

40

60

80

100

120

140

Cr co

ncen

tratio

n (µg

/g)

Figure 7. Chromium results derived from different methods

8.2.5. Copper, Cobalt, Nickel and Zinc

These are examples of well-grouped data with generally good agreement between

the different analytical methods used (Figs.8 to 11). Such well-grouped data are typically obtained for Cu, Co, Ni and Zn in interlaboratory studies on sediment (IAEA 40517, IAEA 43315). With the exception of Ni determined by ICP-AES all medians and most of means fall inside the mean ± 1SD. The effect of HF was tested for Ni but it was found to be null.

38

121236 8 128

F-AAS ZGF-AAS ICP-AES ICP-MS XRF

Method Code

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Cu co

ncen

tratio

n (µg

/g)

Figure 8. Copper results derived from different methods

8 710 10

9

F-AAS ZGF-AAS ICP-AES ICP-MS NAA

Method Code

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Co co

ncen

tratio

n (µg

/g)

Figure 9. Cobalt results derived from different methods

39

2325

23258

1011

730

F-AAS ZGF-AAS ICP-AES ICP-MS XRF HF No HF

Method Code

0.0

10.0

20.0

30.0

40.0

50.0

Ni co

ncen

tratio

n (µg

/g)

Figure 10. Nickel results derived from different methods

398

398

1212

8

F-AAS ICP-AES ICP-MS NAA XRF

Method Code

0

20

40

60

80

100

120

140

160

180

200

Zn co

ncen

tratio

n (µg

/g)

Figure 11. Zinc results derived from different methods

40

Cu and Zn are the most “popular” elements with 81% and 83% of participant reporting data for those elements. The well clustered distributions are reflected in Z-score with an impressive 89% (for Cu and Zn) of dataset receiving │Z│≤ 2. As well only 4 laboratories for Cu and 5 laboratories for Zn returned unsatisfactory Z-scores (representing 5% and 6% respectively). Co and Ni were analysed by less participants (51 and 63 datasets respectively) but the well grouped data is also reflected in Z-score with 84% of reported results receiving │Z│≤ 2.

8.2.6. Lead

17

1616

17

1616

10

15

F-AAS ZGF-AAS GF-AAS ICP-AES ICP-MS

Method Code

0.0

10.0

20.0

30.0

40.0

50.0

60.0

Pb co

ncen

tratio

n (µg

/g)

Figure 12. Lead results derived from different methods

The majority of the data for lead falls within the ±1 standard deviation interval

about the Cofino mean irrespective of the analytical technique employed. The slight negative bias observe for F-AAS might be explained by anionic interferences. If no chemical modifier is added then there is a significant suppression of the Pb signal. About three quarters of laboratories provided data for Pb and from this results almost 80% obtained z-scores ≤2, and 8% obtained unsatisfactory z-score >3.. This is an improvement if compared with previous exercise, as more than 20% of reported data for Pb in IAEA 43315 were unsatisfactory. One of the reason might be that Pb level in IAEA 158 is 50% higher than in IAEA 433.

41

8.2.7. Manganese and Iron Figure 13 and 14 shows the distribution of results for the determination of Fe and

Manganese as a function of the measurement technique and also as a function of digestion strategy. There is a suggestion that digestion strategies that did not incorporate HF in the digestion media lead to lower values. As for Al Cofino model was rerun with restricted dataset, results are presented below. Mn (µg g-1) Fe (µg g-1) Entire dataset 356 ± 24 26.3 ± 1.4 Total (HF) and non destructive 358 ± 23 26.8 ± 1.3 Partial (no HF) 267 ± 25 23.9 ± 1.6

The effect of “weak” digestion is clearer for Mn than for Fe, i.e. the relative difference between Total (and non destructive) and Partial Cofino mean is around 20% for Mn and 10% for Fe. The means calculated with full or restricted dataset do not differ significantly, and as distributions do slightly overlap it was decided to use the entire dataset to produce the consensus mean for both elements. The negative biases observe for F-AAS and ICP-AES on both elements are most probably linked to the digest procedure rather than to the method. Effectively the low data observe for those distribution were almost all reported by laboratories that did not use HF. As for Cr it appears that wet digestion technique could underestimate Fe and Mn concentration. Participants are encouraged to validate their digestion protocol with the use of certified reference material, as already mentioned a large number of bias results were reported without QC (marked with X on S-plot Annex II).

42

3213

2932

13

297

9

27

12

F-AASICP-AES

ICP-MSXRF

HFNo HF

Non destructive

Method Code

0

100

200

300

400

500

Mn co

ncen

tratio

n (µg

/g)

Figure 13. Manganese results derived from different methods

28 136 9 8 24

25

17

F-AAS ICP-AES ICP-MS NAA XRF HF No HF No digestionMethod Code

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

Fe co

ncen

tration

(mg/g

)

Figure 14. Iron results derived from different methods

43

8.2.8. Mercury As can be seen from figure 15, all methods used for the determination of mercury

in this sediment material provided consistent results. The majority of laboratories used the CVAAS technique. It is clear from the plot that a minority of these laboratories overestimated the mercury content in IAEA-158. This tendency of positive bias of the distribution is recurrent in mercury determination in sediment15,17 and is mainly linked to contamination (of reagent or lab ware) and/or erroneous calibration standard. As already seen in IAEA 43315, the positive bias is more evident on CV-AAS than on CV-AFS which is much more sensitive. One reason could be that analysts using high sensitive instrument as AFS are more aware of contamination sources and take more precaution to avoid it.

Just over half of the participants submitted data for mercury. Of these, 65% were deemed to be accurate and 25% of reported data are unacceptable, reflecting that Hg is a difficult element to determine in sediment samples. Participant that received bad Z-score are encouraged to check their blanks and calibration standard. Again large portions of unacceptable data were reported without QC.

3131 96

CV-AAS Solid-AAS CV-AFS

Method Code

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

Hg co

ncen

tratio

n (µg

/g)

Figure 15. Mercury results derived from different methods

44

The relative in homogeneity of the sample report in Section 4 is not reflected in

participant results. The average relative standard deviation reported is 7%. But as already stated the unhomogeneity is linked to spurious “high” values, so it is possible that participants did not get those “high” values. Another possibility is that participants decided to not report the value of a replicate if it was considered as outlier.

8.2.9. Strontium and Vanadium: About 25 participants only reported data for Sr and V. The box and Whisker plots

are useless when few data are available, so it was decided to present data (figure 16 and 17) using the entire data set. Reported means are plotted as dot (blue for partial digestion, pink for HF digestion and grey for non destructive techniques), the horizontal dash represent the median and the horizontal dashed line indicates the limits representing ±1 SD of the calculated Cofino mean. In some case methods were combined to get more data (i.e. XRF and NAA or Zeeman and non Zeeman graphite furnace).

From both graphs it can be seen that the negative bias observe in the distribution (S-plot Appendix II) is linked mainly to the dissolution procedure. Even if for Sr some data from non destructive technique appears bias low as well. As already done for other elements (Al, Cr, Fe and Mn) the Cofino model is rerun with a restricted dataset. Sr (µg g-1) V (µg g-1) Entire dataset 473 ± 25 73.0 ± 4.6 Total (HF) and non destructive 473 ± 25 73.0 ± 3.7 Partial (no HF) 372 ± 72 49.0 ± 4.0

For Sr there is no difference between calculated mean and standard deviation using full or restricted dataset, and anyway as for Fe and Mn the small overlapping of distributions (HF and No HF) would suggest keeping the entire dataset.

For V, the only difference is on the standard deviation, and as the use of HF is more clearly affecting results, it was decided to use restricted dataset to produce the mean and the standard deviation.

Participants are encouraged to use HF in wet digestion procedure to help to get accurate results for Sr and V, and to use reference material of similar matrix to validate their results.

45

0

100

200

300

400

500

600

700

Stron

tium

conc

entra

tion (

µg g-1

)

ICP-AESICP-MS XRF+NAA No HFHF

Figure 16. Strontium results derived from different methods

0

15

30

45

60

75

90

105

Vana

dium

conc

entra

tion (

µg g-1

)

ICP-AESICP-MS XRF+NAA No HFHF(Z)GF-AAS

Figure 17. Vanadium results derived from different methods

46

9. METHYLMERCURY Ten laboratories had reported a total of 11 results for methylmercury (MeHg) by the deadline for this exercise. A twelfth set of data was submitted whilst the report was being prepared and it has exceptionally been included in this report because of the importance of methylmercury data to the wider analytical community. Various separation procedures and detection systems were used for this analysis and a list of the participants with a description of the method they used is given in

47

Table 8. The aim of this part of the study was to compare results for methylmercury obtained by different methods. Although speciation analysis is becoming more popular within the marine analytical community, it remains a special area and consequently, the purpose of this section is somewhat different to the rest of the intercomparison.

In the very first step of the analytical process, MeHg must be released from the binding sites on the surface of the sediment particles. Three separate approaches were used to achieve this aim: distillation, alkaline digestion and acid leaching. Once the species had been extracted into solution by these means, further processing methodologies included solvent extraction, derivatisation by aqueous phase ethylation or grignard and GC separation. The instrumental techniques employed included cold vapour (CV) atomic absorption spectrophotometry (AAS); gas chromatography (GC) combined with atomic fluorescence spectrophotometry (AFS); GC with atomic emission detection (AED); GC combined with ICP-MS and liquid chromatography (LC) with CV-AFS. It should be noted that 8 of the 12 results were obtained by GC-AFS. Only one laboratory provided results that did not involve a chromatographic separation. The method used was CV-AAS which estimates organic mercury as the difference of total mercury and inorganic mercury following a step-wise analytical procedure.

The results obtained are reported in Appendix I. The laboratories’ means are also plotted in ascending concentration (Appendix II). All laboratories reported numerical values and Laboratory N°92 reported two set of data using different analytical techniques. A total of 12 means was obtained, results ranged between 1.01 and 11.9µg kg-1.

The data set was analysed using Cofino model (see Section 7.2) and a new version of Cofino model which uses a bandwidth estimator (BWE)14 instead of the standard deviation reported by the participants.

48

Table 8. List of laboratories and analytical methods used for methylmercury determinations.

Lab. code Methodology

Instrumental

technique a

Detection limit

(ng g-1) CRM used

1 Alkaline digestion KOH/MeOH, Aqueous phase ethylation, Tenax

GC-AFS 0.03 IAEA 405

4 Distillation, Aqueous phase ethylation, Tenax GC-ID-ICPMS

Not Reported

IAEA 405

20 Acid leaching (H2SO4/KBr/CuSO4), extraction Toluene, Gringnard

GC-AED 5 Not Reported

26 KBr/ CH2Cl2 extraction, back extraction water Aqueous phase ethylation, Tenax


32 Acid leaching (H2SO4/KBr/CuSO4), extraction CH2Cl2, back extraction water Aqueous phase ethylation, Tenax


36 Total Hg and inorganic Hg measured after SnCl2 reduction. MeHg calculated as Org-Hg

CV-AAS (Org-Hg)

0.4 IAEA 433

65 Acid leaching (H2SO4/KBr/CuSO4), extraction CH2Cl2, back extraction water Aqueous phase ethylation, Tenax


68 Distillation, Aqueous phase ethylation, Tenax

GC-AFS 0.3 CRM 580

83 Extraction CH2Cl2, back extraction waterAqueous phase ethylation

HS-GC-AFS

0.001 IAEA 433

92 Leaching HNO3, extraction CH2Cl2,back extraction water Aqueous phase ethylation, Tenax

GC-AFS 0.2 IAEA 405

92b Alkaline digestion KOH/MeOH, extraction HCl/CH2Cl2, back extraction water Aqueous phase ethylation, Tenax

GC-AFS 0.2 IAEA 405

93 Acidic Thiourea Leaching LC-CV-AFS

Not Reported

Not Reported

a GC: gas chromatography; AFS: atomic fluorescence spectrophotometry; AED: atomic emission detector; ID- ICP-MS: Isotope dilution Induced Coupled Plasma Mass Spectrometry, HS: Head Space, AAS: atomic absorption spectrophotometry, CV: cold vapour, LC: liquid chromatography.

49

While looking at the dataset; Laboratory N°20 appears as outlier (identified by Grubs and Dixon test). This participant was the only laboratory that used the Grignard derivatisation procedure, followed by GC-AED. This extraction and derivatisation procedure also returned high results in the IAEA-433 intercomparison exercise15. Since they did not report any QC results, it is possible that they were unaware of this over estimation. For the reminder of the results, data are in good agreement. Means varied from 1.03 to 2.16 µg kg-1. The calculated mean with Cofino model is 1.32±0.23 µg kg-1 using 40% of the dataset.

Figure 18 is extracted from the automatic report generated whilst running the BWE Cofino model, the graph on the left is the plot of the population density function, and the right hand graph shows the overlap matrix Kilt plot. The overlap integral is derived from the Cofino model. In this graph the lighter areas signify agreement while the black regions indicate no overlap of data. Laboratory 20 which is an extreme value has only black dot showing no agreement with other means, while the remaining laboratories shows fairly good agreement. The mean and standard deviation of the first mode is calculated as 1.41±0.40 µg kg-1, using 76% of the reported means.

Figure 18. Plot extracted of the automatic generated report of the

BWE Cofino model.

50

Although a bimodal distribution was not detected by the Cofino model, the data set was studied to try to evaluate any possible method bias. Such a bias may be caused by incomplete extraction of methyl mercury or the methylmercury may be overestimated as an artefact of the analytical process, as already reported extensively in the literature 21,22,23,24.Figure 19 classifies results by the sample preparation method used.

0

0.5

1

1.5

2

2.5

3

4 68 1 92b 20 26 32 65 36 83 92 93Laboratory Code

MeHg

conc

entra

tion n

g g-1

DistillationHNO3

Leaching+solvent extraction

Alkaline Digestion

+Solvent extraction

H2SO4/KBr/CuSO4 + Solvent extraction

GC-IDICP-MS

Cofino BWE Mean ± 1SD

Cofino Mean ± 1SD

out of scale 11.9Solvent

extractionSeparation

Org-Hg/Hg2+

CV-AAS

Acidic Thiourea LeachingLC-CV-

AFS

Figure 19. Reported means and sample preparation procedure. The 12 results reported are based on 7 distinct sample preparation methods. Only 3

methods were used by more than one participant: distillation, alkaline digestion and H2SO4/KBr/CuSO4 acid leaching followed by solvent extraction. However, none of the values reported using the common methodologies shows closer agreement than that existing within the rest of the data set. In conclusion, the distribution of the data could not be explained solely on the basis of the method, at least in the absence of very detailed description of procedures followed which might reveal differences within the methodologies used. It is possible that minor changes in the protocol might influence the results 22.

51

The calculated mean and standard deviation for the new BWE Cofino model is a good estimation of the consensus value as the relatively large standard deviation includes almost all reported means. It is for this reason that the BWE Cofino mean is preferred to the value calculated using first version of the Cofino model and this is the value reported on the reference sheet of IAEA 158.

To improve the uncertainty associated with this value, and maybe obtain a better estimate of the mean, it would be necessary to increase the number of reported values per techniques. The possible bias (high and low) arising from the sample preparation steps for different technique and that associated with the analytical procedure will also be scrutinised. The authors plan to run some of these experiments in Monaco and wish to start a collaborative work with some of the participants in order to get a better characterised value for MeHg in this material. Should this initiative be successful and result in a revised property value the work will be published in the scientific literature and participants to this interlaboratory comparison will be notified. 10. RECOMMENDATIONS

Participants are recommended to review their data element-by-element, appraising whether the Z-score is less than or equal to 2. The level of confidence required for data depends upon its final application (e.g., long-term trend data must be much more precise than data used for "hot spot" pollution monitoring). The use of the Z-scores will help identify systematic errors in accuracy (e.g. from calibration errors, reagent contamination or incomplete digestion) and should ultimately improve data quality.

Some laboratories still need to improve quality assurance / quality control procedures. Interlaboratory studies represent only one aspect of data quality assurance and can only provide occasional indicators of data reliability. Another valuable approach is through the regular analysis of certified reference materials, and by plotting the resulting data on a quality control chart. This provides continuous feedback to the analyst and is an essential tool for monitoring data quality and assuring acceptable results in future exercises.

Laboratories are encouraged to refer to IAEA reference methods in order to improve their analytical methods and their Quality Control procedures. These methods, listed on the website: http://www-naweb.iaea.org/naml/aqcsmethodes.asp are available free of charge from IAEA-MEL in Monaco. A full catalogue of available IAEA reference materials is published regularly and can be consulted on the IAEA website: http://www.iaea.org/programmes/aqcs

52

11. CONCLUSIONS The current intercomparison exercise for the determination of trace elements in

marine sediment attracted a large number of international participants. A consensus value could be given to 26 elements. In addition, information values were established for 15 elements including total mercury and methylmercury. Participants in the intercomparison should retain their samples as a Reference Material. The Reference Material is suitable to check the accuracy and precision of analytical measurements when sediment samples need to be analysed for trace elements.

IAEA-158 Reference Material is now available from the International Atomic Energy Agency (IAEA), AQCS, PO Box 100, A-1400 Vienna, Austria. 12. ACKNOWLEDGEMENTS

The authors wish to thank the participant laboratories in this intercomparison exercise listed in Appendix III, without whom this study would not have been possible. The Agency is grateful for the support provided to its Marine Environment Laboratories by the Government of the Principality of Monaco. This work was financially supported by the Inter-agency Programme on Marine Pollution agreed upon between UNEP and IAEA.

13. REFERENCES 1. Carvalho, F.P., The Inter-agency Programme on Marine Pollution. IAEA Bulletin,

1998. 40(3): p. 7-10. 2. Coquery, M., et al., The IAEA worldwide intercomparison exercises (1990-1997):

determination of trace elements in marine sediments and biological samples. The Science of the Total Environment, 1999. 237 / 238: p. 501-508.

3. Villeneuve, J.-P., S. de Mora, and C. Cattini, Determination of organochlorinated compounds and petroleum hydrocarbons in fish-homogenate sample IAEA-406: results from a worldwide interlaboratory study. TrAC Trends in Analytical Chemistry, 2004. 23(7): p. 501-510.

4. Villeneuve, J.-P., S.J. de Mora, and C. Cattini, World-Wide Intercomparison on the Determination of Chlorinated Pesticides, PCBs and Petroleum Hydrocarbons in Sediment Sample IAEA-417. Environmental Technology, 2002. 23: p. 1203-1217.

5. Wyse, E.J., et al., Characterization of Trace Elements and Methylmercury in an Estuarine Sediment Reference Material, IAEA-405. Journal of Environmental Monitoring, 2004. 6: p. 48-57.

53

6. Coquery, M., et al., Certification of trace and major elements and methylmercury concentrations in a macroalgae (Fucus sp.) reference material, IAEA-140. Fresenius Journal of Analytical Chemistry, 2000. 366: p. 792-801.

7. Horvat, M., et al., Certification of total mercury and methylmercury concentrations in mussel homogenate (Mytilus edulis) reference material, IAEA-142. Fresenius Journal of Analytical Chemistry, 1997. 358: p. 411-418.

8. Horvat, M., et al., Certification of methylmercury compounds concentration in marine sediment reference material, IAEA-356. Applied Organometallic Chemistry, 1994. 8: p. 533-540.

9. Ibe, A.C. and G. Kullenberg, Quality Assurance/Quality Control (QA/QC) regime in marine pollution monitoring programmes: the GIPME perspective. Marine Pollution Bulletin, 1995. 31(4-12): p. 209-213.

10. IAEA, Contaminant monitoring programmes using marine organisms: Quality Assurance and Good Laboratory Practice. Reference Methods for Marine Pollution Studies. 1990, IAEA.

11. Taylor, J.K., Quality assurance of chemical measurements. 1987, Boca Raton, FL, USA: Lewis Publishers Inc. 328.

12. Andersson, H.O.F., The rational use of proficiency tests and intercomparisons. Accreditation and Quality Assurance, 1998. 3(6): p. 224-226.

13. Cofino, W.P., et al., A new model for the inference of population characteristics from experimental data using uncertainties. Application to interlaboratory studies. Chemometrics and Intelligent Laboratory Systems, 2000. 53: p. 37-55.

14. Wells, D.E., Cofino, W.P. and Scurfield, J.A., The application of the Cofino model to evaluate laboratory performance study data using the bandwidth estimator. Fisheries research services collaborative report N°04/04. p71.

15. Wyse, E.J., S. Azemard, and S. de Mora, World-wide intercomparison exercise for the determination of trace elements and methylmercury in marine sediment IAEA-433. 2004, IAEA: Monaco. p. 113.

16. S. Azemard, S. de Mora, C. Guitart and Wyse, E.J, World-wide intercomparison exercise for the determination of trace elements and methylmercury in Tuna Fish Flesh Homogenate IAEA-436. 2006, IAEA: Monaco. p. 98.

17. Coquery, M., S. Azemard, and S. de Mora, Report on the world-wide intercomparison exercise for the determination of trace elements and methylmercury in estuarine sediment IAEA-405. 2000, IAEA: Monaco. p. 114.

18. ISO, Proficiency testing by interlaboratory comparisons, Part 1, ISO Guide 43-1. 1997, International Standardization Organisation: Geneva. p. 16.

54

19. Thompson, M. and R. Wood, The international harmonized protocol for the proficiency testing of (chemical) analytical laboratories IUPAC/ISO/AOAC. J. Pure.

20. IAEA, Reagent and laboratory-ware clean-up procedures for low-level contaminant monitoring. 1995, IAEA. p. 24.

21. Hintelmann, H., Comparison of different extraction techniques used for methymercury analysis with respect to accidental formation of methylmercury during sample preparation. Chemosphere, 1999. 39(7): p.1093-1105.

22. Hammerschimdt, C.R., Fitzgerald, W.F., Formation of artefact methylmercury during extraction from a sediment reference material. Analytical Chemistry, 2001. 73: p. 5930-5936.

23. Hintelmann, H., et al., Determination of artifactual formation of monomethylmercury (CH3Hg+) in environmental samples using Hg2+ isotopes with ICP-MS detection: Calculation of contents applying species specific isotope addition. Fresenius Journal of Analytical Chemistry, 1997. 358: p.363-370.

24. Liang, L., et al., Re-evaluation of distillation and comparison with HNO3 leaching/solvent extraction for isolation of methylmercury compounds from sediment/soil samples. Apllied organometallic chemistry, 2004. 18: p. 264-270.

55

APPENDIX I

DATA REPORT OF THE INDIVIDUAL LABORATORY RESULTS SORTED BY ELEMENT

IAEA-158

56

Aluminium (Al) (g kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates

Instrumental Technique

Digestion Code

Acid Code

Quality Control

2 17.8 3.9 6 E1 1 2 ERA540B 5 62 14.5 6 X1 0 0 IAEA-405 8 49.30 0.2 6 A1 1 1 QTM074MS 12 52.500 1.1 6 M1 1 1 IAEA-433 19 21.5 2.2 6 E1 1 2 20 55.0 2.2 6 A1 1 1 PACS-2 23 7.043 2.6 4 A1 3 2 27 48.9 5.3 3 M1 1 1 GBW 7310 28 53.944 0.1 6 X1 0 0 GBW07309 33 15.77 2.3 3 E1 3 2 35 44.300 7.4 6 N2 0 0 IAEA-405 42 18.571 12.6 6 ? 1 2 IAEA-405 44 57.0 5.4 6 A1 1 1 IAEA-433 46 48.6 1.6 6 A3 1 IAEA-433 50 12.084 1.4 6 E1 2 2 AGAL-10 51b 51.7 1.2 3 E1 4 SDO-1 51c 49.85319 1 X1 0 0 IAEA-433 52 50.387 4.4 6 E1 1 1 IAEA-405 53 54.0 1.9 6 M1 2 1 MESS-3 63 50.585 3.3 4 M1 1 1 MESS-3 65 48.8 0.7 6 E1 2 1 IAEA-405 69 15.775 8.8 3 A1 2 1 73 54.69 0.8 6 A1 2 1 MESS-3 78 47.97 0.8 6 N0 0 0 IAEA-405 82 45.077 3.2 6 M1 2 1 IAEA-433 90 311.27 3.1 6 X1 0 0 Antimony (Sb) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 0.18 27.8 6 M1 1 2 ERA540B 3b 1.71 3.5 6 N2 0 0 IAEA-433 12 1.32 7.6 6 M1 1 1 IAEA-433 20 1.6 6.3 5 A8 1 2 PACS-2 24 1.5 5.3 6 N2 0 0 SRM 2704 29 1.7 41.2 6 N2 0 0 IAEA-405 32 <10 E1 3 2 MESS-3 33 0.897 1.7 3 M1 3 2 35 1.34 10.4 6 N2 0 0 IAEA-405 48 1.37 13.9 6 N0 0 0 SRM2711 50 0.7 2.9 6 M1 2 2 AGAL-10 65 1.29 7.4 6 M1 2 1 IAEA-405 78 1.15 5.3 6 N0 0 0 IAEA-405 82 1.32 10.6 6 M1 2 1 IAEA-433 86 1.25 8.0 6 N2 0 0 Soil7

57

Arsenic (As) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 10.1 4.0 6 M1 1 2 ERA540B 3b 9.84 2.1 6 N2 0 0 IAEA-433 7 9.93 4.5 6 A4 3 1 IAEA-433 8 14.63 3.3 6 A4 1 1 QTM074MS 10 12.215 2.0 6 E1 3 2 11 10.73 7.7 3 E2 1 2 IMEP14 12 10.3 4.1 6 M1 1 1 IAEA-433 14 6.43 2.8 3 A8 1 2 15 12.7 7.1 6 A8 ? ? IAEA-405 17 18.5 5.5 6 A4 2 2 19 10.1 3.0 6 E1 1 2 20 11.2 5.4 6 A8 1 2 MESS-3 24 7.90 9.1 6 N2 0 0 SRM 2704 27 13.5 4.9 3 M1 1 1 GBW 7310 28 13.0 1.2 6 X1 0 0 GBW07309 29 7.2 18.1 6 N2 0 0 IAEA-405 30 11.6 2.2 6 A3 1 2 IAEA-433 31 9.5 11.6 3 A8 1 2 32 9.32 1.7 3 A8 3 2 MESS-3 33 9.45 5.5 3 E1 3 2 NO7004 35 8.24 10.7 6 N2 0 0 IAEA-405 36 13.4 22.4 6 A8 1 1 IAEA-433 39 12.7 4.7 3 E1 2 2 MESS-3 42 13.4 12.7 6 ? 1 2 IAEA-405 43 13.45 0.7 6 M1 1 2 LKSD4 44 13.0 5.4 6 A3 1 1 IAEA-433 45a 11.35 8.3 4 A8 1 1 IAEA-433 46 12.8 6.3 6 A3 1 IAEA-433 48 12.08 5.0 6 N0 0 0 SRM2711 49 14.2287 71.6 3 A8 2 1 IAEA-433 50 10.0 1.0 6 M1 2 2 AGAL-10 51a 12.4 9.3 3 A8 3 1 IAEA-433 52 23.4 3.4 3 E1 1 1 IAEA-405 55 10.7 7.1 6 A3 1 2 58 10.9 ? M1 1 2 61 10.600 7.5 6 E1 1 2 SRM-1646a 63 11.3 5.3 4 M1 1 2 MESS-3 64 11.9 2.5 6 M1 1 1 IAEA - SL-1 65 11.2 3.4 6 M1 2 1 IAEA-405 68 10.3 1.0 2 M1 2 2 NIST 2710 70 11.6 5.2 6 X1 0 0 DC 73307 72 5.26 41.4 6 A4 ? 1 73 12.08 2.1 6 A3 2 2 MESS-3 75 13.79 3.8 6 M1 1 1 SRM-1646a 78 11.32 4.5 6 N0 0 0 IAEA-405 82 13.19 3.3 6 M1 2 1 IAEA-433 83 13.07 9.6 6 M1 2 2 IAEA-433 86 11.8 5.1 6 N2 0 0 Soil7 87 9.8 14.3 6 N2 0 0 SRM1633A 92 11.7 2.6 6 A3 1 1 IAEA-433

58

Barium (Ba) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 581 4.1 6 M1 1 2 ERA540B 3c 1070 2.0 6 X1 0 0 IAEA-433 12 1120 1.1 6 M1 1 1 IAEA-433 28 750 1.5 6 X1 0 0 GBW07309 29 1039 4.0 6 N2 0 0 51c 900.481 0.0 1 X1 0 0 IAEA-433 82 1013 1.6 6 M1 2 1 IAEA-433 86 1005 3.4 6 N2 0 0 87 799 9.0 6 N2 0 0 SRM1633A Beryllium (Be) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 0.92 8.7 6 M1 1 2 ERA540B 12 1.97 2.2 6 M1 1 1 MESS-3 Boron (B) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 60.6 2.6 6 M1 1 2 ERA540B Bromine (Br) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

5 214 3.7 6 X1 0 0 IAEA-405 29 238 4.6 6 N2 0 0 IAEA-405 35 215.8 8.9 6 N2 0 0 48 222.7 0.9 6 N0 0 0 SRM2711 86 173 1.7 6 N2 0 0 Soil7 87 264 4.2 6 N2 0 0 3b 223 4.4 6 N2 0 0 IAEA-433

59

Cadmium (Cd) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 0.33 3.0 6 M1 1 2 ERA540B 3a 0.39 5.1 5 A1 3 2 IAEA-433 8 0.401 6.4 6 A4 1 1 QTM074MS 9 0.39 5.1 6 A4 2 2 10 1.070 2.1 6 E1 3 2 11 0.368 4.9 3 E1 1 2 IMEP14 12 0.395 1.5 6 M1 1 1 IAEA-433 15 0.33 6.1 6 A1 2 1 IAEA-405 17 0.320 7.8 6 A4 2 2 19 0.37 27.0 5 A3 1 2 20 0.383 3.1 6 A3 1 2 PACS-2 21 0.32 0.0 5 A1 3 2 22 0.362 0.0 6 M1 3 2 MESS-3 25 0.445 13.0 6 E1 2 2 SRM 2709 27 0.386 5.7 3 M1 1 1 GBW 7310 28 0.18 5.6 6 A4 3 2 GBW07309 30 0.34 2.9 6 A3 1 2 IAEA-433 31 0.314 4.1 3 A3 1 2 IAEA-433 32 0.43 3.3 3 M1 3 2 MESS-3 33 0.356 5.1 3 M1 3 2 NO7004 34 <0.0994 A1 1 1 36 0.580 20.9 6 A4 1 1 IAEA-433 37 <0.25 A1 2 2 38 <0.8 A1 2 2 IAEA-433 39 0.40 3.8 3 E1 2 2 MESS-3 40 0.44 9.1 6 M1 3 2 IAEA-433 42 0.227 22.0 6 ? 1 2 IAEA-405 43 0.408 5.9 6 M1 1 2 LKSD4 44 0.370 4.1 6 A3 1 1 IAEA-433 45a <0.001 P1 1 1 46 0.370 2.7 6 A3 1 IAEA-433 47 0.32 2.7 6 A4 2 1 BCSS-1 49 0.5850 4.3 3 A4 2 1 IAEA-433 50 0.4 7.5 6 M1 2 2 AGAL-10 51a <1 A3 3 1 SDO-1 53 0.38 2.6 6 M1 2 1 MESS-3 54 0.51 25.5 5 A3 3 1 GBW-07312 55 0.395 1.8 6 A3 1 2 57 0.28 7.1 3 A4 2 1 MESS-3 58 0.26 ? M1 1 2 60 0.339 3.2 3 A3 1 2 IAEA-433 61 0.535 5.2 6 E1 1 2 SRM-1646a 62 0.121 8.3 6 A6 1 2 IAEA-433 63 0.24 4.2 4 M1 1 2 MESS-3 64 0.345 2.6 5 M1 1 1 IAEA - SL-1 65 0.352 7.4 6 M1 2 1 IAEA-405 67 0.133 23.3 6 A4 1 1 IAEA-433 68 0.51 2.0 2 M1 2 2 NIST 2710 69 0.184 4.9 3 A1 2 1 70 0.8 62.5 6 X1 0 0 DC 73307 71 0.225 13.3 6 A4 1 1

60

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

72 <2.07 A1 ? 1 73 0.376 2.7 6 A3 2 1 MESS-3 74 0.479 2.6 6 A4 3 2 BCSS-1 75 0.43 2.3 6 M1 1 1 SRM-1646a 76 0.298 13.1 7 A4 2 2 77 0.503 5.6 5 A3 1 1 IAEA-405 78 0.33 6.1 5 A6 1 2 IAEA-405 79 0.3737 5.4 6 A3 1 1 IAEA-405 80 0.398 12.3 6 A1 3 2 MESS-3 81 0.257 3.9 6 A3 2 2 MESS-2 82 0.338 4.4 6 M1 2 1 IAEA-433 83 0.425 4.0 6 M1 2 2 IAEA-433 84 0.251 5.4 5 A4 3 1 IAEA-433 89 0.4427 6.0 6 A3 1 1 IAEA-433 92 0.363 4.7 6 A3 1 1 IAEA-433 Caesium (Cs) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

3b 3.90 5.1 6 N2 0 0 IAEA-433 12 3.97 0.8 6 M1 1 1 IAEA-433 29 3.9 12.8 6 N2 0 0 IAEA-405 35 3.65 4.9 6 N2 0 0 IAEA-405 48 3.707 0.7 6 N0 0 0 SRM2711 82 3.55 2.8 6 M1 2 1 IAEA-433 86 3.6 5.6 6 N2 0 0 Soil7 87 4.1 22.0 6 N2 0 0 SRM1633A Calcium (Ca) (g kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 61.8 2.6 6 E1 1 2 ERA540B 5 63.8 0.9 6 X1 0 0 IAEA-405 12 68.800 1.0 6 M1 1 1 MESS-3 28 88.270 0.1 6 X1 0 0 GBW07309 29 65.059 7.9 6 N2 0 0 51b 60.3 2.5 3 E1 4 SDO-1 51c 89.05 0.0 1 X1 0 0 IAEA-433 77 77.18 11.9 5 A1 1 1 IAEA-405 86 67 9.0 6 N2 0 0 87 19.2 6.8 6 N2 0 0 SRM1633A 91 40 5.0 ? A1 2 1

61

Cerium (Ce) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

3b 61.6 8.8 6 N2 0 0 IAEA-433 12 55.1 1.5 6 M1 1 1 IAEA-433 29 62.3 5.0 6 N2 0 0 35 63.0 6.0 6 N2 0 0 48 66.2 1.8 6 N0 0 0 SRM2711 78 56.68 1.5 6 N0 0 0 IAEA-405 82 51.3 5.5 6 M1 2 1 IAEA-433 86 64.1 0.9 6 N2 0 0 Soil7 87 59 15.3 6 N2 0 0 SRM1633A Chromium (Cr) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 49.3 3.9 6 M1 1 2 ERA540B 3b 73.1 1.7 6 N2 0 0 IAEA-433 3c 89 6.7 6 X1 0 0 IAEA-433 5 80 23.8 ? X1 0 0 IAEA-405 7 70.1 1.6 6 A2 3 1 IAEA-433 8 54.96 2.5 6 A1 1 1 QTM074MS 10 82.428 1.4 6 E1 3 2 12 78.5 2.1 6 M1 1 1 IAEA-433 14 84.6 4.8 3 X1 0 0 BCSS-1 15 70.2 2.4 6 A1 2 2 IAEA-405 17 46.4 1.3 6 A1 2 2 LGC-6137 18 61.83 3.4 4 A3 1 1 19 56.9 1.9 6 E1 1 2 20 66.1 2.6 6 A1 1 2 MESS-3 23 42.00 2.9 4 A1 3 2 24 83.2 3.6 6 N2 0 0 SRM 2704 25 74.4 0.9 6 E1 2 2 SRM 2709 27 73.4 3.8 3 M1 1 1 GBW 7310 28 88.6 1.9 6 X1 0 0 GBW07309 29 81.2 5.4 6 N2 0 0 IAEA-405 30 60.2 0.6 6 A3 1 2 IAEA-433 34 42.1912 5.1 6 A1 1 1 IAEA-405 35 74.0 5.3 6 N2 0 0 IAEA-405 36 179 10.6 6 A4 1 1 IAEA-433 38 59.33 5.7 3 A1 2 2 IAEA-433 39 43.0 1.2 3 E1 2 2 MESS-3 42 53.28 12.1 6 ? 1 2 IAEA-405 43 79.2 1.6 6 M1 1 2 LKSD4 44 77.8 3.7 6 A1 1 1 IAEA-433 45a 67.93 2.4 4 A1 1 1 IAEA-433 45b 62.7 5.9 6 N2 0 0 IAEA-433 46 77 3.9 6 A3 1 IAEA-433 47 89.99 4.2 6 A4 2 1 BCSS-1 48 85.2 2.1 6 N0 0 0 SRM2711 49 63.4338 31.2 3 A1 2 1 IAEA-433 50 45.9 1.1 6 ? 2 2 AGAL-10 51a 77 9.1 3 A3 3 1 SDO-1

62

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

51c 132.844 0.0 1 X1 0 0 IAEA-433 52 70.6 1.6 6 E1 1 1 IAEA-405 53 75 5.3 6 M1 2 1 MESS-3 54 69.45 13.0 5 A3 3 1 GBW-07312 55 40.7 1.8 6 A1 1 2 56 61.01 1.8 6 A1 1 1 IAEA-433 57 77.06 2.6 3 A1 2 1 MESS-3 58 49.1 ? M1 1 2 59 87.9 1.9 3 A1 3 2 60 60.12 5.2 3 A3 1 2 IAEA-433 61 48.033 2.8 6 E1 1 2 SRM-1646a 62 68.4 5.4 6 A6 1 2 IAEA-433 63 96.4 2.8 4 M1 1 1 MESS-3 64 74.2 2.3 6 M1 1 1 IAEA - SL-1 65 64.4 1.7 6 M1 2 1 IAEA-405 68 71 4.6 2 M1 2 2 NIST 2710 69 37.9 7.1 3 A1 2 1 70 83 3.0 6 X1 0 0 DC 73307 71 67.85 2.4 6 A1 1 1 IAEA-433 73 72.69 4.0 6 A3 2 1 MESS-3 75 78.2 0.6 6 M1 1 1 SRM-1646a 76 84.327 4.2 7 A1 2 2 78 77.08 2.2 6 N0 0 0 IAEA-405 79 54.658 6.4 6 A3 1 1 IAEA-405 82 71.4 2.7 6 M1 2 1 IAEA-433 83 65.5 3.3 6 E1 2 1 IAEA-433 84 68.78 2.3 6 A1 3 1 IAEA-433 85 81.4 0.9 3 E0 1 1 IAEA-433 86 79 5.1 6 N2 0 0 Soil7 87 73 6.8 6 N2 0 0 SRM1633A 88 72.8 2.6 5 A3 2 1 MESS-3 89 73.8 4.5 6 A1 1 1 IAEA-433 90 135 15.6 6 X1 0 0 92 80.2 1.6 6 A3 1 1 IAEA-433 Cobalt (Co) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 7.75 2.7 6 M1 1 2 ERA540B 3b 8.73 0.9 6 N2 0 0 IAEA-433 7 10.5 4.9 6 A4 3 1 IAEA-433 10 10.881 1.6 6 E1 3 2 11 9.15 0.3 3 E1 1 2 IMEP14 12 9.76 1.8 6 M1 1 1 IAEA-433 14 7.51 4.8 3 X1 0 0 BCSS-1 19 10.5 1.3 6 E1 1 2 20 8.0 3.8 6 A1 1 2 MESS-3 22 9.54 0.0 6 M1 3 2 MESS-3 23 3.58 9.5 4 A1 3 2 24 9.85 5.1 6 N2 0 0 SRM 2704 28 9.32 30.0 6 X1 0 0 GBW07309

63

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

29 9.8 8.2 6 N2 0 0 IAEA-405 31 8.4 6.0 3 A3 1 2 IAEA-433 33 8.18 5.0 3 E1 3 2 NO7004 34 7.664 6.3 6 A1 1 1 IAEA-405 35 8.87 6.7 6 N2 0 0 IAEA-405 37 14.9 18.3 5 A1 2 2 SD-M-2/TM 39 6.8 0.9 3 E1 2 2 MESS-3 40 6.97 1.9 6 E1 3 2 IAEA-433 42 15.93 11.2 6 ? 1 2 IAEA-405 43 9.76 6.0 5 A1 1 2 LKSD4 44 9.13 1.4 6 A3 1 1 IAEA-433 45a 10.59 6.1 4 A1 1 1 IAEA-433 45b 9.1 3.3 6 N2 0 0 IAEA-433 46 9.7 2.1 6 A3 1 IAEA-433 48 9.095 0.7 6 N0 0 0 SRM2711 50 5.7 1.8 6 M1 2 2 AGAL-10 51a 7.7 19.5 3 A3 3 1 SDO-1 52 11.4 3.5 6 E1 1 1 IAEA-405 53 8.5 4.7 4 A6 2 1 MESS-3 54 11.2 10.7 3 A3 3 1 GBW-07312 61 8.233 2.8 6 E1 1 2 SRM-1646a 63 8.54 1.3 4 M1 1 2 MESS-3 64 9.92 1.6 5 M1 1 1 IAEA - SL-1 65 9.71 2.1 6 M1 2 1 IAEA-405 68 8.4 2 M1 2 2 NIST 2710 70 11.5 8.7 6 X1 0 0 72 8.04 27.7 6 A1 ? 1 74 5.595 3.0 6 A1 3 2 BCSS-1 75 9.33 2.3 6 M1 1 1 SRM-1646a 78 8.92 1.1 6 N0 0 0 IAEA-405 79 6.552 3.8 6 A3 1 1 IAEA-405 82 9.07 2.0 6 M1 2 1 IAEA-433 83 11.3 5.1 6 E1 2 1 IAEA-433 85 7.65 0.9 3 E0 1 1 IAEA-433 86 9.6 2.1 6 N2 0 0 Soil7 87 8.5 14.1 6 N2 0 0 SRM1633A 90 138 11.6 6 X1 0 0 92 8.3 1.2 6 A3 1 1 IAEA-433

64

Copper (Cu) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 46.7 6.2 6 M1 1 2 ERA540B 3a 49 8.2 6 A1 3 2 IAEA-433 3c 45 4.4 6 X1 0 0 IAEA-433 5 75 24.0 ? X1 0 0 IAEA-405 7 52.5 4.0 6 A4 3 1 IAEA-433 8 51.86 4.4 6 A1 1 1 QTM074MS 9 43.43 6.6 5 A4 2 2 IAEA-436 10 42.970 2.4 6 E1 3 2 11 53.6 5.0 3 E1 1 2 IMEP14 12 50.4 6.8 6 M1 1 1 IAEA-433 13 59.46 0.7 6 A1 1 1 MESS-3 14 40.5 8.1 3 X1 0 0 BCSS-1 15 48.3 4.6 6 A1 2 1 IAEA-405 16 46.392 8.9 6 A1 1 1 HPS-830702 17 48.8 0.8 6 A1 2 2 LGC-6137 18 37.48 7.1 4 A3 1 1 19 51.2 3.5 6 E1 1 2 20 48.0 2.3 4 A1 1 2 MESS-3 21 44.6 0.0 3 A1 3 2 22 46.6 0.0 6 A1 3 2 MESS-3 23 43.34 4.5 4 A1 3 2 25 49.9 6.6 6 E1 2 2 SRM 2709 27 56.7 7.6 3 M1 1 1 GBW 7310 28 50.6 1.2 6 X1 0 0 GBW07309 30 45.1 2.0 5 A1 1 2 IAEA-433 31 42.7 3.5 3 A3 1 2 IAEA-433 32 55.4 0.3 3 E1 3 2 MESS-3 33 49.1 1.7 3 E1 3 2 NO7004 34 31.2179 7.0 6 A1 1 1 IAEA-405 36 33.2 12.3 6 A4 1 1 IAEA-433 37 54.4 18.4 5 A1 2 2 SD-M-2/TM 38 50.6 4.4 3 A1 2 2 IAEA-433 39 46.1 9.1 3 E1 2 2 MESS-3 40 39.4 1.5 6 E1 3 2 IAEA-433 42 45.42 19.7 6 ? 1 2 IAEA-405 43 42.6 6.1 6 M1 1 2 LKSD4 44 44.2 2.9 6 A3 1 1 IAEA-433 45a 50.74 11.3 4 A1 1 1 IAEA-433 45c 48.2 5.0 6 X1 0 0 IAEA-433 46 47.0 4.5 6 A3 1 IAEA-433 47 48.21 8.6 6 A4 2 1 BCSS-1 49 47.1653 10.0 3 A1 2 1 IAEA-433 50 51.3 2.3 6 ? 2 2 AGAL-10 51a 56 7.1 3 A3 3 1 SDO-1 51c 50.42 0.0 1 X1 0 0 IAEA-433 52 49.4 6.9 6 E1 1 1 IAEA-405 53 43.5 8.3 6 M1 2 1 MESS-3 54 48 13.8 6 A3 3 1 GBW-07312 55 49.2 2.0 6 A1 1 2 56 30.58 0.9 6 A1 1 1 IAEA-433 57 51.37 12.4 3 A1 2 1 MESS-3 58 42.8 ? M1 1 2 59 51.6 8.5 3 A1 3 2 IAEA-433 60 43.61 1.5 3 A3 1 2 IAEA-433

65

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

61 59.150 4.0 6 E1 1 2 SRM-1646a 62 58.10 1.1 6 A1 1 2 IAEA-433 63 43.9 7.1 4 M1 1 2 MESS-3 64 46.8 3.2 4 M1 1 1 IAEA - SL-1 65 49.1 6.6 6 M1 2 1 IAEA-405 66 51.6 16.1 3 A0 2 2 IAEA-405 67 28.5 6.0 6 A1 1 1 IAEA-433 68 52.5 11.0 2 M1 2 2 NIST 2710 69 85.99 3.2 3 A1 2 1 70 53 7.5 6 X1 0 0 DC 73307 71 52.25 4.4 6 A1 1 1 IAEA-433 72 48.09 21.7 6 A1 ? 1 73a 48.7 3.5 5 A1 2 2 MESS-3 73b 52.1 4.5 5 A1 2 1 MESS-3 74 42.587 2.3 6 A1 3 2 BCSS-1 75 46.5 3.9 5 M1 1 1 SRM-1646a 76 35.017 5.7 7 A1 2 2 78 49.3 3.2 5 A1 1 2 IAEA-405 80 45.77 2.3 6 A1 3 2 MESS-3 81 37.55 4.5 6 A1 2 2 MESS-2 82 47.7 7.3 6 M1 2 1 IAEA-433 83 45.6 5.7 6 E1 2 1 IAEA-433 84 47.92 2.0 6 A1 3 1 IAEA-433 85 21.2 1.2 3 E0 1 1 IAEA-433 88 52.9 3.0 4 A3 2 1 MESS-3 89 54.7 2.4 6 A1 1 1 IAEA-433 90 36 8.3 6 X1 0 0 91 43 2.3 ? A1 2 1 92 46.4 5.8 6 A1 1 1 IAEA-433 Europium (Eu) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

12 1.10 1.5 6 M1 1 1 IAEA-433 24 1.094 5.3 6 N2 0 0 SRM 2704 29 1.07 4.7 6 N2 0 0 IAEA-405 35 0.97 9.3 6 N2 0 0 IAEA-405 48 0.998 3.1 6 N0 0 0 SRM2711 82 1.173 2.2 6 M1 2 1 IAEA-433 86 1.09 1.8 6 N2 0 0 Soil7

66

Hafnium (Hf) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

12 4.36 4.6 6 M1 1 1 IAEA-433 24 6.44 6.1 6 N2 0 0 SRM 2704 29 6.37 4.9 6 N2 0 0 IAEA-405 35 5.7 3.5 6 N2 0 0 IAEA-405 48 6.30 5.6 6 N0 0 0 SRM2711 86 6.3 3.2 6 N2 0 0 87 4.5 15.6 6 N2 0 0 SRM1633A Iron (Fe) (g kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 23 2.7 6 E1 1 2 ERA540B 3b 28.3 1.1 6 N2 0 0 IAEA-433 3c 26.5 0.8 6 X1 0 0 IAEA-433 5 27.010 0.8 6 X1 0 0 IAEA-405 7 26.1 2.6 6 E1 3 1 IAEA-433 8 28.00 0.8 6 A1 1 1 QTM074MS 9 10.110 2.1 5 A1 2 2 IAEA-436 10 32.053200 0.1 6 E1 3 2 11 27.100 1.8 3 E1 1 2 IMEP14 12 26.200 1.9 6 M1 1 1 IAEA-433 13 27.352 1.4 6 A1 1 1 MESS-3 15 31.016 0.7 6 T 2 2 IAEA-405 17 23.072 0.2 6 A1 2 2 LGC-6137 18 26.179 2.4 4 A1 1 1 19 24.5 1.0 6 E1 1 2 20 26.3 1.1 6 A1 1 2 PACS-2 21 21.8 0.0 5 A1 3 2 23 16.71871 2.5 4 A1 3 2 24 27.417 4.1 6 N2 0 0 SRM 2704 27 27.7 6.9 3 M1 1 1 GBW 7310 28 29.208 0.1 6 X1 0 0 GBW07309 29 28.01 0.5 6 N2 0 0 IAEA-405 30 25.946 0.8 5 A1 1 2 IAEA-433 33 23.2 1.4 3 E1 3 2 34 12.999 4.4 6 A1 1 1 IAEA-405 35 26.080 4.2 6 N2 0 0 IAEA-405 37 16.1 8.7 5 A1 2 2 SD-M-2/TM 39 20.8 0.7 3 E1 2 2 MESS-3 42 22.520 12.1 6 ? 1 2 IAEA-405 43 23.376 4.8 6 A1 1 2 LKSD4 44 25.4 4.3 6 A1 1 1 IAEA-433 45a 24.13 4.6 4 A1 1 1 IAEA-433 45b 24.962 3.3 6 N2 0 0 IAEA-433 45c 25.381 3.7 6 X1 0 0 IAEA-433 46 23.4 2.6 6 A3 1 IAEA-433 48 26.580 0.7 6 N0 0 0 SRM2711 50 23.005 1.4 6 E1 2 2 AGAL-10 51b 26 3.8 3 E1 4 SDO-1

67

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

51c 28.9481162 0.0 1 X1 0 0 IAEA-433 52 26.6213 1.1 3 E1 1 1 IAEA-405 53 28.3 3.5 6 M1 2 1 MESS-3 54 22.67 9.4 5 A1 3 1 55 19.852 2.8 6 A1 1 2 56 27.84 2.4 6 A1 1 1 IAEA-433 57 28.7 1.0 3 A1 2 1 MESS-3 59 25.993 1.4 3 A1 3 2 IAEA-433 61 19.787 7.1 6 E1 1 2 SRM-1646a 62 25.740 0.9 6 A1 1 2 IAEA-433 63 24.600 0.9 4 M1 1 2 MESS-3 65 27.1 1.4 6 E1 2 1 IAEA-405 66 23.156 2.6 3 A0 2 2 IAEA-405 68 24.2 2.1 2 M1 2 2 NIST 2710 69 14.129 5.3 3 A1 2 1 70 26.925 0.4 6 X1 0 0 DC 73307 71 35.756 4.8 5 A1 1 1 IAEA-433 73 28.98 1.4 6 A1 2 1 MESS-3 74 29.6 0.3 6 X1 0 0 BCSS-1 77 28.243 7.1 5 A1 1 1 IAEA-405 78 25.86 1.4 6 N0 0 0 IAEA-405 80 26.185 1.7 6 A1 3 2 MESS-3 82 29.608 1.8 6 M1 2 1 IAEA-433 84 26.27 2.1 6 A1 3 1 IAEA-433 85 11.7 2.7 3 E0 1 1 IAEA-433 86 27 3.7 6 N2 0 0 Soil7 87 24.9 5.2 6 N2 0 0 SRM1633A 90 19.66 5.7 6 X1 0 0 91 24.8 3.2 ? A1 2 1 92 27.6 2.9 6 A1 1 1 IAEA-433 Lanthanum (La) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

3b 31.8 6.2 6 N2 0 0 IAEA-433 12 29.8 1.7 6 M1 1 1 IAEA-433 24 33.4 4.2 6 N2 0 0 SRM 2704 29 31.3 4.5 6 N2 0 0 IAEA-405 35 28.6 8.7 6 N2 0 0 IAEA-405 48 30.35 2.7 6 N0 0 0 SRM2711 78 29.06 4.0 6 N0 0 0 IAEA-405 82 26.1 5.7 6 M1 2 1 IAEA-433 86 28.9 1.0 6 N2 0 0 Soil7 87 32 15.6 6 N2 0 0 SRM1633A

68

Lead (Pb) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 36.8 2.4 6 M1 1 2 ERA540B 3a 43 4.7 6 A1 3 2 IAEA-433 3c 38 7.9 6 X1 0 0 IAEA-433 5 96 21.9 ? X1 0 0 IAEA-405 7 39.6 8.8 6 A4 3 1 IAEA-433 8 44.55 4.3 6 A4 1 1 QTM074MS 9 29.96 4.3 6 A4 2 2 10 54.042 2.4 6 E1 3 2 12 42.4 2.3 6 M1 1 1 IAEA-433 13 30.70 2.7 6 A1 1 1 MESS-3 14 26.1 10.3 3 E1 1 2 15 39.1 4.6 6 A1 2 1 IAEA-405 17 35.7 0.6 6 A1 2 2 LGC-6137 18 36.85 6.4 4 A3 1 1 19 34.5 5.5 6 E1 1 2 20 39.0 1.5 6 A1 1 2 MESS-3 21 36.7 0.0 3 A1 3 2 22 39.5 0.0 6 M1 3 2 MESS-3 23 29.70 5.3 4 A1 3 2 25 40.5 9.9 6 E1 2 2 SRM 2709 27 37.9 1.7 3 M1 1 1 GBW 7310 28 46.6 3.9 6 X1 0 0 GBW07309 30 38.6 6.5 6 A3 1 2 IAEA-433 31 32.4 4.9 3 A3 1 2 IAEA-433 32 40.1 0.7 3 M1 3 2 MESS-3 33 35.4 1.7 3 E1 3 2 NO7004 34 15.6574 6.6 6 A1 1 1 IAEA-405 36 41.6 16.3 6 A4 1 1 IAEA-433 37 31.2 10.7 5 A1 2 2 SD-M-2/TM 38 47.47 7.0 3 A1 2 2 IAEA-433 39 32 3.1 3 E1 2 2 MESS-3 40 32.2 2.6 6 E1 3 2 IAEA-433 42 42.5 13.9 6 ? 1 2 IAEA-405 43 36.4 4.7 6 M1 1 2 LKSD4 44 40.0 1.3 6 A3 1 1 IAEA-433 45a 33.30 12.6 4 A1 1 1 IAEA-433 46 40.0 2.8 6 A3 1 IAEA-433 47 50.90 1.8 6 A4 2 1 BCSS-1 49 41.8509 21.6 3 A4 2 1 IAEA-433 50 38.4 5.2 6 ? 2 2 AGAL-10 51a 51 5.9 3 A3 3 1 SDO-1 52 37.9 5.0 6 E1 1 1 IAEA-405 53 43.9 9.1 6 M1 2 1 MESS-3 54 51.81 11.3 6 A3 3 1 GBW-07312 55 40.0 1.4 6 A3 1 2 58 37.0 ? M1 1 2 59 42.4 4.5 3 A1 3 2 IAEA-433 60 32.41 5.3 3 A3 1 2 IAEA-433 61 39.867 3.9 6 E1 1 2 SRM-1646a 62 26.68 7.0 6 A6 1 2 IAEA-433 63 31.5 6.7 4 M1 1 2 MESS-3

69

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

64 39.4 2.5 4 M1 1 1 IAEA - SL-1 65 44.8 3.5 6 M1 2 1 IAEA-405 66 58.6 11.9 3 A0 2 2 IAEA-405 67 48.58 9.4 6 A4 1 1 IAEA-433 68 46.7 0.4 2 M1 2 2 NIST 2710 69 20.47 12.9 3 A1 2 1 70 45 2.2 6 X1 0 0 DC 73307 71 48.91 3.0 6 A1 1 1 IAEA-433 73a 40.3 3.9 5 A3 2 1 MESS-3 73b 44.9 3.4 5 A3 2 2 MESS-3 74 26.56 4.0 6 A1 3 2 BCSS-1 75 52.5 3.4 6 M1 1 1 SRM-1646a 77 30.162 13.7 5 A3 1 1 IAEA-405 78 33.7 10.7 5 A6 1 2 IAEA-405 79 44.513 10.6 6 A3 1 1 IAEA-405 80 35.3 3.3 6 A1 3 2 MESS-3 81 17.5 6.3 5 A1 2 2 MESS-2 82 43.2 4.4 6 M1 2 1 IAEA-433 83 33.9 6.3 6 M1 2 2 IAEA-433 84 42.25 4.0 6 A4 3 1 IAEA-433 85 26.6 1.2 3 E0 1 1 IAEA-433 88 96 2.3 5 A3 2 1 MESS-3 89 28.5 13.3 6 A3 1 1 IAEA-433 92 43.1 6.0 6 A3 1 1 IAEA-433 Lithium (Li) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 26.3 1.9 6 M1 1 2 ERA540B 8 19.45 1.5 6 A1 1 1 QTM074MS 12 35.9 1.4 6 M1 1 1 IAEA-433 19 30 2.0 6 A1 1 2 20 28.8 1.0 6 A1 1 2 PACS-2 27 35.7 5.9 3 M1 1 1 GBW 7310 45a 25.95 11.0 4 A1 1 1 IAEA-433 52 41.9 6.2 6 E1 1 1 IAEA-405 53 31 6.5 6 M1 2 1 MESS-3 63 30.0 0.7 4 M1 1 2 MESS-3 82 27.01 1.9 6 M1 2 1 IAEA-433 83 34.9 4.7 6 E1 2 1 IAEA-433 Lutetium (Lu) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

24 0.348 6.3 6 N2 0 0 SRM 2704 29 0.304 72.7 6 N2 0 0 IAEA-405 35 0.28 10.7 6 N2 0 0 IAEA-405 86 0.31 9.7 6 N2 0 0 Soil7 87 0.296 11.1 6 N2 0 0 SRM1633A

70

Magnesium (Mg) (g kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 8.64 2.2 6 E1 1 2 ERA540B 9 4.014 3.6 5 A1 2 2 IAEA-436 12 11.600 1.3 6 M1 1 1 IAEA-433 28 15.727 0.2 6 X1 0 0 GBW07309 30 10.247 0.7 6 A1 1 2 IAEA-433 43 0.77 3.6 6 M1 1 2 LKSD4 50 10.167 0.8 6 E1 2 2 AGAL-10 51b 16.4 5.5 3 E1 4 SDO-1 51c 13.932 0.0 1 X1 0 0 IAEA-433 52 8.4481 2.8 6 E1 1 1 IAEA-405 63 13.5 2.7 4 M1 1 1 MESS-3 65 11.0 1.1 6 E1 2 1 IAEA-405 77 11.214 12.9 5 A1 1 1 IAEA-405 78 10.64 3.9 6 N0 0 0 IAEA-405 82 9.598 5.3 6 M1 2 1 IAEA-433 Manganese (Mn) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 247 2.4 6 E1 1 2 ERA540B 3a 360 4.7 6 A1 3 2 IAEA-433 3c 316 2.5 6 X1 0 0 IAEA-433 5 332 9.9 6 X1 0 0 IAEA-405 7 395 0.9 6 A1 3 1 IAEA-433 8 376.6 1.2 6 A1 1 1 QTM074MS 10 326.687 0.3 6 E1 3 2 11 316 1.6 3 E1 1 2 IMEP14 12 383 1.6 6 M1 1 1 IAEA-433 13 355.88 0.1 6 A1 1 1 MESS-3 14 353 5.2 3 X1 0 0 BCSS-1 15 328 0.9 6 A1 2 1 IAEA-405 17 257.3 1.4 6 A1 2 2 LGC-6137 18 373 4.3 4 A1 1 1 19 318 1.4 6 E1 1 2 20 369 2.2 6 A1 1 2 PACS-2 21 251.0 0.0 5 A1 3 2 22 268 0.0 6 A1 3 2 MESS-3 24 362.8 2.9 6 N2 0 0 SRM 2704 27 408 6.1 3 M1 1 1 GBW 7310 28 332 0.9 6 X1 0 0 GBW07309 29 337 2.7 6 N2 0 0 IAEA-405 30 337 1.1 6 A1 1 2 IAEA-433 31 259 6.2 3 A3 1 2 IAEA-433 33 280 3.4 3 E1 3 2 34 152.6428 7.0 6 A1 1 1 IAEA-405 35 331.5 12.9 6 N2 0 0 IAEA-405 37 235 2.8 5 A1 2 2 SD-M-2/TM 38 270.3 2.3 2 A1 2 2 IAEA-433 39 245 0.4 3 E1 2 2 MESS-3 40 220 3.0 6 E1 3 2 IAEA-433

71

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

42 288 12.0 6 ? 1 2 IAEA-405 43 305 3.0 6 A1 1 2 LKSD4 44 360 1.9 6 A1 1 1 IAEA-433 45a 372.90 4.4 4 A1 1 1 IAEA-433 45c 324.5 4.6 6 X1 0 0 IAEA-433 46 358 1.4 6 A3 1 IAEA-433 49 339.303 4.6 3 A1 2 1 IAEA-433 50 251.0 1.4 6 ? 2 2 AGAL-10 51b 362 4.1 3 E1 4 SDO-1 51c 394.9 0.0 1 X1 0 0 IAEA-433 52 365.0 1.5 6 E1 1 1 IAEA-405 53 359 3.3 6 M1 2 1 MESS-3 55 341.7 0.3 6 A1 1 2 56 376.26 0.7 6 A1 1 1 IAEA-433 57 386.8 0.5 3 A4 2 1 MESS-3 59 389 0.5 3 A1 3 2 IAEA-433 61 261.0 3.8 6 E1 1 2 SRM-1646a 62 335 0.4 6 A1 1 2 IAEA-433 63 365 2.2 4 M1 1 1 MESS-3 65 348 1.4 6 E1 2 1 IAEA-405 66 286.1 6.5 3 A0 2 2 IAEA-405 68 370 3.0 2 M1 2 2 NIST 2710 69 221.8 2.3 3 A1 2 1 70 360 1.1 6 X1 0 0 DC 73307 71 367.35 1.2 5 A1 1 1 IAEA-433 73 372.6 1.3 6 A1 2 1 MESS-3 74 341.67 5.7 6 X1 0 0 BCSS-1 75 382.8 1.4 6 M1 1 1 SRM-1646a 76 239.263 10.7 7 A1 2 2 77 377 2.4 5 A1 1 1 IAEA-405 78 340 2.4 6 N0 0 0 IAEA-405 80 322.1 1.7 6 A1 3 2 MESS-3 82 397.9 2.5 6 M1 2 1 IAEA-433 83 311 2.8 6 E1 2 1 IAEA-433 84 336.35 2.3 6 A1 3 1 IAEA-433 85 233 2.4 3 E0 1 1 IAEA-433 89 354 5.2 6 A1 1 1 IAEA-433 90 400 8.8 6 X1 0 0 91 308 0.6 ? A1 2 1 92 337 2.4 6 A1 1 1 IAEA-433 Mercury (Hg) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

1 0.127 7.9 17 F1 3 2 IAEA-405 2 0.11 9.1 6 A7 1 2 ERA540B 3a 0.14 7.1 5 A7 3 2 IAEA-433 4 0.1349 7.9 9 M3 2 2 MESS-3 6 0.119 6.7 6 A9 0 0 ERA540 7 0.069 10.1 6 A7 3 2 IAEA-433 8 0.159 11.3 6 A7 1 1 QTM074MS 10 0.328 2.1 6 E1 3 2

72

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

11 0.172 7.0 3 E2 1 2 IMEP14 12 0.159 3.8 6 M1 1 2 IAEA-433 14 0.133 3.8 3 A9 0 0 15 0.13 7.7 6 A7 2 2 IAEA-405 17 0.124 3.2 6 A7 2 2 LGC-6137 18 0.23 4.3 3 A7 1 1 19 0.19 10.5 5 A7 1 2 20 0.130 6.2 5 F1 1 2 PACS-2 21 0.18 0.0 6 F1 3 2 26 0.129 3.0 6 F1 2 2 MESS-2 27 0.152 21.1 3 M1 1 1 GBW 7310 28 0.306 3.3 3 A7 3 2 GBW07309 31 0.118 4.2 6 A9 0 0 IAEA-433 32 0.151 0.9 3 F1 3 2 MESS-3 33 0.144 5.6 3 A9 0 0 NO7004 34 0.0682 30.9 6 A7 1 1 IAEA-405 36 0.102 33.3 6 A7 1 1 IAEA-433 39 0.127 5.5 3 A7 2 2 MESS-3 40 0.102 6.9 6 A7 3 2 IAEA-433 41 0.1407 7.1 4 A7 1 2 IAEA-433 42 0.0667 7.3 6 A7 1 2 IAEA-405 43 0.338 5.6 5 M1 1 2 44 0.132 6.1 6 A7 1 2 IAEA-433 45a 0.77 17.5 4 A7 1 1 IAEA-433 47 0.122 4.1 6 A7 2 1 BCSS-1 50 0.1 10.0 6 M1 2 2 AGAL-10 51a 0.262 5.3 3 A7 2 2 IAEA-433 53 0.133 6.0 6 A9 0 1 MESS-3 55 0.121 0.8 6 A9 0 2 58 0.17 ? A8 1 2 60 0.109 5.5 3 A7 1 2 IAEA-433 61 <0.2 A7 1 2 63 0.144 6.3 4 A7 1 2 65 0.167 17.4 6 A7 2 1 IAEA-405 67 2.36 7.2 6 A7 1 1 IAEA-433 68 0.124 3.4 2 F1 2 2 MESS-3 71 0.099 3.0 5 A7 1 1 IAEA-433 73 0.1438 7.1 6 A7 2 2 MESS-3 76 0.144 11.1 7 A7 2 2 77 0.279 9.3 6 A7 1 1 IAEA-405 80 0.1298 6.2 6 A7 3 2 MESS-3 83 0.11 9.1 6 A9 0 0 IAEA-433 84 0.144 48.6 6 A7 3 2 IAEA-433 86 0.0727 7.2 6 A7 2 2 88 0.135 1.5 6 A9 0 0 MESS-3 92 0.131 6.9 6 A9 0 0 MESS-2

73

Methyl mercury (MeHg) (µg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

1 1.18 5.9 13 IAEA-405 4 1.79 2.8 7 IAEA-405 20 11.9 15.1 4 26 1.3 6.2 6 IAEA 405 32 2.16 7.2 6 IAEA-405 36 1.1 21.8 6 IAEA-433 65 1.53 3.8 6 IAEA-405 68 1.13 0.9 2 CRM 580 83 1.03 13.6 6 IAEA-433 92 1.41 8.9 4 IAEA-405 92b 1.65 3.6 3

See detail in table

IAEA-405 Molybdenum (Mo) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 3.73 5.1 6 M1 1 2 ERA540B 12 4.97 5.0 6 M1 1 1 MESS-3 29 7.3 23.3 6 N2 0 0 51a 4.7 12.8 3 A3 3 1 SDO-1 51c 4.74 0.0 1 X1 0 0 IAEA-433 87 5.1 15.7 6 N2 0 0 Neodymium (Nd) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

12 26.4 1.3 6 M1 1 1 IAEA-433 29 27.4 6.9 6 N2 0 0 35 31.0 9.7 6 N2 0 0 82 22.9 4.8 6 M1 2 1 IAEA-433 86 37 5.4 6 N2 0 0 Soil7 87 21 23.8 6 N2 0 0 SRM1633A Nickel (Ni) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 27.0 2.6 6 M1 1 2 ERA540B 3a 26 8.8 6 A1 3 2 IAEA-433 3c 30 6.7 6 X1 0 0 IAEA-433 5 42 52.4 ? X1 0 0 8 33.26 1.1 6 A4 1 1 QTM074MS 10 35.025 4.2 6 E1 3 2 11 27 0.7 3 E1 1 2 IMEP14 12 31.5 1.2 6 M1 1 1 IAEA-433 13 21.18 0.02 6 A1 1 1 MESS-3 14 30.3 2.7 3 X1 0 0 BCSS-1 15 29.9 2.3 6 A1 2 1 IAEA-405 17 26.2 1.6 6 A1 2 2 LGC-6137 18 26.09 11.2 4 A3 1 1

74

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

19 27.5 1.5 6 E1 1 2 20 30.0 1.3 6 A1 1 2 MESS-3 22 33.3 0.0 6 A1 3 2 MESS-3 23 24.34 2.3 4 A1 3 2 27 34.4 4.9 3 M1 1 1 GBW 7310 28 44.3 1.7 6 X1 0 0 GBW07309 30 30.3 4.3 6 A3 1 2 IAEA-433 31 31.4 2.9 3 A3 1 2 IAEA-433 33 25.1 5.0 3 E1 3 2 NO7004 34 10.9069 4.2 6 A1 1 1 IAEA-405 37 29.2 11.6 5 A1 2 2 SD-M-2/TM 38 23.43 5.2 3 A1 2 2 IAEA-433 39 24.5 0.5 3 E1 2 2 MESS-3 40 22.2 2.4 6 E1 3 2 IAEA-433 42 28.32 13.8 6 ? 1 2 IAEA-405 43 22.2 2.3 6 M1 1 2 LKSD4 44 28.5 3.2 6 A3 1 1 IAEA-433 45a 30.79 18.7 4 A1 1 1 IAEA-433 46 28.5 3.2 6 A3 1 IAEA-433 49 32.2600 23.1 3 A1 2 1 IAEA-433 50 27.0 2.6 6 ? 2 2 AGAL-10 51a 39 7.7 3 A3 3 1 SDO-1 51c 35.04 0.0 1 X1 0 0 IAEA-433 52 33.5 4.2 6 E1 1 1 IAEA-405 53 31.8 6.3 6 M1 2 1 MESS-3 55 37.1 0.8 6 A1 1 2 56 39.37 1.1 6 A1 1 1 IAEA-433 59 35.3 3.7 3 A1 3 2 IAEA-433 60 32.86 3.2 3 A1 1 2 IAEA-433 61 25.5 2.2 6 E1 1 2 SRM-1646a 62 35.40 0.6 6 A1 1 2 IAEA-433 63 33.8 3.0 4 M1 1 2 MESS-3 64 29.6 1.7 5 M1 1 1 IAEA - SL-1 65 28.8 1.8 6 M1 2 1 IAEA-405 66 32.5 5.0 3 A0 2 2 IAEA-405 68 27.1 1.1 2 M1 2 2 NIST 2710 70 31.3 3.2 6 X1 0 0 DC 73307 71 33.53 3.0 4 A1 1 1 IAEA-433 72 17.66 24.8 6 A1 ? 1 73 28.75 1.6 6 A1 2 2 MESS-3 74 26.955 2.0 6 A1 3 2 BCSS-1 75 32.5 4.0 6 M1 1 1 SRM-1646a 79 27.506 5.3 6 A3 1 1 IAEA-405 80 28.01 2.8 6 A1 3 2 MESS-3 82 30.56 1.7 6 M1 2 1 IAEA-433 83 26 5.2 6 E1 2 1 IAEA-433 84 29.53 2.6 6 A1 3 1 IAEA-433 85 32.7 5.5 3 E0 1 1 IAEA-433 90 5.8 24.1 6 X1 0 0 92 31.6 2.2 6 A3 1 1 IAEA-433

75

Niobium (Nb) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

51a 14 7.1 3 A3 3 1 SDO-1 51c 14.745 0.0 1 X1 0 0 IAEA-433 Potassium (K) (g kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 5.4 5.9 6 E1 1 2 ERA540B 5 18.1 5.5 6 X1 0 0 IAEA-405 7 21.7 5.5 6 A1 3 1 IAEA-433 12 20.600 2.5 6 M1 1 1 IAEA-433 24 19.700 5.6 6 N2 0 0 SRM 2704 28 19.193 0.1 6 X1 0 0 GBW07309 29 17.728 8.2 6 N2 0 0 IAEA-405 35 19.060 11.5 6 N2 0 0 IAEA-405 48 21.600 5.1 6 N0 0 0 SRM2711 51c 20.9853191 0.0 1 X1 0 0 IAEA-433 82 18.612 1.6 6 M1 2 1 IAEA-433 87 11.2 11.6 6 N2 0 0 SRM1633A 91 26 7.7 ? A1 2 1 Rubidium (Rb) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

3b 75.8 3.3 6 N2 0 0 IAEA-433 3c 85 1.2 6 X1 0 0 IAEA-433 5 82 19.5 6 X1 0 0 IAEA-405 12 86.5 1.3 6 M1 1 1 IAEA-433 24 90.6 3.4 6 N2 0 0 SRM 2704 29 81 14.8 6 N2 0 0 35 73.6 9.5 6 N2 0 0 48 90.0 1.9 6 N0 0 0 SRM2711 51c 100.868 0.0 1 X1 0 0 IAEA-433 74 100.83 1.3 6 X1 0 0 BCSS-1 82 78.7 4.6 6 M1 2 1 IAEA-433 86 88 3.4 6 N2 0 0 Soil7 87 70 21.4 6 N2 0 0 SRM1633A

76

Samarium (Sm) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

12 5.00 1.7 6 M1 1 1 IAEA-433 24 5.20 3.3 6 N2 0 0 SRM 2704 29 5.02 4.8 6 N2 0 0 IAEA-405 35 4.6 6.5 6 N2 0 0 IAEA-405 48 5.17 2.1 6 N0 0 0 SRM2711 78 4.58 4.1 6 N0 0 0 IAEA-405 82 4.55 4.6 6 M1 2 1 IAEA-433 86 5.1 2.0 6 N2 0 0 Soil7 87 5 26.0 6 N2 0 0 SRM1633A Scandium (Sc) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

3b 8.75 2.4 6 N2 0 0 IAEA-433 12 8.98 1.6 6 M1 1 1 IAEA-433 24 8.58 2.2 6 N2 0 0 SRM 2704 29 8.3 6.0 6 N2 0 0 IAEA-405 35 8.1 3.7 6 N2 0 0 IAEA-405 48 8.205 0.5 6 N0 0 0 SRM2711 78 7.74 1.6 6 N0 0 0 IAEA-405 82 6.41 2.5 6 M1 2 1 IAEA-433 86 8.3 3.6 6 N2 0 0 Soil7 87 7.84 2.9 6 N2 0 0 SRM1633A Selenium (Se) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 1.01 9.9 6 M1 1 2 ERA540B 5 16 31.3 ? X1 0 0 10 0.434 11.1 6 E1 3 2 12 0.719 4.2 6 M1 1 1 IAEA-433 18 0.22 18.2 4 A8 1 1 20 0.41 22.0 6 A8 1 2 PACS-2 28 1.33 36.1 6 X1 0 0 GBW07309 32 0.54 6.5 3 A8 3 2 MESS-3 35 0.46 10.9 6 N2 0 0 IAEA-405 50 0.9 4.4 6 M1 2 2 AGAL-10 51a 0.87 11.5 3 A8 3 1 IAEA-433 65 0.777 8.1 6 M1 2 1 IAEA-405 68 2.06 3.9 2 M1 2 2 NIST 2710 75 0.89 9.0 6 M1 1 1 SRM-

1646a 83 1.06 10.4 6 M1 2 2 IAEA-433 90 2.9 41.4 6 X1 0 0

77

Silicon (Si) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

5 269 3.7 6 X1 0 0 28 220.929 0.1 6 X1 0 0 GBW07309 51c 198.415486 0.0 1 X1 0 0 IAEA-433 Silver (Ag) (mg kg-1) Lab code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 0.15 6.7 6 M1 1 2 ERA540B 10 0.192 19.8 6 E1 3 2 12 0.152 4.6 6 M1 1 1 IAEA-433 32 0.22 6.4 3 M1 3 2 MESS-3 51a <1 A3 3 1 SDO-1 53 0.23 8.7 4 M1 2 1 MESS-3 65 0.189 10.3 6 A3 2 1 IAEA-405 68 0.99 5.1 2 M1 2 2 NIST 2710 75 0.32 3.1 5 M1 1 1 SRM-1646a 81 0.152 3.3 6 A3 2 2 MESS-2 Sodium (Na) (g kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 11.1 2.7 6 E1 1 2 ERA540B 7 22.9 4.8 6 A1 3 1 IAEA-433 12 24.100 1.7 6 M1 1 1 IAEA-433 24 23.400 2.7 6 N2 0 0 SRM 2704 28 32.762 0.5 6 X1 0 0 GBW07309 29 24.163 3.0 6 N2 0 0 35 23.760 3.7 6 N2 0 0 48 24.250 0.4 6 N0 0 0 SRM2711 51c 25.8061394 0.0 1 X1 0 0 IAEA-433 77 27.039 14.3 5 A1 1 1 IAEA-405 82 22.663 1.9 6 M1 2 1 IAEA-433 86 23.879 2.4 6 N2 0 0 Soil7 87 15.5 2.6 6 N2 0 0 SRM1633A 91 27.6 1.4 ? A1 2 1 Strontium (Sr) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 304 3.0 6 M1 1 2 ERA540B 3c 484 1.4 6 X1 0 0 IAEA-433 5 479 2.5 6 X1 0 0 IAEA-405 10 306.493 1.9 6 E1 3 2 11 434 1.2 3 E1 1 2 IMEP14 12 515 1.1 6 M1 1 1 IAEA-433 14 422 3.3 3 X1 0 0 BCSS-1 19 380 1.0 6 E1 1 2

78

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

24 470 4.9 6 N2 0 0 28 602 0.1 6 X1 0 0 GBW07309 29 339 39.5 6 N2 0 0 33 393 3.0 3 M1 3 2 39 345 0.6 3 E1 2 2 MESS-3 48 476 3.6 6 N0 0 0 SRM2711 50 324.5 1.5 6 E1 2 2 AGAL-10 51c 509.509 0.0 1 X1 0 0 IAEA-433 52 469.3 1.7 6 E1 1 1 IAEA-405 63 414 1.2 4 M1 1 2 MESS-3 65 462 2.5 6 M1 2 1 IAEA-405 68 476 0.8 2 M1 2 2 NIST 2710 70 475 0.4 6 X1 0 0 DC 73307 74 494 0.3 6 X1 0 0 BCSS-1 75 522.7 2.0 6 M1 1 1 SRM-1646a 83 412 4.6 6 E1 2 1 IAEA-433 90 300 7.3 6 X1 0 0 92 484 4.5 6 A3 1 1 IAEA-433 Sulphur (S) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

5 13.9 12.2 6 X1 0 0 51c 7.93 0.0 1 X1 0 0 IAEA-433 Tantalum (Ta) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

24 0.939 8.5 6 N2 0 0 SRM 2704 29 1.01 6.9 6 N2 0 0 35 0.93 10.8 6 N2 0 0 48 0.927 3.7 6 N0 0 0 SRM2711 86 1.04 4.8 6 N2 0 0 87 1 50.0 6 N2 0 0 SRM1633A Terbium (Tb) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

24 0.565 9.7 6 N2 0 0 SRM 2704 35 0.70 5.7 6 N2 0 0 IAEA-405 48 0.607 3.6 6 N0 0 0 SRM2711 82 0.583 3.1 6 M1 2 1 IAEA-433 86 0.7 14.3 6 N2 0 0 Soil7 87 0.87 37.9 6 N2 0 0 SRM1633A Thallium (Tl) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 0.36 5.6 6 M1 1 2 ERA540B

79

Thorium (Th) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

3b 9.28 2.7 6 N2 0 0 IAEA-433 24 9.01 2.9 6 N2 0 0 SRM 2704 29 9.3 7.5 6 N2 0 0 IAEA-405 35 8.3 4.8 6 N2 0 0 IAEA-405 48 9.06 4.5 6 N0 0 0 SRM2711 82 7.02 7.8 6 M1 2 1 IAEA-433 86 8.4 1.2 6 N2 0 0 Soil7 87 6.7 10.4 6 N2 0 0 SRM1633A Tin (Sn) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 3.88 5.4 6 M1 1 2 ERA540B 10 7.946 5.7 6 E1 3 2 11 5.8 8.6 3 E1 1 2 IMEP14 12 7.47 2.9 6 M1 1 1 IAEA-433 19 5.6 3.6 5 E1 1 2 20 4.5 8.9 6 A8 1 2 PACS-2 28 5.12 28.1 6 X1 0 0 GBW07309 33 5.67 4.1 3 M1 3 2 47 6.61 2.7 6 A4 2 1 BCSS-1 65 6.30 5.5 6 M1 2 1 IAEA-405 69 2.27 12.2 3 A8 2 1 75 8.36 4.9 6 M1 1 1 SRM-

1646a Titanium (Ti) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

5 3470 5.5 6 X1 0 0 IAEA-405 12 3610 1.4 6 M1 1 1 MESS-3 28 3159 0.6 6 X1 0 0 GBW07309 51b 3500 5.7 3 E1 4 SDO-1 51c 3434 0.0 1 X1 0 0 IAEA-433 Uranium (U) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

12 2.48 1.8 6 M1 1 1 IAEA-433 29 2.70 10.7 6 N2 0 0 IAEA-405 78 2.58 9.3 6 N0 0 0 IAEA-405 82 2.141 3.1 6 M1 2 1 IAEA-433 86 2.4 8.3 6 N2 0 0 Soil7 87 2.19 12.3 6 N2 0 0 SRM1633A

80

Vanadium (V) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 50.1 4.0 6 M1 1 2 ERA540B 3c 81 14.8 6 X1 0 0 IAEA-433 7 73.9 1.1 6 A4 3 1 IAEA-433 12 72.9 0.9 6 M1 1 1 IAEA-433 13 91.77 1.7 6 A6 1 1 HISS-1 18 91.61 3.8 4 A3 1 1 19 62.2 3.1 6 E1 1 2 24 72.0 5.8 4 N2 0 0 SRM 2704 27 88.8 5.3 3 M1 1 1 GBW 7310 28 72.1 4.3 6 X1 0 0 GBW07309 33 46.1 3.2 3 E1 3 2 NO7004 35 63.9 6.6 6 N2 0 0 IAEA-405 42 54.4 12.2 6 ? 1 2 IAEA-405 43 48.2 4.1 6 M1 1 2 LKSD4 44 73.8 5.1 6 A3 1 1 IAEA-433 46 79.7 4.3 6 A3 1 IAEA-433 50 41.2 1.0 6 ? 2 2 AGAL-10 51c 62.413 0.0 1 X1 0 0 IAEA-433 52 76.6 0.9 6 E1 1 1 IAEA-405 53 71 2.8 4 M1 2 1 MESS-3 63 57.3 4.7 4 M1 1 1 MESS-3 64 73.9 1.5 5 M1 1 1 IAEA - SL-1 65 72.0 0.8 6 E1 2 1 IAEA-405 78 73.7 3.7 6 N0 0 0 IAEA-405 82 71.2 1.5 6 M1 2 1 IAEA-433 85 51.5 1.5 3 E0 1 1 IAEA-433 92 81 3.0 6 A3 1 1 IAEA-433 Ytterbium (Yb) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

24 1.93 8.3 6 N2 0 0 SRM 2704 29 2.28 5.7 6 N2 0 0 IAEA-405 35 1.94 9.3 6 N2 0 0 IAEA-405 48 2.21 4.5 6 N0 0 0 SRM2711 82 1.573 5.4 6 M1 2 1 IAEA-433 86 2.1 4.8 6 N2 0 0 Yttrium (Y) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

51c 25.8 1 X1 0 0 IAEA-433

81

Zinc (Zn) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

2 131 3.8 6 M1 1 2 ERA540B 3c 123 4.9 6 X1 0 0 IAEA-433 5 144 9.7 6 X1 0 0 IAEA-405 7 139 1.2 6 A1 3 1 IAEA-433 8 153.2 5.5 6 A1 1 1 QTM074MS 9 51.85 4.5 5 A1 2 2 IAEA-436 10 202.071 0.6 6 E1 3 2 11 147 1.4 3 E1 1 2 IMEP14 12 142 2.7 6 M1 1 1 IAEA-433 14 112 6.4 3 X1 0 0 BCSS-1 15 126 2.4 6 A1 2 1 IAEA-405 17 135.8 2.5 6 A1 2 2 LGC-6137 19 135 1.9 6 E1 1 2 20 146.8 3.3 6 A1 1 2 MESS-3 21 136.0 0.0 5 A1 3 2 22 144 0.0 6 A1 3 2 MESS-3 23 154.01 3.8 4 A1 3 2 24 292 6.5 6 N2 0 0 SRM 2704 27 140 3.3 3 M1 1 1 GBW 7310 28 143.2 1.1 6 X1 0 0 GBW07309 29 144 22.2 6 N2 0 0 IAEA-405 30 144 3.1 6 A1 1 2 IAEA-433 31a 134 9.7 3 A3 1 2 IAEA-433 31b 126 7.9 3 A3 1 2 IAEA-433 32 142 1.0 3 E1 3 2 MESS-3 33 118 2.2 3 E1 3 2 NO7004 34 99.7634 7.5 6 A1 1 1 IAEA-405 35 150.6 9.0 6 N2 0 0 37 128 9.1 5 A1 2 2 SD-M-2/TM 38 128.85 2.8 2 A1 2 2 IAEA-433 39 122 2.9 3 E1 2 2 MESS-3 40 116 1.3 6 E1 3 2 IAEA-433 42 124.7 13.5 6 ? 1 2 IAEA-405 43 129 7.8 6 M1 1 2 LKSD4 44 140 4.3 6 A1 1 1 IAEA-433 45a 143.76 4.4 4 A1 1 1 IAEA-433 45b 147.5 6.7 6 N2 0 0 IAEA-433 45c 149.5 3.6 6 X1 0 0 IAEA-433 46 160 3.8 6 A3 1 IAEA-433 47 141.2 2.8 6 A1 2 1 BCSS-1 48 157.7 5.4 6 N0 0 0 SRM2711 49 126.7322 2.0 3 A1 2 1 IAEA-433 50 131.2 2.4 6 E1 2 2 AGAL-10 51a 109 4.6 3 A3 3 1 SDO-1 51c 107.985 0.0 1 X1 0 0 IAEA-433 52 150.6 4.3 6 E1 1 1 IAEA-405 53 136 5.9 6 M1 2 1 MESS-3 54 141.4 5.5 5 A1 3 1 GBW-07312 55 156.7 0.4 6 A1 1 2 56 134.906 2.8 5 A1 1 1 IAEA-433

82

Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

57 145.26 2.6 3 A1 2 1 MESS-3 58 168 ? M1 1 2 59 190 5.3 3 A1 3 2 IAEA-433 60 172.84 5.9 3 A1 1 2 IAEA-433 61 122.667 9.5 6 E1 1 2 SRM-1646a 62 157.7 0.6 6 A1 1 2 IAEA-433 63 163 6.7 4 M1 1 1 MESS-3 64 140 2.4 5 M1 1 1 IAEA - SL-1 65 141 5.5 6 M1 2 1 IAEA-405 66 145 4.1 3 A0 2 2 IAEA-405 67 119.62 4.2 6 A1 1 1 IAEA-433 68 151 4.6 2 M1 2 2 NIST 2710 69 117.9 3.9 3 A1 2 1 70 139 1.4 6 X1 0 0 DC 73307 71 162.57 0.9 5 A1 1 1 IAEA-433 72 139.64 13.5 6 A1 ? 1 73a 146.6 5.1 6 A1 2 1 MESS-3 73b 152.3 2.9 6 A1 2 2 MESS-3 74 105.48 0.8 6 A1 3 2 BCSS-1 75 134.6 4.0 5 M1 1 1 SRM-1646a 76 128.681 5.2 7 A1 2 2 77 161 1.2 5 A1 1 1 IAEA-405 78 148.9 4.3 6 N0 0 0 IAEA-405 80 147 2.7 6 A1 3 2 MESS-3 81 156 1.3 6 A1 2 2 MESS-2 82 137.9 4.0 6 M1 2 1 IAEA-433 83 133 3.2 6 E1 2 1 IAEA-433 84 136.05 2.4 6 A1 3 1 IAEA-433 85 93.17 1.8 3 E0 1 1 IAEA-433 86 145 2.1 6 N2 0 0 Soil7 87 69 39.1 6 N2 0 0 SRM1633A 88 146.7 2.2 5 A1 2 1 MESS-3 89 140.5 3.6 6 A1 1 1 IAEA-433 90 79 3.8 6 X1 0 0 92 129 3.9 6 A1 1 1 IAEA-433 Zirconium (Zr) (mg kg-1) Lab Code

Lab. Mean RSD (%)

Number. Replicates


Digestion Code

Acid Code

Quality Control

5 314 11.5 6 X1 0 0 IAEA-405 51c 225.311 0.0 1 X1 0 0 IAEA-433

83

APPENDIX II

GRAPHICAL PRESENTATION OF RESULTS SORTED BY ELEMENT

IAEA-158

84

Aluminium

0

10

20

30

40

50

60

70

80

90

100

23 50 33 69 2 42 19 35 82 78 46 65 27 8 51c

52 63 51b

12 28 53 73 20 44 5 90

Laboratory code number

Al (m

g g-1

)

Laboratory mean ± 1SD (error bar) Dashed Lines = Mean value ± 1SD (Cofino 1st Mode); O = out of scale; X = No QA reported; �= QA bias High; �= QA bias Low; � = no numerical value

85

Antimony

0.00

0.50

1.00

1.50

2.00

2.50

3.00

32 2 50 33 78 86 65 12 82 35 48 24 20 29 3b


Sb (µ

g g-1

)


86

Arsenic

0.0

5.0

10.0

15.0

20.0

25.0

30.0

72 14 29 24 35 32 31 33 87 3b 7 50 2 19 68 12 61 55 11 58 20 65 63 78 45a70 30 92 86 64 73 48 10 51a15 39 46 44 28 83 82 42 36 43 27 75 49 8 17 52


As (µ

g g-1

)


87

Cadmium

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

34 37 38 72 45a51a62 67 28 69 71 42 63 84 81 58 57 76 31 78 47 17 21 15 2 82 60 30 64 65 33 50 22 92 11 46 19 79 73 44 20 27 9 53 3a 12 55 80 8 39 43 83 32 75 89 25 40 74 77 68 54 61 36 49 70 10


Cd (µ

g g-1

)


88

Calcium

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

87 91 51b

2 5 29 86 12 77 28 51c


Ca (m

g g-1

)


89

Chromium

0

20

40

60

80

100

120

140

160

180

200

69 55 23 34 39 50 17 61 58 2 42 79 8 19 38 60 30 18 45b56 49 65 83 20 71 45a62 84 54 7 15 52 68 82 87 73 88 3b 27 89 35 64 53 25 51a57 78 46 44 75 12 86 43 5 92 29 85 10 24 70 76 14 48 59 28 3c 47 63 51c90 36


Cr (µ

g g-1

)


90

Cobalt

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

23 74 50 79 39 40 14 85 34 51a2 20 33 61 92 31 68 72 87 53 63 3b 35 78 45b82 48 44 11 28 75 22 86 65 46 12 43 29 24 64 19 7 45a10 54 83 52 70 37 42 90


Co (µ

g g-1

)


91


Cupper

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

85 67 56 34 36 76 90 18 81 40 14 43 74 31 58 10 91 60 23 9 53 63 44 3c 21 30 42 83 80 39 92 16 75 22 2 64 46 49 82 84 20 72 47 45c15 54 3a 73a17 78 65 33 55 52 25 12 51c38 28 45a19 50 57 59 66 8 73b71 7 68 70 88 11 37 89 32 51a27 62 61 13 5 69


Cu (µ

g g-1

)Copper

92

Iron

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

9 85 34 69 37 23 61 90 55 39 21 42 54 50 2 17 66 33 45a68 43 46 63 19 91 87 45b45c44 62 78 30 59 51b35 7 12 18 80 84 20 52 3c 48 70 86 5 65 11 13 24 92 27 56 8 29 77 3b 53 57 51c73 28 74 82 15 10 71


Fe (m

g g-1

)


93

Lanthanum

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

82 35 86 78 12 48 29 3b 87 24


La (µ

g g-1

)


94

Lead

0.0

20.0

40.0

60.0

80.0

100.0

120.0

34 81 69 14 74 85 62 89 23 9 77 13 37 63 39 40 31 60 78 45a83 19 33 80 17 43 21 18 2 58 27 3c 52 50 30 20 15 64 22 7 61 55 44 32 73a25 36 46 49 84 59 12 42 92 82 3a 53 79 8 65 73b70 28 68 38 67 71 51a47 54 75 10 66 5 88


Pb (µ

g g-1

)


95

Lithium

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

8 45a

2 82 20 63 19 53 83 27 12 52


Li (µg

g-1)


96

Magnesium

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

43 9 52 2 82 50 30 78 65 77 12 63 51c

28 51b


Mg (m

g g-1

)


97

Manganese

0.0

100.0

200.0

300.0

400.0

500.0

600.0

34 40 69 85 37 76 39 2 21 50 17 31 61 22 38 33 66 42 43 91 83 3c 11 19 80 45c10 15 35 28 5 62 84 30 29 92 49 78 74 55 65 14 89 13 46 53 70 44 3a 51b24 63 52 20 68 73 45a18 8 56 77 75 12 57 59 7 51c82 90 27 71


Mn (µ

g g-1

)


98

Mercury

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

61 42 34 7 86 71 40 36 60 2 83 31 6 55 47 50 17 68 1 39 26 15 80 20 92 44 53 14 4 88 3a 41 63 73 76 33 84 32 27 12 8 65 58 11 21 19 18 51a77 28 10 43 45a67


Hg (µ

g g-1

)


99

Methyl Mercury

0.00

0.50

1.00

1.50

2.00

2.50

3.00

83 36 68 1 26 92 65 92b

4 32 20


MeHg

(ng g

-1)


100

Nickel

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

90 34 72 13 40 43 38 23 39 33 61 3a 83 18 17 2 74 11 50 68 79 19 80 42 44 46 73 65 37 84 64 3c 15 20 30 14 82 45 70 31 12 92 53 85 49 66 75 60 8 22 52 71 63 27 10 51 59 62 55 51 56 5 28


Ni (µ

g g-1

)


101

Potassium

0.0

5.0

10.0

15.0

20.0

25.0

30.0

2 87 29 5 82 35 28 24 12 51c

48 7 91


K (m

g g-1

)


102

Rubidium

0.0

20.0

40.0

60.0

80.0

100.0

120.0

87 35 3b 82 29 5 3c 12 86 48 24 74 51c


Rb (µ

g g-1

)


103

Selenium

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

18 20 10 35 32 12 65 51a

75 50 2 83 28 68 90 5


Se (µ

g g-1

)


104

Silver

0.00

0.10

0.20

0.30

0.40

0.50

0.60

51a

2 12 81 65 10 32 53 75 68


Ag (µ

g g-1

)


105

Sodium

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

2 87 82 7 24 35 86 12 29 48 51c

77 91 28


Na (m

g g-1

)


106

Strontium

0

100

200

300

400

500

600

700

90 10 2 50 29 39 19 33 83 63 14 11 65 52 24 70 48 68 5 92 3c 74 51c

12 75 28


Sr (µ

g g-1

)


107

Tin

0

1

2

3

4

5

6

7

8

9

10

69 2 20 28 33 19 11 65 47 12 10 75


Sn (µ

g g-1

)


108

Vanadium

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

50 33 43 2 85 42 63 19 51c

35 53 82 65 24 28 12 78 44 64 7 52 46 92 3c 27 18 13


V (µg

g-1)


109

Zinc

0

50

100

150

200

250

300

350

9 87 90 85 34 74 51c51a14 40 33 69 67 39 3c 61 42 31b15 49 37 76 38 43 92 2 50 83 31a75 56 19 21 53 17 84 82 7 70 72 44 27 64 89 47 65 54 32 12 28 45a22 29 5 30 86 66 57 73a11 88 20 80 45b78 45c68 35 52 63 73b8 23 81 55 48 62 46 77 71 58 60 59 10 24


Zn (µ

g g-1

)


110

Barium

400

500

600

700

800

900

1000

1100

1200

2 28 87 51c

86 82 29 3c 12


Ba (µ

g g-1

)

Bromine

100

140

180

220

260

300

86 5 35 48 3b 29 87


Br (µ

g g-1

)

Caesium

2.00

2.50

3.00

3.50

4.00

4.50

5.00

5.5082 86 35 48 29 3b 12 87


Cs (µ

g g-1

)

Cerium

40

45

50

55

60

65

70

82 12 78 87 3b 29 35 86 48


Ce (µ

g g-1

)


111

Europium

0.60

0.70

0.80

0.90

1.00

1.10

1.20

1.30

35 48 29 86 24 12 82


Eu (µ

g g-1

)

Hafnium

2.00

3.00

4.00

5.00

6.00

7.00

8.00

12 87 35 86 48 29 24


Hf (µ

g g-1

)

Lutetium

0.10

0.15

0.20

0.25

0.30

0.35

0.4035 87 29 86 24


Lu (µ

g g-1

)

Molybdenum

0.00

2.00

4.00

6.00

8.00

10.00

2 51a

51c

12 87 29


Mo (µ

g g-1

)


112

Neodymium

0.0

10.0

20.0

30.0

40.0

50.0

87 82 12 29 35 86


Nd (µ

g g-1

)

Samarium

2.00

4.00

6.00

8.00

82 78 35 12 29 87 86 48 24


Sm (µ

g g-1

)

Scandium

5.00

6.00

7.00

8.00

9.00

10.0082 78 87 35 48 29 86 24 3b 12


Sc (µ

g g-1

)

Tantalum

0.00

0.50

1.00

1.50

2.00

48 35 24 29 86 87


Ta (µ

g g-1

)


113

Terbium

0.00

0.50

1.00

1.50

24 82 48 86 35 87


Tb (µ

g g-1

)

Thorium

0.00

2.00

4.00

6.00

8.00

10.00

12.00

87 82 35 86 24 48 3b 29


Th (µ

g g-1

)

Titanium

28002900300031003200330034003500360037003800

28 51c

5 51b

12


Ti (µg

g-1 )

Uranium

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

82 87 86 12 78 29


U (µg

g-1 )


114

Ytterbium

0.00

0.50

1.00

1.50

2.00

2.50

3.00

82 24 35 86 48 29


Yb (µ

g g-1

)


115

APPENDIX III

LIST OF PARTICIPANTS

IAEA-158

116

LIST OF PARTICIPANTS

Dr. A. Cullaj & Ms. Sonila Duka Faculty of Natural Sciences University of Tirana TIRANA ALBANIA

Dr. M. Wu National Measurment institute 1 Suakin Street Pymble N.S.W. 2073 AUSTRALIA

Mr. D. Choueifati Sydney Water Corporation 51 Hermitage Rd West Ryde Sydney, NSW, 2114 AUSTRALIA

Dr. A. TÖRVÈNYI International Atomic Energy Agency Agency's Laboratories A-2444 Seibersdorf AUSTRIA

Dr. Stephen Astegger Dept: FPA Lenzig AG werkstrasse 1 A-4860 Lenzing AUSTRIA

Melina Dzajic-Valjevac Hydro-engeneering institut Stjepana Tomica 1 71000 Sarajevo BOSNIA and HERZEGOVINA

Dr. Deborah Favaro IPEN-CNEN/SP Av Professor Lineu Prestes,2242 Cidade Universitaria CEP 05508-000 Sao Paulo BRAZIL

Dr. M. Luiza Godoy Inst. de Radioprotecao e Dosimetria Av. Salvador Allende s/no CEP 22780-160 recreio Rio de Janeiro RJ BRAZIL

Prof. Dr. E. A. De Nadai Fernandes Laboratorio de Radioisotopos Centro de Energia Nuclear na Agricultura (CENA/USP) Univ. de Sao Paulo, 13416-000 Ave.Centenario 303, Piracicaba - SP BRAZIL

Dr. L.F. Niencheski and M. Milani Fundacao Universidade do Rio Grande Laboratorio de Hidroquimica C.P. 474 96201-900 Rio Grande, RS BRAZIL

117

Ms Lybka Chepanova Executive Agency for the Environment (MOEW) Regional Laboratory-Burgas,k-s Lazur 67 Perushtica Str, P.O. Box 675 8000 Burgas BULGARIA

Dr. Holger Hintelman NSERC Industry Research Chair, Department of Chemistry 1600 West Bank Drive Peterbourg Ontario K9j 7B8 CANADA

I.Rheault, M.Lucotte, P.Pichet & H.V. Tra Dept. of Chemistry U.Q.A.M. C.P. 8888, Succ Centre Ville Montreal, P.Q. H3C 3P8 CANADA

Dr. R. Flett & Xiang Wei M.Sc. Flett Research Ltd. 440 Desalaberry Ave Winnipeg MANITOBA R2L 0Y7 CANADA

Jennifer Cram ALS, Environmental 1988 Triumph St. VANCOUVER B.C. V5L IK5 CANADA

Dr Manuel A. Leiva-Guzmàn Centro National del Medio Ambiente CENMA Larrain 9975 La Reina Santiago CHILE

Dr. E. Valdes Universidad Tecnica Federico Santa Maria Dept. of Chemistry, Av. Espana 1680 P.O. Box 110-V VALPARAISO CHILE

Drs. Oscar Andonie Comisiòn Chilena de Energía Nuclear LAb Análisis por Activación Neutrónica CEN, la Reina, Nueva Bilbao 12501 Santiago de Chile CHILE

Sergio Marín Comisiòn Chilena de Energía Nuclear Lab Análisis Químoco CEN, lo Aguirre, Amunátegui 95 Santiago de Chile CHILE

B.Sc. S. Mladinov & B.Sc. S.Dikovic Institut of Public Health-Istria County Dept for Protection and Improvment of Environment p.p 192 (Nazorova 23) 52100 PULA CROATIA

Dr. M.S. Gjeldum PLIVA Quality asssurance Prilaz baruna Filipovica 25 10000 Zagreb CROATIA

Mr. J. Pongracic Croatian National Inst. of Public Health, Rockefellerova 7 10000 ZAGREB CROATIA

118

Ms. Marijana Matek Saric Institute of public Health Kolovar 2 2300 Zadar CROATIA

Sr. Misael Diaz-Asencio, Head of environmental Laboratory Center of environemental Studies Carretera Castillo de Jagua KM 1 1/2 A.P. 5 , C. P. 59350 Ciudad Nuclear . Cienfuegos CUBA

RNDr K. Jakubec, Ing J. Koubec Ecochem, a.s. Na Harfe 9/336 Prague 9 CZ-190 00 CZECH REPUBLIC

Dr. M. M. Larsen National Environmental Research Inst. Frederiksborgvej 399 P.O. Box 358 DK-4000 Roskilde DENMARK

Mereoni Degei Gonelevu Institute of applied Sciences Univ.of South Pacific SUVA FIJI

T. Guyot Centre de Recherche sur les Ecosystèmes Anthropisés (CRELA) UFR de Sciences, Université de la Rochelle Av. Marillac F-17042 LA ROCHELLE Cedex FRANCE

Dr. Baghdad Ouddane Lab. Chimie Analytique Bat C8 Univ. de Lille F-59655 VILLENEUVE D'ASCQ FRANCE

Emmanuel Wafo & Thérèse Schembri Université de la Méditerranée Laboratoire d'Hydrologie et de Molysmologie Aquatique 27 Blvd. Jean Moulin F-13385 Marseille Cedex 5 FRANCE

Michel Robert et Carine Churlaud Centre Commun d'Analyses Université de la rochelle 5 allées de l' océan 17071 La Rochelle Cedex 9 FRANCE

Mr Auger IFREMER Centre de Nantes Rue de l'lle d' Yeu B.P. 21105 F-44311 NANTES Cedex 03 FRANCE

Dr Marina Coquery CEMAGREF, Groupement de Lyon Freshwater Systems Dpt. 3bis, quai Chauveau, CP 220, 69336 Lyon cedex 09 FRANCE

Dr. Ute Kohlmeyer GALAB Laboratories GmbH Max-Planck Str.1 D-21502 GEESTHACHT GERMANY

119

Peter Morgenstern Univ. Leipzig Fak. F. Physik, ABT.NFP Linnestr. 5 D-04103 Leipzig GERMANY

A.Y Karikari, M. Dorleku Water Research Institute (CSIR) Box M32 Accra GHANA

E. Dassenakis & M. Scoullos University of Athens, Dept. of Chemistry, Section III Laboratory of Environmental Chemistry Panepistimiopolis 15771 ATHENS GREECE

Dr. J Arunachalam Head, National Center for Compositional Characterisation of Material (CCCM) Ecil post, Hyderabad 500 062 Andhrapradesh INDIA

Mr V.D. Puranik Environmental Assesment Division Bhabha Atomic Research Centre Trombay 400 085 MUMBAI INDIA

Dr. M. Reza Einghalaie Laboratories Affairs Bureau, Dept. of the Environment (DOE) Hemmat expway Paradisan Eco Park Environmental Research Center INDIA

Dr B. Mehrabi Iranian Mineral Processing Research center IMPRC Tehran IRAN

Drs. Edna Shafer Israel Oceanographic & Limnological Research, Ltd. Tel Shikmona, P.O. Box 8030 31080 HAIFA ISRAEL

Dr Maria Belli Head of Analytical Laboratories Italian Environmental Protection Agency (APAT) Via di Castel Romano, 100 00128 Roma ITALY

Dr. M. Gerotto ARPAV-DAP Di Venezia Servizio Laboratori Via Lissa,6 30174 MESTRE (VE), ITALY

Prof. M. Schintu Universita di Cagliari Dipartimento di Sanità Publica via Porcell 4 I-09100 CAGLIARI ITALY

Drs. L. Bodano, M. Dentoni A.S.L N°8 PMP Area Chimico Farmacologica Ambiantale Viale Ciusa 6/8 I-09131 CAGLIARI Sardegna ITALY

120

Galina Garnaga Center of Marine Reseach Taikos pr.26 LT-91149 Klaipeda LITHUANIA

Dr. W Sun Laboratory of Public Health, Dept of Health Estrada dos Parses, Edif Laboratorio de Saude Publica Macao MACAO

Mr. Devindranath DINDYAL Divisional Scientific Officer National Environmental Laboratory Ground Floor National Laboratory Complex Reduit MAURITIUS

Dr. L. Rosales Hoz & S. Santiago Pèrez Universitad Nacional Autonoma de Mexico Inst. de Ciencias del Mar y Limnologia Apartado postal 70-305, Circuito Exterior Ciudad Universitaria, Mexico 04510 MEXICO

Dr. Juan Manuel Alfaro Barbosa Facultad de Ciencas Quimicas, UANL, Division Posgrado Guerrero S/N esquina con Progreso, Col. Treviño CP 64570 Monterrey Nuevo León MEXICO

Ms. S. Azemard International Atomic Energy Agency AAS lab 4 quai Antoine 1er 98012 Monaco Cedex MONACO

Mr. B. Hacht Univ. Mohamed 1er Faculté des Sciences d'Oujda Department de Chimie 6000 OUJDA MOROCCO

Samir Benbrahim, Rachid Chifri & Bouthir Zohra I.N.R.H Inst National des recherches Halieutiques 2, rue Tiznit CASABLANCA 01 MOROCCO

Dr. H. Hovind Norwegian Institute of Water Research P.O. Box 173 KJELSAS N-0411 OSLO NORWAY

Ahmed Almawali Food and Environment Monitoring center (MRME & WR) P.O. box 323 Muscat - Postal Code 113 OMAN

Dr Shahida Waheed Pakistan Inst. of Nuclear Science & Technology MNSR Lab, NCD PINSTECH Post Office Nilore ISLAMABAD PAKISTAN

Dr. Soledad Osorio DIGESA Las amapolas 350 Urb San Eugenio - Lince Lima PERU

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P. Bedregal, B. Torres, P.Mendoza & M. Ubillús Instituto Peruano de Energia Nuclear Dpt de Química-Nuclear related Analytical Techniques Av Canada 1470 Lima 41 PERU

Prof. Henryk Matusiewicz Politechnika Poznanska Dept of Analytical Chemistry Piotrowo 3 60-965 Poznan POLAND

Wojciech Kwiatek Institut of Nuclear Physics Departement of Applied Spectroscopy ul. Radzikowskiego 152 31-342 Krawow POLAND

Dr. E. Pereira Dept. of Chemistry University of Aveiro, Campus de Santiago P-3810-193 Aveiro PORTUGAL

Ing. I. Moura Instituto do amblente rua da Murgueira Zambujal 9/9A Apart 7585 Alfragide 2721-865 Amadora PORTUGAL

Ibrahim S. Al-Darwish Director Central Environment Laboratory Supreme council For Environment P.O.Box 7634 Doha QATAR

Dr. S. Radan & D. Secrieru National Institute for Marine Geology 304 Mamaia Blvd Constanta RO 87000 ROMANIA

A.L. Kerzin Institute of Geology of ore deposits Petrography mineralogy and geochemistry (IGEM) ras Staromonetny per35 119017 Moskow RUSSIA

Dr. D. B. GLADILOVICH Lumex LTD Moskovsky pr19 190005 St Petersburg RUSSIA

Dr. Lyapunov Russian Academy of Sciences Geological Institute Pyzhevsky Line 7 119017 Moscow RUSSIA

Dr. V.I. Koudriashov Inst. of Physic of St. Petersburg State University Dept.. of Physics & Atmosphere 1 Ulianovskaia St., Petrodvorets 198504 St. PETERSBURG RUSSIA

Prof A.V. Syroeshkin State Oceanographic Inst. Kropotkinsky Lane 6 119034 MOSCOW RUSSIA

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Drs. V. Martynov, L. Kabina & G.shulyak Petersburg Nuclear Physics Inst. Gatchina 188300 LENINGRAD District RUSSIA

Ms. Irina KORPAKOVA Research Institute of the Azov Sea Fishery Problems (AzNIIRKH) Beregovaya street 21/2 344006 ROSTOV-ON-DON RUSSIA

Mrs. V. Radegonde, C. Barra & D. Tirant Seychelles Bureau of Standards P.O. Box 953 Victoria, Mahé SEYCHELLES

Vesna Rozic ERICO, Institute for Ecological Research Koroska 58 pp 22 3320 Velenje SLOVENIA

Philile Mthethwa & Roland A david Laboratory Manager Council for Scientific & Industrial Research(CSIR) P. O. Box 17001, Congella 4013 Durban SOUTH AFRICA

Drs Benedicto, Guerrero & Jornet I.E.O, Centro Oceanografico de Murcia C/Varadero N° 1 30740 San Pedro del Pinatar Murcia SPAIN

Drs. Mahmoud Saleh Soliman & Rawnak Jabbour Syrian Arab Republic Ministry of Local Administration and Environment Environemental studies center"ESC" 17 Nesan Str, PO Box 36782 Syria Damascus-Kafer SYRIAN ARAB REPUBLIC

Prof. Meng-Hsien Chen Dept. of Marine Biotechnology and Resources National Sun Yat-sen University Kaohsiung 80424 TAIWAN

Dr. P. Sungpuag , Dr. R. Kongkachuichai & Mrs. N. Dhananiveskul Mahidol University Institute of Nutrition Phuthamonthon4 73170 NAKHON PATHAM THAILAND

Mr. L. Chouba, H.Amara & Ms. Tissaoui Cherifa Institut National des Sciences et Technologies de la Mer INSTM, Lab. des Métaux Traces Port de pêche 2060 La Goulette, Tunis TUNISIA

Professeur Abderrazak Hedhili Toxicological Laboratory Centre d'Assistance Medicale Urgente 10 rue Aboul Kacem Chebbi 1008 Montfleuri Tunis TUNISIA

Dr. F. Kucuksezgin Inst. of Marine Sciences & Technology Dokuz Eylul University Inciralti 35340 IZMIR TURKEY

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Dr. S. Yemenicioglu & Prof. Suleyman Tugrul M.E.T.U. - Inst. of Marine Sciences P.O. Box 28 33731 Erdemli-MERSIN TURKEY

Drs. Oya Algan & Erdogan Okus Istanbul University Inst. of Marine Sciences & Management Muskule Sokak No.1 34470 Vefa ISTANBUL TURKEY

Mr. Bilal Dikmen Cevre Bakanligi Eskisehir yolu 8km Ankara TURKEY

Dr. A. Fisher Dept. of Environmental Sciences University of Plymouth Drake Circus Plymouth, Devon PL4 8AA U.K.

Mrs Thi Bolam CEFAS Barnham Laboratory Remembrance Avenue Burham-on-Crouch CMO 8HA, ESSEX U.K.

Dr. B. Lasorsa Battelle Marine Sciences Laboratory 1529 W. Sequim Bay Rd. Sequim, Washington 98382 U.S.A

Frank Mc Farland Brooks Rand,LLC 3958 6th Ave. N.W. Seattle WASHINGTON 98107 U.S.A

Dr. Meifang Zhou Water Quality Analysis Division South Florida Water Managment District 1480 Skees Rd, West Palm Beach FL 33411 U.S.A

Mrs. Y. Denga, L. Hapchenko Ukranian Scientific Center of the Ecology of the Sea 89 Frantsuzki Blvd ODESSA 65009 UKRAINE

Ms Amina Ahmed Environmental Laboratory Dubai Central Laboratory Dept. Dubai Minucipality PO.Box. 7463 Dubai UNITED ARAB EMIRATES

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APPENDIX IV

REFERENCE SHEET FOR IAEA-158 Marine Sediment

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International Atomic Energy Agency Analytical Quality Control Services

Wagramer Strasse 5, P.O. Box 100, A-1400 Vienna, Austria

REFERENCE SHEET

REFERENCE MATERIAL

IAEA-158

TRACE ELEMENTS AND METHYLMERCURY IN MARINE SEDIMENT

Date of issue: 31 March 2008

Recommended values: Trace Elements (Based on dry weight)

Element Concentration 1 (mg kg-1)

Std Deviation 2 (mg kg-1)

n 3

Silver 0.180 0.033 5 Arsenic 11.5 1.2 21 Cadmium 0.372 0.039 25 Cerium 61.1 5.4 5 Cobalt 9.2 1.1 17 Chromium 74.4 5.8 23 Caesium 3.73 0.34 6 Copper 48.3 4.2 44 Europium 1.079 0.061 5 Lanthanum 30.2 2.2 7 Manganese 356 24 23 Nickel 30.3 2.9 22 Lead 39.6 4.7 29 Rubidium 82 10 7 Antimony 1.34 0.18 8 Samarium 4.94 0.32 6 Tin 5.84 0.82 5 Strontium 473 25 8 Uranium 2.42 0.28 5 Vanadium 73.0 3.7 9 Zinc 140.6 9.5 41

1 Mean values expressed on a dry-weight basis. 2 Standard deviation of the mean. 3 Number of Laboratory means from the total which were used by Cofino model to calculate the Recommended values.

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Recommended values: Matrix and Minor Constituents (Based on dry weight)

Element Concentration 1 (g kg-1)

Std Deviation 2 (g kg-1)

n 3

Aluminium 51.8 3.4 7 Calcium 64.9 5.8 5 Iron 26.3 1.4 24 Potassium 20.0 1.6 7 Sodium 23.8 1.0 7

Information values

(Based on dry weight) Element Concentration 1

(mg kg-1) Std Deviation 2

(mg kg-1) n 3

Barium 1028 46 4 Bromine 224 15 4 Hafnium 6.23 0.4 5 Mercury 0.132 0.014 24 Lithium 32.5 3.7 4 Lutetium 0.306 0.03 5 MeHg4 0.00141 0.0004 10 Magnesium 10390 960 4 Molybdenum 4.87 0.8 5 Scandium 8.32 0.39 5 Tantalum 0.97 0.12 5 Terbium 0.63 0.097 4 Thorium 8.89 0.58 5 Titanium 3490 170 4 Ytterbium 2.08 0.18 4

1 Mean values expressed on a dry-weight basis. 2 1 standard deviation of the mean. 3 Number of Laboratory means from the total which were used by Cofino model to calculate Recommended and Information values. 4 Concentration reported as mg Hg kg-1

Determination of reference values The values listed above were established on the basis of results submitted by laboratories that had participated in an international intercomparison exercise, organized in 2006. The details concerning the criteria for qualification as recommended or information value can be found in the “Report on the world-wide intercomparison exercise for the determination of trace elements and methylmercury in marine sediment IAEA-158” [1]. This report is available free of charge upon request.

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Intended use This material is intended to be used as a reference material for the measurement of trace elements and methylmercury (MeHg) in sediment samples. It can also be used as a quality control material for the assessment of analytical procedures, in the elaboration and validation of analytical methods, and for educational purposes. Origin and preparation of the material

In November 2004, a large quantity of marine sediments was collected from Kilbrannan Sound, south east of the island of Arran, in the Clyde River estuary, Scotland, UK. The material was collected and supplied to the IAEA through collaboration with the QUASIMEME Laboratory Performance Studies Programme. The material was freeze dried by QUASIMEME and sent to IAEA MEL for further processing and bottling. The dried, material was hand sieved (315 µm) by MESL staff. Approximately 70% of particles had sizes below 100 µm. Aliquots of about 25 g were packed into glass bottles with polyethylene caps and sealed in plastic bags. Approximately five hundred units of the material were prepared. The homogeneity of this material for trace elements was tested using a standard protocol and found to be satisfactory. Homogeneity Extensive homogeneity tests were carried out on this material in order to ensure its suitability as an intercomparison sample. The between-bottle homogeneity was tested by the determination of the concentration of some typical elements (Cd, Cu, Fe, Pb, Mn, Hg and Zn) on sample intakes of 0.25 g taken from 6 bottles. The within-bottle homogeneity was assessed by 6 replicate determinations on the re-homogenized content of one bottle. The uncertainty of the analytical methods was assessed for each element by 5 replicate measurements on one digest solution or by 5 replicate measurements of a certified reference for Hg.

An F-test at a significance level of 0.05 was performed for the different metals and did not reveal significant differences between within- and between-bottle variances, indicating that the heterogeneity observed was relatively consistent, and independent of how the material was distributed. Results of Hg showed unhomogeneity of the material linked to “outliers” results; as a consequence Hg was classified as an information value. As no extensive study of homogeneity was perform for MeHg, by precaution the reference value is also classified as information value.

It was concluded that the material was homogeneous for the elements tested (at the exception of Hg) at an analytical portion of 250 mg and above; it is therefore suitable for use as an intercomparison sample [1].

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Instructions for use The recommended minimum sample size for analysis is 250 mg. Analysts are reminded to take appropriate precautions in order to avoid contaminating the remaining material in the bottle. The bottle should be thoroughly mixed by shaking before use and tightly resealed immediately after use. The material should be stored in the dark and kept below 25 ºC. Since the moisture content can vary with the ambient humidity and temperature, the water content of this material must be determined in a separate sub-sample (not used for analysis) by drying to a constant weight (~24 hours) at 105°C just prior to analysis. Final results should always be reported on a dry weight basis. Failure to compensate for moisture content will lead to underestimation of the results. It appears evident during data treatment that some elements (Al, Cr, Fe, Mn, Sr and V) could be partially solubilized. The addition of hydrofluoric acid is necessary to achieve accurate data for Al and V. For elements like Cr, Fe, Mn and Sr, strong acid digestion procedure is recommended. Legal disclaimer The IAEA makes no warranties, expressed or implied, with respect to the data contained in this reference sheet and shall not be liable for any damage that may result from the use of such data. Reference [1] M. J. Campbell, S. Azemard and J. Oh, 2008. Report on the World-wide

intercomparison exercise on the determination of trace elements in IAEA-158 marine sediment. IAEA/AL/187, IAEA/MEL/82, IAEA, Austria.

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