practical examples on traceablity, measurement uncertainty and validation in chemistry; vol 1 by...

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ISBN 978-92-79-12021-3

Practical Examples on

Traceability,Measurement Uncertainty and Validation in ChemistryVolume 1

Edited by

Nineta Majcen, Philip Taylor

Authors:Ljudmila Benedik

Steluta Duta

Koit Herodes

Monika Inkret

Veselin Kmetov

Allan Künnapas

Ivo Leito

Bertil Magnusson

Urška Repinc

Philip Taylor

Emilia Vassileva

The mission of the JRC is to provide customer-driven scientific and technical support for the conception, development, implementation and monitoring of EU policies. As a service of the European Commission, the JRC functions as a reference centre of science and technology for the Union. Close to the policy-making process, it serves the common interest of the Member States, while being independent of special interests, whether private or national.

Producing reliable measurements in analytical chemistry can be rather demanding.Some would say an uphill struggle. Comparable to mountain walking. Hard work, but then the satisfaction of reaching the top is absolutely great. And so is the view.

As with all human endeavour, it always helps to know what you are doing, thus theoretical knowledge forms the basis. Likewise in analytical chemistry. Understanding the measurement science, the metrology, is important. That is why in the international standard ISO/IEC-17025 “General requirements for the competence of testing and calibration laboratories” section five deals with technical requirements such as traceability, validation and uncertainty. The European Life Long Learning Programme TrainMiC®, created in 2001, produced material for teaching the theory.As excellence in theory does not necessarily mean mastering practice, a need for developing practical examples later arose. This is what you can find in this book, which is intended as a first of a series of such compilations.

Inspired by the NORDTEST “Trollbook”, we also decided to have a mascot. For each volume, a different one, which would be taken from the treasure of European fairy tales and legends.

For this first volume, the fairy tale character of Kekec (pronounced as Kekets) was chosen. Kekec is a brave, clever and cheerful shepherd boy who lives in Slovenian mountains. He always brings good to the people that surround him and he helps those that are in trouble. And in that sense, that is what is the intention of this book.

We hope it succeeds in doing so.

Nineta MajcenPhilip Taylor

EUR22791/2 EN - 2010

Practical Examples on

Traceability,

Measurement Uncertainty

and Validation

in Chemistry

Volume 1

Second edition

Edited by

Nineta Majcen, Philip Taylor

Authors:Ljudmila Benedik

Steluta Duta

Koit Herodes

Monika Inkret

Veselin Kmetov

Allan Künnapas

Ivo Leito

Bertil Magnusson

Urška Repinc

Philip Taylor

Emilia Vassileva

The mission of the JRC-IRMM is to promote a common and reliable European measurement system in support of EU policies.

European CommissionJoint Research CentreInstitute for Reference Materials and Measurements

Contact informationAddress: Retieseweg 111, B-2440 Geel, BelgiumE-mail: [email protected].: +32 (0)14 571 605Fax: +32 (0)14 571 863

http://irmm.jrc.ec.europa.eu/http://www.jrc.ec.europa.eu/

Legal NoticeNeither the European Commission nor any person acting on behalf of the Commission is responsible for the use which might be made of this publication.

Freephone number (*):00 800 6 7 8 9 10 11

(*) Certain mobile telephone operators do not allow access to 00 800 numbers or these calls may be billed.

More information on the European Union is available on the Internet (http://europa.eu).

Cataloguing data can be found at the end of this publication.

JRC 59026

EUR 22791/2 ENISBN 978-92-79-12021-3ISSN 1018-5593doi: 10.2787/10402

© European Union, 2010

Reproduction is authorised provided the source is acknowledged

Printed in

3

INTRODUCTION ..................................................................................................................5

HOW TO USE THE BOOK ...................................................................................................6

ABOUT THE AUTHORS .....................................................................................................11

CHAPTER 1 ..........................................................................................................................17

Analysis of Gold Alloys by Flame Atomic Absorption Spectrometry

Veselin Kmetov, Emilia Vassileva

CHAPTER 2 ..........................................................................................................................51

Determination of Calcium in Serum by Spectrophotometry

Steluta Duta, Philip Taylor

CHAPTER 3 ..........................................................................................................................81

Determination of Radium in Water by α-Spectrometry

Ljudmila Benedik, Urška Repinc, Monika Inkret

CHAPTER 4 ....................................................................................................................... 121

Determination of Polar Pesticides by Liquid Chromatography Mass Spectrometry

Allan Künnapas, Koit Herodes, Ivo Leito

CHAPTER 5 ....................................................................................................................... 157

Determination of Ammonium in Water by Continuous Flow Analysis (CFA) and Spectrometric Detection

Bertil Magnusson

APPENDIX 1 ..................................................................................................................... 193

TrainMiC® Exercises (‘white pages’)

APPENDIX 2 ..................................................................................................................... 209

Briefing of the trainees on the example session

TABLE OF CONTENTS

4

Practical examples on traceability, measurement uncertainty and validation in chemistry

Abbreviations

CRM C

RM R

QC Q

PT P

ILC I

5

If you will tell it to me, I will forgetIf you will show it to me, I will forget

If you involve me, I will remember.

Xun ZiChinese philosopher

310-237 BC

C

ITI I C I

T

T I I CR

P

IT

T T M C® TI R M M

C R CR

T M C®T M C®

T M C® LL L T M C®

Introduction

6

T M C®T M C®

T T M C®T M C®

T M C®

How does a standardised TrainMiC® example look like?

T M C®

exercises TM

T

T

‘yellow pages’ T M C®

T ‘white pages’

How to use the Book

7

How to use the Book

Traceability

Validation

Measurementuncertainty Traceability

Validation

Measurementuncertainty

Figure 1. Harmonised TrainMiC® example

T ‘green pages’I

‘blue page’I

What is a recommended approach of conducting a TrainMiC®

example session?

T T M C® T M C®T M C®

8


I T M C® T M C®

MM

M

T

nominate a rapporteur

IT

T M C®

About the structure of this handbook

I T M C®

P P

T

Nineta Majcen and Philip Taylor

AcknowledgmentT M I R

9

How to use the Book

Figu

re 2

. A p

roce

ss o

f con

duct

ing

a co

mpl

eteT

rain

MiC

® e

xam

ple

11

Introduction

Philip Taylor

P P T PR

C I RM M R C

TC C

C CCQMT M C®

T

T M C® T M C®M

Nineta Majcen

M LP

I

MT M C® T M C®MT M C®

M R

Chapter 1

Veselin Kmetov

PC C

C P

About the Authors

12


ICP ICP MT

IC Q

T M C®T M C®

Emilia Vassileva

I L MP

ICP M

II R M M

I MQ QC

T M C® T M C® MT M C®

Chapter 2

Steluta Duta

I M R LM R I M RMLR M P C MP I RI M RML

I IRT ICP M

CRMT M C® M T M C®

R

About the Authors

13

Philip Taylor

Chapter 3

Ljudmila Benedik

LC I

L P CC T L

I R M MR C C

IM P I MP

IT M C®

Urška Repinc

RI L

R

I P

M C

I I TR C C

14


Monika Inkret

M I M I RL P M

I R MM R C C T

ML

L

M C C C R

C

T M C®

Chapter 4

Allan Künnapas

M T I MQ C R LC M

C L T P PL C M

TLC M

Q C R

LC LC M I M

Koit Herodes

P T

T

About the Authors

15

T TLC M

M

LC MT T C

Ivo Leito

P I L P T

T

IR C M LC M M

RI I

P MP M

M C M

M C

Chapter 5

Bertil Magnusson

MP C

LR R ICP

I P T R IM C

I Q QCI M

L I

16


Q C LI ICP M RT M C®

T M C®

Chapter 1


Veselin Kmetov, Emilia Vassileva

TrainMiC example summary form (‘blue page’) A short introduction to the analytical procedure (‘slides’) All input needed to do the three exercises (‘yellow pages’) The solved exercises (‘green pages’)

17

18


TrainMiC example summary form

I. General information about the example

Measurand Mass fraction of Au in gold alloys (‰)

Example number Ex-06

Authors of the example Veselin Kmetov, Emilia Vassileva

Analytical procedureDetermination of gold in jewellery gold alloys by flame atomic

absorption spectrometry

Customer’s requirement U = 9 ‰ (k = 3)

19


II. Attached files

File number, type

and nameContent of the file

File is

attached Remark

Yes No

1 -

I

Ex-06-1-I-Au-

alloys-FAAS-2006-

Ver1.ppt

About the analytical procedure: short introductionGiven by the

lecturer

2 -

Yel

low Ex-06-2-Y-Au-

alloys-FAAS-2006-

Ver1.doc

PART I Description of the analytical procedure

Each

participant

receives own

copy and

may keep it

PART II

The customer’s requirements

concerning the quality of the

measurement result

PART III

Validation of the measurement

procedure – relevant equations and

measurement data

PART IV

Measurement uncertainty of the result

– relevant equations and measurement

data

3 -

Gre

en

EX-06-3-G-Au-

alloys-FAAS-2006-

Ver1.doc

PART IEstablishing traceability in analytical

chemistry

PART IISingle laboratory validation of

measurement procedures

PART III

Building an uncertainty budget

Addendum 1: By spreadsheet approach

Addendum 2: By dedicated software

III. History of the example

Version Uploaded on the webhotel Short description of the change

0 April 2007 -

1

2

20

Practical examples on traceability, measurement uncertainty and validation in chemistryPractical examples on traceability, measurement uncertainty and validation in chemistry

A short introduction to the analytical procedure


21


×

22



23


24


Analytical procedure

Determination of gold in jewellery gold alloys by Flame Atomic

Absorption Spectrometry

PART I ...................................................................................................................................25

Description of the analytical procedure

PART II .................................................................................................................................33

The customer’s requirements concerning the quality of the measurement result

PART III ................................................................................................................................34

Validation of the measurement procedure – relevant equations and measurement data

PART IV ................................................................................................................................35

Measurement uncertainty of the result – relevant equations and measurement data

All input needed to do the three exercises ‘yellow pages’

25


Task description

TT M

TISO 9202:1991 m m

I

I

T

T than k

Tk

TI . R

1. ISO/TC 174. rev.N71. Gouda 1992 Determination of gold in gold jewelry allows – ICP solution spectrometric method using yttrium as internal standard

2. CNR-PRO Art Project (1998) Tecniche spettrometriche alternative alla copellazione per il saggio delle leghe dioro

Scope

T aqua regiaT

TI

T

PART I. Description of the analytical procedure

26


−

Figure 3. Flow chart of the analytical procedure for determination of gold in gold alloys

27


Reagents

M − aqua regia CP M P P

Apparatus

Id

P − L d −L

L d LC

L d LC

P I


Sample preparation procedure

− T

L L aqua regia

TC C C

L C

TC

P

Calibration

L aqua regia C T

28


T

TT

Atomic absorption measurement

I I

I L I−

R

I T

T

29


Table 1. Instrumental parameters for ASDI-FAAS determination of Au

FAAS parameters Values ASDI parameters

Au spectral line [nm]

Au spectral slit [nm]

242.8

0.7

Ql-

aspiration rate 6.4 mL min-1 checked by BDW

Injection time 5 s; Injection volume ≈ 0.530 μL

Au hollow cathode lamp current [mA] 10 Washing time 10 s; Total replicate time 15 s

Air/C2H

2 units

Observation high [mm]

50/18

6

Smoothing Savitzky-Golay 24 points

Ensemble summation N signal profiles

Working range μg g-1

Deuterium BG corrector

37−43

OFF

Pseudo plateau 3 s

Sampling mode (St1 _ sample _ St

2 ) × N

Readings – points [s] 50 Total time for one set 66 s

30


Calculations

Concentration of initial standard solution made up from pure gold

Cm Au

GAupureAu purity

_ ._ _

_9100

99 9410=

××

C Au_ 999.9 μ

m pureAu_

G CAu purity−

C

Concentration of calibration standard solutions

C CG

GSt Au__1 = ×_999.9_0.37

100 C C

G

GSt Au__2 = ×_999.9_0.43

100

C St_ 1

C St_ 2

CC St C St

CAu _999.9C

G_0.37

G_0.43

MC St C St

G_100M

C

31


Bracketing calibration

CxC A A C A A

A Ast St X St x St

St St

=− + −

−− − − −

− −

1 2 2 1

2 1

( _ ) ( )_

Cx C

C St− 1

C

C St− 2

C

A St− 1C

A St_ 2C

A X_

Calculation of Au mass fraction (W_‰) in analysed sample

WV

m R

G

GCvials

Px

__

_ . _ ,

= × × ×1

1000

150

0 1

12

0 4

W

V_ 50

L

m_ .0 1

Gvials _12

GP _ .0 4V

R

Combined model equation for calculation of Au content (‰)

W V

m

G

G

C

G

Gvials

P

P_

_ _.

_

.

Au_999.9

_10

_= ×⎛⎝⎜

⎞⎠⎟

× ×1

100050

0 1

12

0 4

00.37 _0.43( _ ) ( )_A A G A A

A A RSt X P X St

St St

2 1

2 1

1− + −( )−

×− −

− −

32


Calculation of signal standard uncertainty estimated as standard deviation

uu

NA

A one set_

_ __=

u A_N

u A one set_ __

N

33


k

PART II. The customer’s requirements concerning quality of the

measurement result

34


T

R

See Part I

MRecovery:CI

Repeatability:

PART III. Validation of the measurement procedure – relevant

equations and measurement data

35


C k

Input

quantityValue Unit

Standard

uncertaintyRemark

V_ 50 50 mL 0.0379 Volume of analysed solution

V_100 100 mL 0.0697 Volume of stock standard solution

m_0.1

0.1001 g 0.0002 Mass of analysed alloy sample

Gvials _12 12.0030 g 0.0008 Mass of sample solution prepared in vials

GP_ .0 4 0.4015 g 0.0009Mass of Au sample solution taken from V

_50

flask

m pureAu_ 0.1004 g 0.0002 Mass weighed of pure gold

Au purity_ 99.99 % 0.0058 The purity of gold stated in the certificate

Gp _0.37

Gp _0.43

0.3701

0.4302g 0.0006

Masses of the stock Au standard solution

transferred for the preparation of calibration

solutions C_St1

and C_St2

G_10 10.0321 g 0.0008 Mass of calibration standard solutions

A St− 1

A St_ 2

0.5203

0.6041AU

0.0010

0.0011

Absorbance measured for calibration

standard solutions

AX 0.5488 AU 0.0011Absorbance measured for the analysed

sample solution

R 1.002 - 0.0025 Recovery

PART IV. Measurement uncertainty of the result – relevant


36


TrainMiC Exercises


Determination of gold in jewellery gold alloys by flame atomic

absorption spectrometry

EXERCISE 1:

Establishing traceability in analytical chemistry

EXERCISE 2:

Single laboratory validation of measurement procedures

Part I: General issues

Part II: Parameters to be validated

Part III: Some calculations and conclusions

EXERCISE 3:


Addendum I: By spreadsheet approach

Addendum II: By dedicated software

The solved exercises ‘green pages’

37


1. Specifying the analyte and measurand

Analyte Gold

Measurand Gold mass fraction in jewellery alloys after aqua regia dissolution

Units ‰ (g/1000 g)

2. Choosing a suitable measurement procedure with associated model equation

Measurement

procedure

Type of calibration standard curve standard addition internal standard

Model equation

1. Standard solutions

1.1. Stock standard solution - prepared from pure gold

Cm Au

GAupureAu purity

_999.9100

=×

×− _

_104

1.2. Calibration standard solutions

C CG

GSt Aup__

1100

= ×_999.9_0.37

C C

G

GSt Aup__

2100

= ×_999.9_0.43

2. Bracketing calibration

CxC A A C A A

A ASt St X St x St

St St

=− + −

−− − − −

− −

1 2 2 1

2 1

( ) ( )_ _

3. Calculation of Au content (W_‰) in analysed sample

WV

m

G

GC

Rvials

Px_

__

_ . _ .

0 = × × ×1

1000

150

0 1

12

0 4

4. Calculation of signal standard uncertainty u

u

NA

A one set_

_ __=

ESTABLISHING TRACEABILITY IN ANALYTICAL CHEMISTRY

EXERCISE

38


5. Calculation of recovery

RW

Wobserved

ref

=

6. Combined model equation for calculation of Au mass fraction (‰)

WV

m

G

G

m Auvials

P

pureAu purity_

_ .

_

_ .

= ×⎛

⎝⎜

⎞

⎠⎟ ×

×−1

100050

0 1

12

0 4 GG V_100 100×× ×

_104

G A A G A A

AP St X P X St_0.37 _0.43×

− + −( )− −

−

( _ ) ( )_ 2 1

SSt StA R2 1

1

−×

−

V _50 L

V _100 L

m_ .0 1

Gvials _12

GP _ .0 4 V

m pureAu_

Au purity_

G or Gp p_0.37 _0.43

G_100

A St− 1 A St_ 2

AX

R

3. List the input quantities according to their influence on the uncertainty of the result of the measurement (first the most important ones). At this point, your judgement should be based on your previous experience only.

1 Recovery – 28.5 % to the expanded uncertainty

2 Absorption of analysed gold sample − contributing 19.8 % to the expanded uncertainty

3 Mass of analysed gold sample − contributing 11.8 % to the expanded uncertainty

39


4Mass of stock solution taken for the preparation of first standard solution − contributing 12.1 % to the

expanded uncertainty

5 Volume of the analysed solution – contributing 3.4 % to the expanded uncertainty

4. List the reference standards needed and give also the information regarding traceability of the reference value

For the analyte

1 Name/Chemical Formula/Producer:Pure Gold − certified by Non-Ferrous Metallurgical

Plant Plovdiv − Bulgaria

2 Name/Chemical Formula/Producer:

For the other input quantities

1Quantity/Equipment/Calibration:

e.g. mass/balance/calibrated by NMI, U = xx

(k = 2), see also data yellow sheet

Balance – calibrated by NMI

2 Quantity/Equipment/Calibration: Volumetric flask − class A quality

3 Quantity/Equipment/Calibration:Absorbance − relative measurement. Not direct part of

the traceability chain.

5. Estimating uncertainty associated with the measurement

Are all important parameters included in the

measurement equation?Yes No

Other important parameters are: Within-lab reproducibility

6. How would you prove traceability of your result?

1 Comparing the results with independent method (cupellation)

40


7. Any other comments, questions…

41


PART I: GENERAL ISSUES

1. Specify the measurement procedure, analyte, measurand and units

The measurement procedure Analysis of gold alloys by AAS

Analyte Gold

The measurandGold in jewellery alloys containing gold 14 ± 0.5 carats after aqua

regia dissolution

Unit ‰

2. Specify the Scope

Matrix Gold in 5 % NH4Cl

Measuring range 37-43 μg g-1

3. Requirement on the measurement procedure

Intended use of the results: Quality of products from precious metals alloys

Mark the customer’s requirements

and give their values

LOD

LOQ

Repeatability

Within-lab reproducibility

Measurement uncertainty 9 ‰

Trueness

Other-state

4. Origin of the measurement procedure

VALIDATION

New in-house method Full

Modified validated method Partial

Official standard method Confirmation/Verification

SINGLE LABORATORY VALIDATION

OF MEASUREMENT PROCEDURES

EXERCISE

42


PART II: PARAMETERS TO BE VALIDATED

5. Selectivity/Interference/Recovery

Where yes, please give further information e.g. which CRM, reference method

CRM/RM: analysis of available CRM or RM

Further information:

Spike of pure substance

Pure gold 99.99 % certified from non-ferrous metallurgical plant Plovdiv, Bulgaria

Compare with a reference method

Comparison with cupellation method

Selectivity, interferences

Test with different matrices

Other – please specify

Test for recovery with RM jewellery gold alloy marked 585

6. Measuring range

Linearity

Upper limit

LOD

LOQ

7. Spread – precision

Repeatability

Reproducibility (within lab)

Reproducibility (between lab)

8. Robustness

Variation of parameters

43


9. Quality control

Control charts

Participation in PT schemes

10. Other parameters to be tested

Working range and testing of homogeneity of variances

Recovery

Residual standard deviation

Standard deviation of the method

Coefficient of variation of the method

44


11. Calculation of parameters requested by the customer

Parameters requested to be

validatedCalculations

LOD

LOQ

Repeatability 2.4 ‰

Within-lab reproducibilty

Trueness

Measurement uncertainty 8.3 ‰ (k = 3)

Other - please state

Recovery1.0002 ± 0.0025

12. Does the analytical procedure fulfil the requirement(s) for the intended use?

ParameterValue requested by the

customer(the same as stated in question 3)

Value obtained

during

validation

The requirement

is fulfilled

Yes/No

LOD

LOQ

Repeatability

Within-lab

reproducibility

Trueness

Measurement

uncertainty9 ‰ (k = 3) 8.3 ‰ (k = 3) yes

Other

The analytical procedure is fit for the intended use:

Yes No

For measurement uncertainty and traceability refer to the corresponding report-sheets

PART III: SOME CALCULATIONS AND CONCLUSIONS

45


BUILDING AN UNCERTAINTY BUDGET

EXERCISE

1. Specify the measurand and units

Measurand Gold mass fraction in jewellery alloys after aqua regia dissolution

Unit ‰ (g/1000 g)

2. Describe the measurement procedure and provide the associated model equation

Measurement procedure:

− T

L L aqua regia

TC C C

L C

T LC

P

Model equation:

1. Concentration of initial standard solution made up from pure gold

Cm Au

GAupureAu purity

9100

99 9410. _

=×

×

C CG

GSt Au__2 = ×_999.9_0.43

100

2. Concentration of calibration standard solutions

C CG

GSt Au__1 = ×_999.9_0.37

100

3. Bracketing calibration

CC A A C A A

A AxSt St X St x St

St St

=− + −

−− − − −

− −

1 2 2 1

2 1

( ) ( )_ _

4. Calculation of Au mass fraction (W_‰) in analysed sample

WV

m R

G

GCvials

Px

_

_ .

_

_ .

= × × ×1

1000

150

0 1

12

0 4

46


5. Calculation of signal standard uncertaintyu

u

NA

A one set_

_ __=

6. Calculation of recovery

RW

Wobserved

ref

=

7. Combined model equation for calculation of Au mass fraction (‰)

W V

m

G

G

C

G

Gvials

P

P_

_ _.

_

.

Au_999.9

_100

= ×⎛⎝⎜

⎞⎠⎟

× ×1

100050

0 1

12

0 4

__0.37 _0.43( _ ) ( )_A A G A A

A A RSt X P X St

St St

2 1

2 1

1− + −( )−

×− −

− −

3. Identify (all possible) sources of uncertainty

Uncertainty of concentration of reference solutions

Uncertainty of measurements of absorption of standard and sample solutions

Mass of analysed gold sample

Volume of the analysed solution

Recovery

Other:

Other:

4. Evaluate values of each input quantity

Input quantity Value Unit Remark

V _5050 mL Volume of analysed solution

V _100100 mL Volume of stock standard solution

m_ .0 10.1001 g Mass of analysed alloy sample

Gvials _1212.0030 g Mass of sample solution prepared in vials

GP _ .0 40.4015 g Mass of Au sample solution taken from V

_50 flask

m pureAu−0.1004 g Mass weighed of pure gold

Au purity_99.99 % The purity of gold stated in the certificate

G Gp p_0.37 _0.43; 0.3701; 0.4302 g



solutions C_St1

and C_St2

47


G_100 10.0321 AU Mass of calibration standard solutions

A St− 1 ; A St_ 2 0.5203; 0.6041 AU

Absorbance measured for calibration standard

solutions

AX 0.5488 AUAbsorbance measured for the analysed sample

solution

R 1.002 - Recovery

5. Evaluate the standard uncertainty of each input quantity

Input quantityStandard

uncertaintyUnit Remark

V _50 0.0379 mL Volume of analysed solution

V _100 0.0697 mL Volume of stock standard solution

m_ .0 1 0.0002 g Mass of analysed alloy sample

Gvials _12 0.0008 g Mass of sample solution prepared in vials

GP _ .0 4 0.0009 g Mass of Au sample solution taken from V_50

flask

m pureAu− 0.0002 g Mass weighed of pure gold

Au purity_ 0.0058 % The purity of gold stated in the certificate

G Gp p_0.37 _0.43; 0.0006; 0.0006 g



solutions C_St1

and C_St2

G_10 0.0008 g Mass of calibration standard solutions

A St− 1; A St_ 2 0.0010; 0.0011 AU

Absorbance measured for calibration standard

solutions

AX 0.0011 AUAbsorbance measured for the analysed sample

solution

R 0.0025 Recovery

6. Calculate the value of the measurand, using the model equation

7. Calculate the combined standard uncertainty (uc) of the result and specify units

Using: M C

48


Input

quantityValue

Standard


W_‰ 583.5 2.8 ‰ Au mass fraction in jewellery alloys

8. Calculate expanded uncertainty (Uc) and specify the coverage factor k and the

units

k

9. Analyse the uncertainty contribution and specify the main three input quantities contributing the most to U

c

1 Recovery – contributing 37.6 % to the expanded uncertainty

2 Absorption of analysed gold sample − contributing 26.1 % to the expanded uncertainty

3 Mass of analysed gold sample − contributing 14.9 % to the expanded uncertainty

10. Prepare your uncertainty budget report

k

k

49


Further readings

I

CI P The Precious Metals Book

I C

I

ICP

R M MFresenius J. Anal. Chem. −

M M L P C P RTM M −

I MI

Protect. Metals −

C L T

Spectrochim. Acta B Atom. Spectrosc. −

M C M R M ICPAtom. Spectrosc. −

LJ. Anal. Atom. Spectrom.

−

T L C

P P Scienti c Works-Chem. −

LICP M Forth

National Conference of Chemistry So a − P

CAnalyst −

50


Addendum I. Measurement uncertainty calculation:

spreadsheet approach (Excel)

51

Chapter 2


Steluta Duta, Philip Taylor


52



Measurand Concentration of calcium in human serum (mg dL-1)


Authors of the example Steluta Duta, Philip Taylor

Analytical procedure Standard WHO procedure

Customer’s requirement Standard WHO procedure


53


II. Attached files

File number, type


File is

attached Remark

Yes No

1 -

I

Ex-10-1-I-

Ca-serum-

Photometry-

2006-Ver1.ppt


lecturer

2 -

Yel

low Ex-10-2-Y-

Ca-serum-

Photometry-

2006-Ver1.doc

PART I Description of the analytical procedure

Each

participant

receives own

copy and

may keep it

PART IIThe customer’s requirements concerning

the quality of the measurement result

PART

III

Validation of the measurement procedure –

relevant equations and measurement data

PART

IV

Measurement uncertainty of the result –

relevant equations and measurement data

3 -

Gre

en Ex-10-3-G-

Ca-serum-

Photometry-

2006-Ver1.doc


chemistry



PART

III

Bulding an uncertainty budget





0 April 2007

1

54




55


56



Determination of concentration of calcium in serum by

molecular absorption spectrometry.

The quality of the results should comply with the requirements

in the WHO procedure

PART I ...................................................................................................................................57


PART II .................................................................................................................................60


PART III ................................................................................................................................61


PART IV ................................................................................................................................62



57



Laboratory task

CI

TT

L

Principle of the measurement method

T − PC C

CT C

MPT


Serum sample preparation and storage

C − °C − °C− °C

Reagents

MPI L MP L

C L

58


CL C L L

TT

L −°C

CStock calcium standard solution C °C

L LL C M L

− °C TL

Calibration calcium standard solutionsT

L LL T

L− °C

Instrumentation

T −T

Experimental protocol

TL

L M L

Blank S5 S7.5 S10 S12.5 Serum QC

Distilled water (mL) 0.1 - - - - - -

Standard (mL) - 0.1 0.1 0.1 0.1 - -

Serum/QC (mL) - - - - - 0.1 0.1

59


Colour reagent (mL) 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Mix well

Buffer solution (mL) 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Mix well

− °C

L

T L I

Calculation of result

T

c A ACa x= ( ) ×−10 10 L

cC −Ax −A− − L

Analytical reliability

I QC

QCQC

C

QC QC

60


Clinical interpretation:1

C − L −C − L −


measurement result according to WHO*

61


Within-laboratory reproducibility (between day precision)

Model equation

C C

CV

c c

n n

c

i obs QC

QC

=

−( )−( )

×

∑ ,2

1

5

1100

CVc QC i i − LcQC QC Ln

Measurement data

Input quantityValue ± standard deviation

(3 replicates)

Mean value ±

standard deviation Unit

ci,obs

(i = 1−5) day

3 replicates/day

1st day: 9.280 ± 0.021

9.16 ± 0.05 mg dL-1

2nd day: 8.990 ± 0.057

3rd day: 9.210 ± 0.105

4th day: 9.230 ± 0.086

5th day: 9.110 ± 0.120

cQC

8.24−10.529.38 ± 0.38

mg dL-1

n 5 no units

CV =



62


IV.1. Preparation of standard solutions2

IV.1.1 Preparation of calcium stock standard solution, cstock

c m M P V Mstock Ca CaCO= × ×( ) × ×( )100 500 3/

c Lm C CMC

P C CV LMC C C C

MInput quantity Value Standard uncertainty Unit

m 625.0 0.2 mg

MCa

40.078 0.002 g mol-1

P 0.9999 0.0058 mass fraction

V500

500.00 0.15 mL

MCaCO3

100.0869 0.0024 g mol-1

IV.1.2 Preparation of calibration standard solutions, ci:

c cV

Vi stocki= ×

⎛⎝⎜

⎞⎠⎟100

c C LVi I Vi V c LV L

Vi V V V V ci = c c c c

PART IV. Measurement uncertainty of the result: relevant

equations and measurement data2

63



cstock

50.05 0.02 mg dL-1

Vi

20.000 0.043 mL

V100

100.000 0.058 mL

IV.2 Calibration – one point calibration

M c

c c A A A Ax x blank blank= −( ) −( )− −10 10/

cx C Lc C L LAx

A LA


c_10

10.000 0.023 mg dL-1

Ax

0.323 0.004 no units

A-10

0.338 0.002 no units

Ablank

0.052 0.004 no units

IV.3 Calculation of calcium concentration in serum sample

c cV

VCa xf= × ⎛

⎝⎜⎞⎠⎟int

cC Lcx LV LV L


cx

9.486 0.303 mg dL-1

Vf

0.100 0.002 mL

Vint

0.100 0.002 mL

64


TrainMiC Exercises


Determination of calcium concentration in human serum by

molecular absorbtion (spectro)photometry

The quality of results should comply with WHO procedure

requirements

EXERCISE 1:


EXERCISE 2:





EXERCISE 3:





65



Analyte Calcium

Measurand Total concentration of calcium in human serum

Units mg dL-1


Measurement

procedure

To determine the calcium concentration in human serum, a serum sub-sample is

mixed with reagent colour and buffer solution, according to WHO standard operation

procedure. The absorbance of calcium calibration solutions and serum sample are

measured by visible spectrophotometry at 540 nm. From the calibration data the

concentration of calcium in human serum is calculated.


Model equation: calcium concentration in serum

c m M P V M V V A ACa Ca CaCO i x blank= × ×( ) × ×( )⎡⎣

⎤⎦ × ( ) × −( )100 500 1003

/ / / AA AV

Vblankf

− −( )⎡⎣ ⎤⎦ × ⎛⎝⎜

⎞⎠⎟10

int

cC LM C CMC

P C CV LMC C C CVi Vi = V c- LV LAx

A LAV LV L


66



1 Matrix effect - recovery

2 Instrumental signal (absorbance)

3 Concentration of standard solutions - purity of CaCO3

4 Volume of the glassware (pipettes, volumetric flasks)

5 Mass

4. List the reference standards needed and state the information regarding traceability of the reference value

For the analyte

1 Name/Chemical Formula/Producer: CaCO3 purity, Merck, min. 99.99 %

2 Name/Chemical Formula/Producer: CaCO3 molar masses/IUPAC





Absorbance/(Spectro)photometer/Calibrated against

traceable optical standard (i.e. PTB)

2 Quantity/Equipment/Calibration:

Volume/Laboratory glassware (pipettes, volumetric

flasks/calibrated by manufacturer (i.e. Hirschmann

Laborgerate )

3 Quantity/Equipment/Calibration:Mass/Analytical balance/calibrated by manufacturer

against traceable mass standards


Are all important parameters included

in the model equation?Yes No

Other important parameters are: Matrix effect

67



1 Via traceable calibration data

2 Via traceable volumetric measurements

3 Via traceable mass measurements


68






The measurement procedure

To determine the calcium concentration in human serum, a serum

sub-sample is mixed with reagent colour and buffer solution,

according to WHO standard operation procedure. The absorbance

of calcium calibration solutions and serum sample are measured by

visible spectrophotometry at 540 nm. From the calibration data the

concentration of calcium in human serum is calculated.

Analyte Calcium

The measurand Total calcium concentration in human serum

Unit mg dL-1

2. Specify the scope

Matrix Human serum

Measuring range 1.0−12.0 mg dL-1


Intended use of the results Calcium concentration in serum result is intended to be used for clinical

interpretation

Mark the customer’s

requirements and give

their values

Parameters to be validated Value requested by the customer

LOD

LOQ

Repeatability

Within-lab reproducibility8 % as CV, by WHO procedure

2 % as CV, the actual state-of-art

Trueness

Measurement

uncertainty

Other-state

69



VALIDATION




70





Further information: ROCHE-Control serum type Precipath U






6. Measuring range

Linearity

Upper limit

LOD

LOQ


Repeatability



8. Robustness



71


9. Quality control

Control charts




R squared


Standard deviation of the analytical procedure

Coefficient of variation of the analytical procedure

Measurement uncertainty

72





LOD

LOQ

Repeatability


CV

c c

n n

c

i obs QC

QC

=

−( )−( )

×

∑ ,2

1

5

1100 = 1.27 %

Trueness




ParameterValue requested by

the customer(the same as stated in question 3)

Value obtained

during validation

The requirement

is fulfilled

Yes/No

LOD

LOQ

Repeatability

Within-lab

reproducibility

8 % as CV, by WHO procedure

2% as CV, the actual state-of-art 1.27 % YES

Trueness

Measurement

uncertainty

Other


Yes No

For measurement uncertainty and traceability refer to the corresponding sheets


73



Measurand Total calcium concentration in human serum

Unit mg dL-1


Measurement procedure

T

T

Model equation: calcium concentration in serum


⎤⎦ × ( ) × −( )100 500 1003

/ / / AA AV

Vblankf

− −( )⎡⎣ ⎤⎦ × ⎛⎝⎜

⎞⎠⎟10

int

cC Lm C CMC

P C CV LMC C C CVi Vi = V c LV LAx

A LAV LV L


74




Uncertainty of measurements of peak area

Method bias

Matrix effect

Other: Uncertainty of absorbance measurements

Other: Uncertainty of volume measurements



m 625.0 mg

MCa

40.078 g mol-1

P 0.9999 mass fraction

V500

500.00 mL

MCaCO3

100.0869 g mol-1

Vi

20.000 mL

V100

100.000 mL

Ax

0.323 no units

A-10

0.338 no units

Ablank

0.052 no units

Vf

0.100 mL

Vint

0.100 mL




m 0.2 mg

MCa

0.002 g mol-1

P 0.0058 mass fraction

V500

0.15 mL

MCaCO3

0.0024 g mol-1

75


Vi

0.043 mL

V100

0.058 mL

Ax

0.004 no units

A-10

0.002 no units

Ablank

0.004 no units

Vf

0.002 mL

Vint

0.002 mL



⎤⎦ × ( ) × −( )100 500 1003

/ / / AA AV

Vblankf

− −( )⎡⎣ ⎤⎦ × ⎛⎝⎜

⎞⎠⎟10

int

cC L


Using: M C

Input quantity ValueStandard


m 625.0 0.2 mg

MCa

40.078 0.002 g mol-1

P 0.9999 0.0058 mass fraction

V500

500.00 0.15 mL

MCaCO3

100.0869 0.0024 g mol-1

Vi

20.000 0.043 mL

V100

100.000 0.058 mL

Ax

0.323 0.004 no units

A-10

0.338 0.002 no units

Ablank

0.052 0.004 no units

Vf

0.100 0.002 mL

Vint

0.100 0.002 mL

u cC

76



units

U(cCa) = k u (cCa) = 0.606 [mg dL-1], k = 2


c

1 Volume serum measurements

2 Concentration of serum sample from calibration data


77


Guide to the Expression of Uncertainty in Measurement M

Eurachem Citac Guide C Qualtifying Uncertainty in Analytical Measurement

C

L RR IM IRMM

CAnalyst −

Further readings

78


Preparation of the standard solution

Addendum I: Measurement uncertainty calculation:


79


80


Calibration

Calculation of calcium concentration in serum sample

Chapter 3

Determination of Radium in Water by a-Spectrometry

Ljudmila Benedik, Urška Repinc, Monika Inkret


81

82



Measurand Activity concentration of Ra-226 in water (Bq L-1) (by α-spectrometry)


Authors of the example Ljudmila Benedik, Urška Repinc, Monika Inkret


Determination of radium isotopes by BaSO4 coprecipitation for the

preparation of alpha-spectrometric sources

J.C. Lozano, F. Fernandez and J.M.G. Gomez, Journal of Radioanalytical and

Nuclear Chemistry 223 (1997) 1−2, 133−137

Customer’s requirementDirective 98/83/EC on the quality of water intended for human

consumption


83


II. Attached files

File number, type and

nameContent of the file

File is

attached Remark

Yes No

1-I EX-08-1-I-Ra226-water-

AS-2006-Ver1.ppt

About the analytical procedure: short

introduction

Given

by the

lecturer

2 -

Yel

low

EX-08-2-Y-Ra226-water-

AS-2006-Ver1.doc

PART IDescription of the analytical

procedure Each

participant

receives

own copy

and may

keep it

PART II



measurement result

PART III


procedure – relevant equations

and measurement data

PART IV

Measurement uncertainty of the

result – relevant equations and

measurement data

3 -

Gre

en

EX-08-3-G-Ra226-water-

AS-2006-Ver1.doc

PART IEstablishing traceability in

analytical chemistry



PART III


Addendum 1: By spreadsheet

approach

Addendum 2: By dedicated

software



0 April 2007

1

84




85


86



87


88



Determination of activity concentration of Ra-226 in drinking

water.


in the revised Directive 98/83/EC on the quality of water

intended for human consumption

PART I ..................................................................................................................... 89


PART II .................................................................................................................... 96


PART III ................................................................................................................... 97


PART IV ................................................................................................................... 98



89


RDetermination of radium isotopes by BaSO4 coprecipitation for the preparation of alpha-spectrometric sourcesC L M

R C 223 − −

1. Scope

1.1 General

T R

− LI

1.2 Interferences

I R

2. Principle

R T


90


Figure 4. Experimental protocol for determination Ra-226 in water

3. Apparatus

Pd = 0.001

C L

M

P

P

91


4. Reagents

M kR I T RM

k

k

P LL

M T M

I −

5. Sample preparation procedure

The radiochemical separation procedure of Ra-226 with lead coprecipitation

M L1000 mL ± 5 mL L R ®

LL

P P R LP−

R

L

PR

M Q

PL M T M

− PLL

92


R

RM

6. Preparation of standard discs

6.1 Preparation of a Ba-133 standard disc

I

M L

L

L PCP

PL M T M

−LL

M

M

T

T

93


6.2 Preparation of a Ra-226 standard disc

RT

R

M L R

L

L PCP

PL M T M

−LL

M

M

7. Preparation of blank filters

7.1 Preparation of blank filter

RM

7.2 Making a reagent blank filter

R

−

94


8. Gamma and alpha counting

GammaMMM

AlphaMMMM RM R

9. Calculation

9.1 Sample recovery calculation

RP

t m

tchem

Ba-133sample

Ba-133sample Ba-133sample

Ba-133St

=

×× dd Ba-133Std

Ba-133Std

× m

P

RPtmPtm

P

t m A RRa-226Std

Ra-226Std Ra-226SS Ra-226SS Ra-226Std

=× × ×

9.2 Alpha spectrometer efficiency determination

RRPR RtRmR RAR R

95


9.3 Activity concentration of Ra-226 in the sample (Bq L-1)

AP

t e V RRa-226Ra-226

Ra-226 det sample chem

=× × ×α

AR R LPR RtRV L

R

96


Extract from the Directive 98/83/EC, Draft annex 2005/04/20 on the

quality of water intended for human consumption

Reference concentration for radioactivity in drinking water*

Origin Nuclide Reference concentration

Natural Ra-226 0.5 Bq L-1

This table includes the most common natural and arti cial radionuclide Reference concentrations for other radionuclides can be calculated using the dose coef cients for adults laid down in Annex III Table A of Directive 96/29/Euratom or more recent information recognised by the competent authorities in the Member State, and by assuming an intake of 730 litres per year.

Performance characteristics and methods of analysis

Parameter Limit of detection Notes

Ra-226 0.04 Bq L-1Note 1

Note 2

Note 1: the limit of detection should be calculated according to ISO 11929-7, Determination of the detection limit and decision thresholds for ionizing radiation measurements - Part 7: Fundamentals and general applications, with probabilities of errors of 1st and 2nd kind of 0.05 eachNote 2: measurement uncertainties should be calculated and reported as complete standard uncertainties, or as expanded standard uncertainties with an expansion factor of 1.96, according to the ISO Guide for the Expression of Uncertainty in Measurement (ISO, Geneva 1993, corrected reprint Geneva, 1995)


measurement result

97


IR

I

L

L LL

Equation

LLDBkg

Bkg chem sample

=+

× × ×2 71 4 65. .

dett R Vεα

Measurement data

Input quantity Unit Value

Rchem

radiochemical yield (recovery) - 0.803

εα det

efficiency of alpha detector - 0.2453

Bkg peak area of background of alpha detector at the Ra-226 alpha energy -

tBkg

time of measurement of background s

Vsample

volume of the sample L



98


IR R

TT

T

I

Equations

( )u A

A

u P

P

u ee

Ra-226

Ra-226

Ra-226

Ra-226

2

det

αdet

( )( )=

⎛⎝⎜

⎞⎠⎟

+⎛

⎝α

⎜⎜⎞

⎠⎟+

⎛

⎝⎜

⎞

⎠⎟ +

⎛⎝⎜

⎞⎠⎟

2

sample

sample

2

chem

chem

2( ) ( )u V

V

u R

R

u R

R

u P

P

u mchem

chem

Ba-133Std

Ba-133Std

2

Ba-133Std( ) ( )( )=

⎛

⎝⎜

⎞

⎠⎟ +

mm

u P

PBa-133Std

2

Ba-133sample

Ba-133sample

2

⎛

⎝⎜

⎞

⎠⎟ +

( )⎛

⎝⎜⎜

⎞

⎠⎟⎟

+uu m

m

Ba-133sample

Ba-133sample

2( )⎛

⎝⎜⎜

⎞

⎠⎟⎟

u ee

u P

P

u m

mα

α

det

det

Ra-226Std

Ra-226Std

2

Ra-226SS( ) ( )( )=

⎛⎝⎜

⎞⎠⎟

+RRa-226SS

2

Ra-226SS

Ra-226SS

2

Ra-226Std( )⎛⎝⎜

⎞⎠⎟

+⎛⎝⎜

⎞⎠⎟

+u A

A

u R( ))

RRa-226Std

2⎛⎝⎜

⎞⎠⎟

u A k A( ) ( )Ra-226 Ra-226= ×



99


Mea

sure

men

t d

ata

Inp

ut

qu

anti

tyU

nit

Val

ue

Stan

dar

d

un

cert

ain

ty

Typ

e o

f

un

cert

ain

tyTy

pe

of

dis

trib

uti

on

(u)

no

rmal

rect

ang

ula

rtr

ian

gu

lar

V sam

ple

volu

me

of t

he

sam

ple

L1.

00.

002

BX

mB

a-1

33

sam

ple

mas

s o

f ad

ded

Ba-

133

in t

he

sam

ple

g0.

301

0.00

1B

X

mB

a-1

33

Std

mas

s o

f ad

ded

Ba-

133

in b

ariu

m

stan

dar

d d

isc

g0.

112

0.00

1B

X

mR

a-2

26

SS

mas

s o

f ad

ded

Ra-

226

in s

tan

dar

d

solu

tio

ng

0.01

00.

001

BX

A Ra-

22

6 S

Sac

tivi

ty c

on

cen

trat

ion

of R

a-22

6 in

stan

dar

d s

olu

tio

nB

q g

-127

29-

BX

t Ra-

22

6ti

me

of m

easu

rem

ent

s30

0 00

0-

--

t Ba-

13

3 s

amp

leti

me

of t

he

sam

ple

mea

sure

men

t (s

)s

3000

--

-

t Ba-

13

3St

dti

me

of m

easu

rem

ent

of B

a-13

3 in

bar

ium

sta

nd

ard

dis

cs

3000

--

-

P Ra-

22

6p

eak

area

of R

a-22

6-

7516

87A

X

P Ba-

13

3 s

amp

lep

eak

area

of B

a-13

3 in

th

e sa

mp

le-

10 9

1410

4A

X

P Ba-

13

3 S

tdp

eak

area

of B

a-13

3 in

bar

ium

stan

dar

d d

isc

-50

9071

AX

P Ra-

22

6 S

tdp

eak

area

of R

a-22

6 in

sta

nd

ard

dis

c-

12 7

8511

3A

X

R chem

rad

ioch

emic

al y

ield

(rec

ove

ry)

--

-A

X

ε α d

eteffi

cien

cy o

f alp

ha

det

ecto

r-

--

AX

R Ra

-22

6S

td

rad

ium

sta

nd

ard

dis

c re

cove

ry-

--

A

X

100


TrainMiC Exercises


Determination of activity concentration of Ra-226 in drinking

water.

The quality of the results should comply with the requirement

in the revised Directive 98/83/EC on the quality of water

intended for human consumption

EXERCISE 1:


EXERCISE 2:





EXERCISE 3:





101




Analyte Ra-226

Measurand Activity concentration of Ra-226 in water (drinking, surface, waste, …)

Units Bq L-1


Measurement

procedure

Determination of radium isotopes by BaSO4 coprecipitation for the preparation of

alpha-spectrometrical sources

Lozano et al., Journal of Radioanalytical and Nuclear Chemistry

Type of calibration mixed standard source standard addition internal standard

Model equation

T R L

AP

t e V RRa-226Ra-226


=× × ×α

AR R LPR RtRV L

R

RP

t m

tchem

Ba-133sample


Ba-133Std=×

××× m

PBa-133Std

Ba-133Std

R

RPtmP

102


tm

P

t m A RRa-226Std


=× × ×

RRPR RtR RmR RAR R


1 Uncertainty of concentration of reference solutions

2 Uncertainty of volumes

3 Uncertainty of weighing

4 Uncertainty of measurement, using alpha and gamma detectors


For the analyte

1 Name/Chemical Formula/Producer: Standard Radionuclide Source, Analytics, SRS 67978-121

2 Name/Chemical Formula/Producer:Ba-133 standard solution, Czech Metrological Institute,

Cert. No: 931-OL-137/99

2 Name/Chemical Formula/Producer: Ra-226 standard solution, NIST SRM 4967

103





(k = 2) see also data yellow sheet

Graduated and mixing cylinders, volumetric flask/with

established traceability

BLAUBRAND® tolerance

2 Quantity/Equipment/Calibration:Mass/calibrated balance/with established traceability

Sartorius



model equation?Yes No

Other important parameters are:

Uncertainty of measured background of detector,

uncertainty of measured blank reagents (minor

contributions)


1 Analysis of matrix CRM

2 Participation in a proficiency testing scheme

3 -


104




The measurement

procedure

Determination of radium isotopes by BaSO4 coprecipitation for the preparation of

alpha-spectrometric sources

J.C. Lozano, F. Fernandez and J.M.G. Gomez

Journal of Radioanalytical and Nuclear Chemistry 223 (1997) 1−2, 133−137.

Analyte Ra-226

The measurand Activity concentration of Ra-226 in drinking water

Unit Bq L-1


Matrix Drinking water

Measuring range 0.01–10 Bq L-1


Intended use of the results Compliance to the requirements in the revised water directive 98/83/EC on

the quality of water intended for human consumption



their values


LOD 0.04 Bq L-1

LOQ

Repeatability


Trueness


Other-state


VALIDATION






105







spiking of samples with pure substances and calculation of recovery





6. Measuring range

Linearity

Upper limit

LOD

LOQ


Repeatability




106


8. Robustness


9. Quality control

Control charts




R square





107



Parameters requested to

be validatedCalculations

LODLLD =

+× × ×

=2 71 4 65 14 26092744

420 730 0 2453 0 803 10 000245

. . .

. ..

Bq L-1

LOQ

Repeatability


Trueness






Value obtained

during validation

The requirement

is fulfilled

Yes/No

LOD 0.04 Bq L-1 0.00025 Bq L-1 YES

LOQ

Repeatability

Within-lab

reproducibility

Trueness

Measurement

uncertainty

Other


Yes No



108



Measurand Activity concentration of Ra-226 in water (drinking, surface, waste, …)

Unit Bq L-1



C L MR C 223 − −

Model equation:

T R L

AP

t V RRa-226Ra-226


=× × ×α

AR R LPR RtRV L

R


109


R

RP

t m

tchem

Ba-133sample


Ba-133Std=×

×× mm

PBa-133Std

Ba-133Std

RP PtmPtm

P

t m A RRa-226Std


=× × ×

RRPR RtR RmR RAR R



Uncertainty of measurements of peak area (alpha and gamma detectors)

Method bias

Matrix effect

Other: Uncertainty of volume measurements

Other: Uncertainty of weighing

Other: Uncertainty of measured background of alpha and gamma detectors

Other: Uncertainty of measured blank reagents, filters, discs

110




PRa-226

7516 -

tRa-226

300 000 s

εαdet

0.2453 -

Vsample

1.0 L

Rchem

0.803 -




PRa-226

87 -

tRa-226

0 s Constant

εαdet

0.01392 -

Vsample

0.0020 L

Rchem

0.0142 -


AP

t e V RRa-226Ra-226

Ra 226 det sample chem

1=

× ××

− α

A Ra-226-17516

300 000 0.2453 1

1

0.803Bq L=

× ×× = 0 127.

7. Calculate the combined standard uncertainty (uc ) of the result and specify units

Using: M C

Input quantity ValueStandard


PRa-226

7516 87 -

tRa-226

300 000 0 s

εαdet

0.2453 0.01392 -

111


Vsample

1.0 0.0020 L

Rchem

0.803 0.0142 -

( )u A

A

u P

P

u ee

Ra-226

Ra-226

Ra-226

Ra-226

2

det

αdet

( )( )=

⎛⎝⎜

⎞⎠⎟

+⎛

⎝α

⎜⎜⎞

⎠⎟+

⎛

⎝⎜

⎞

⎠⎟ +

⎛⎝⎜

⎞⎠⎟

2

sample

sample

2

chem

chem

2( ( )u V

V

u R

R

)

u A

ARa-226

Ra-226

2 287

7516

0.01392

0

0.002( )= ⎛

⎝⎜⎞⎠⎟

+ ⎛⎝⎜

⎞⎠⎟

+.2453

00

1

0.0142

0.803

2 2⎛⎝⎜

⎞⎠⎟

+ ⎛⎝⎜

⎞⎠⎟

= 0 00806.


units

u A k A( ) ( )Ra-226 Ra-226= ×

U = × =2 0.00806 0.016 Bq L-1

9. Analyse the uncertainty contribution and specify the main three input quantities contributing the most to u

c

1 Mass of Ra-226 standard solution

2 Peak area of Ba-133 in the standard disc

3 Peak area of Ra-226 of the sample


See the attached Excel calculations and calculations done using the software GumWorkbench

112


C COf c. J. Eur. Commun. L

C C C TOf c. J. Eur. Commun. L

R T M C RR

Of c. J. Eur. Commun. L

R T M C R R T MOf c. J. Eur. Commun. L

Guidelines for Drinking Water Quality, Recommendation

Guidelines for Drinking Water Quality, Recommendation

C L MJ. Radioanalyt.

Nucl. Chem. − −

P L RActa. Chim. Slov.

−

L MR C Proceedings of the 7th

International Conference on Nuclear and Radiochemistry RC

Further readings

113


Ad

de

nd

um

I: M

ea

sure

me

nt

un

cert

ain

ty c

alc

ula

tio

n, s

pre

ad

she

et

ap

pro

ach

(E

xce

l)

114


115


e α

116


117


Model equation:

AR = PR tR × εα × V × RR P × m × t × m Pεα = PR tR × mR × AR × RR

List of quantities:

Quantity Unit Definition

ARa-266

Bq L-1 Activity of Ra-266 in sample

PRa-266

Area of Ra-266

tRa-266

s Time of measurement

eαdetEfficiency for alfa detector

Vsample

L Volume of the sample

Rchem

Radiochemical yield (recovery)

PBa-133sample

Area of Ba-133 in sample

tBa-133sample

s Time of measurement of the sample

mBa-133sample

g Mass of Ba-133 in the sample

tBa-133Std

s Time of measurement of Ba-133 standard disc

mBa-133Std

g Mass of Ba-133 standard disc

PBa-133Std

Area of Ba-133 in standard disc

PRa-226Std

Area of Ra-266 in standard disc

tRa-226Std

s Time of measurement of the standard disc

mRa-226SS

g Mass of Ra-226 standard solution

ARa-226SS

Activity of Ra-226 in standard solution

RRa-226Std

Radium standard disc recovery

PRa-266:TM

tRa-266:C

Addendum II: Measurement uncertainty calculation –

GumWorkbench

118


Vsample:T

LL

PBa-133sample:TM

tBa-133sample:C

mBa-133sample:T

tBa-133Std:C

mBa-133Std:T

PBa-133Std:TM

PRa-226Std:TM

tRa-226Std:C

119


mRa-226SS:T

ARa-226SS:TM

RRa-226Std:TM

Uncertainty budgets:

ARa-266: Activity of Ra-266 in sample

Quantity ValueStandard

UncertaintyDistribution

Sensitivity

Coefficient

Uncertainty

ContributionIndex

PRa-266

7516.0 86.0 normal 17 × 10-6 1.5 × 10-3 Bq L-1 3.3 %

tRa-266

300.0 × 103 s

Vsample

1.00000 L 2.04 × 10-3 L triangular -0.13 -260 × 10-6 Bq L-1 0.1 %

PBa-133sample

10 914 104 normal -12 × 10-6 -1.2 × 10-3 Bq L-1 2.3 %

tBa-133sample

3000.0 s

mBa-133sample

0.301200 g 577 × 10-6 g rectangular 0.42 240 × 10-6 Bq L-1 0.0 %

tBa-133Std

3000.0 s

mBa-133Std

0.112800 g 577 × 10-6 g rectangular -1.1 -650 × 10-6 Bq L-1 0.7 %

PBa-133Std

5090.0 71.0 normal 25 × 10-6 1.8 × 10-3 Bq L-1 4.9 %

PRa-226Std

12785 113 normal -9.9 × 10-6 -1.1 × 10-3 Bq L-1 2.0 %

tRa-226Std

2000.0 s

mRa-226SS

0.010220 g 577 × 10-6 g rectangular 12 7.2 × 10-3 Bq L-1 79.9 %

ARa-226SS

2729.0 10.7 normal 47 × 10-6 500 × 10-6 Bq L-1 0.4 %

RRa-226Std

0.9344 0.0150 normal 0.14 2.0 × 10-3 Bq L-1 6.5 %

ARa-266

0.12719 Bq L-1 8.04 × 10-3 Bq L-1

120


εαdet: Ef ciency of alfa detector



Sensitivity

Coefficient

Uncertainty

ContributionIndex

PRa-226Std

12 785 113 normal 19 × 10-6 2.2 × 10-3 2.2 %

tRa-226Std

2000.0 s

mRa-226SS

0.010220 g 577 × 10-6 g rectangular not valid! -0.014 90.1 %

ARa-226SS

2729.0 10.7 normal -90 × 10-6 -960 × 10-6 0.4 %

RRa-226Std

0.9344 0.0150 normal -0.26 -3.9 × 10-3 7.2 %

eαdet0.2453 0.0146

Rchem: Radiochemical yield (recovery)



Sensitivity

Coefficient

Uncertainty

ContributionIndex

PBa-133sample

10 914 104 normal 74 × 10-6 7.7 × 10-3 28.8 %

tBa-133sample

3000.0 s

mBa-133sample

0.301200 g 577 × 10-6 g rectangular -2.7 -1.5 × 10-3 1.2 %

tBa-133Std

3000.0 s

mBa-133Std

0.112800 g 577 × 10-6 g rectangular 7.1 4.1 × 10-3 8.3 %

PBa-133Std

5090.0 71.0 normal -160 × 10-6 -0.011 61.7 %

Rchem

0.8030 0.0143

Result:

Quantity ValueExpanded

UncertaintyCoverage factor Coverage

ARa-266

0.127 Bq L-1 0.016 Bq L-1 2.00 95 %

121

Chapter 4


Allan Künnapas, Koit Herodes, Ivo Leito

TrainMiC example summary form (’blue page’) A short introduction to the analytical procedure (’slides’) All input needed to do the three exercises (’yellow pages’) The solved exercises (’green pages’)

122




MeasurandConcentration of imazalil and thiabendazole in tangerines by liquid

chromatography-mass spectrometry


Authors of the example Allan Künnapas, Koit Herodes, Ivo Leito


Determination of concentration of imazalil and thiabendazole in

tangerines by liquid chromatography-mass spectrometry. The sample

preparation procedure is modified AOAC 985.22 procedure. The

measurement procedure is an in-house developed procedure.

Customer’s requirementThe quality of the results should comply with the requirements given

in the EU Directives 93/58/EEC and 00/42/EEC on pesticide residues

analysis

123


File number,

type and nameContent of the file

File is

attached Remark

Yes No

1 -

I

Ex-04-1-I-

Pesticides-

Food-LCMS-

2006-Ver1.ppt


leacturer

2 -

Yel

low Ex-04-2-Y-

Pesticides-

Food-LCMS-

2006-Ver1.doc

PART I Description of the analytical procedureEach

participant

receives own

copy and may

keep it

PART IIThe customer’s requirements concerning

the quality of the measurement result

PART III



measurement data

PART IV

Measurement uncertainty of the result

– relevant equations and measurement

data

3 -

Gre

en Ex-04-3-G-

Pesticides-

Food-LCMS-

2006-Ver1.doc


chemistry



PART III






0 April 2007 -

1

II. Attached files

Determination of Polar Pesticides by Liquid

124




125


126



127


128




Determination of concentration of imazalil and thiabendazole

in tangerines by liquid chromatography mass spectrometry.


in the EU directives 93/58/EEC and 00/42/EEC/ on pesticide

residues analysis

PART I ............................................................................................................................... 129


PART II .............................................................................................................................. 133

The customer’s requirement concerning quality of the measurement result

PART III ............................................................................................................................. 135


PART IV ............................................................................................................................ 137


129



TM R L MRL

C C

CLC M

1. Scope

C LC MM T

P I LC M M

I

2. Principle

CC

TT LC M

I LC MM

TL I

M MC

T

130


Laboratory sample is homogenized using appropriate equipment

50 g aliquot of homogenized sample is extracted with 100 mL of acetone using high speed blender. Before the extraction standard solution can be added for recovery studies

Mixture is vacuum filtered through filter paper, the extraction vessel is rinsed and filter cake is washed with approximately 30 mL of acetone

The volume of the extract is measured and a 50 mL aliquot is taken for further purification through liquid-liquid extraction

In a separatory funnel the aliquot is extracted for 1 min with 100 mL of petroleum ether and dichloromethane mixture (1:1)

The lower (water) phase is drained into volumetric cylinder, the upper organic layer is filtered/dried through approximately 3 cm layer of anhydrous Na2SO4 in a funnel

The water phase is saturated in the separatory funnel with NaCl and extracted twice for 1 min with 50 mL of dichloromethane. The lower (organic) layer is also

filtered/dried through the same Na2SO4 layer

The combined extract is brought down to couple of millilitres using rotary evaporator, taking care not to evaporate to dryness

The extract is brought to almost complete dryness in slow flow of N2, then the residue is reconstituted with 10 mL of methanol

If necessary the extracts are diluted in order to fit in the calibration range

Figure 5. Flow chart of the analytical procedure

131


3. Interferences

I TT

I

T

4. Reagents

1000 mg kg-1 individual pesticide standard solutionsP

L

20 mg kg-1 combined pesticide standard solutionL

Calibration solutions

Solvents/eluent:

LC MC PLC

Other:C

5. Sampling and pre-treatment

CC

132


6. Calculation

T ww

ww V V

V m=

× × ××

c e10

50

ρ

w

wV L

LVe e e e e e LV e e e e e e e Lm e e e e e e

7. Results

C e e e e e e ee e e e e MRL e C

e e T e e e MRL e e e e ee

133


PART II. The customer’s requirement concerning quality of the

measurement result

T e e e e L e e e eI e e CT e e e e C

Extract from the EU Quality Control Procedures for Pesticide Residues Analysis, SANCO/10232/2006

T e e e e e e e e e e e ee e e T e e e e e e e e e ee e e e e e e e ee e

Me e e e e I e e e ee e

e e e e e e e e ee e e e e e e e

e e e e e e e e e e e ee e eI e e e e e e e e

e MRL

I M M M e e e e e e ee e I e e e ee e e e CI PI e e e

e e e e e e e e I e e e ee e e e e e

e e e e e e e e e e e

e e e ee e e e

M Me e M

e e LC M

134


Table 3. Recommended maximum permitted tolerances for relative ion intensities using a range of spectrometric techniques

Relative intensity

(% of base peak)

EI-GC-MS

(relative)

CI-GC-MS, GC-MSn, LC-MS, LC-MSn

(relative)

>50 % ±10 % ±20 %

>20−50 % ±15 % ±25 %

>10−20 % ±20 % ±30 %

≤ 10 % ±50 % ±50 %

135




Equations

Rw

w

STDEVn x x

n n

AVERAGEx

n

RSDSTD

= ×

=− ( )−

=

=

∑ ∑

∑

exp %

( )

theor

100

1

2 2

EEV

AVERAGE×100 %

we e e e e e e e e e e ee e e e e e e e e e ee e

w e e e e e e e e e ee e

n e e e e

x I e x e e R e e

STDEV e

AVERAGE e e e e e

RSD e e e

136


Measurement data

Imazalil Thiabendazole ImazalilThiaben-

dazole

wexp

(mg kg-1)

wtheor

(mg kg-1)

R

(%)

wexp

(mg kg-1)

wtheor

(mg kg-1)

R

(%)Peak area Peak area

0.06427 0.05597 0.03120 0.04244 3 996 669 300 802

0.07516 0.05871 0.03281 0.04452 3 459 066 281 164

0.04812 0.05821 0.03181 0.04413 3 838 651 230 775

0.10238 0.07342 0.04095 0.05567 3 727 188 274 366

0.04201 0.06088 0.03400 0.04616 3 414 893 296 724

0.05741 0.06241 0.03331 0.04732 3 553 740 258 916

AVERAGE recovery AVERAGE recovery AVERAGE mass fraction

STDEV of recovery STDEV of recovery STDEV of mass fraction

RSD of recovery (urel_rec

) RSD of recovery (urel_rec

) RSD of mass fraction

(urel_meth

)

* The recovery determinations were carried out two per day on three consecutive days.

137




Equations

u u u

uu u

w

d w w

u

w

= +

=+

×

= −

sys rnd

rnd

rel_rec rel_meth

ref

ref

2 2

2 2

100 %

==

=

= +

s

n

ud

n

u u u

1

2

2 2

dev

sys ref dev

u e e eu e e eu e eu e e e e e e eu e e e e e ew e e e e e e e e

e ed e e e e ee e e e e e

w e e e e e e e e e e e e e

s e e e e e e e

n e e e eILC

n e e e ILC

u e e e e e e e e ee e e e e

u e e e e e e e e

138


Measurement data

Imazalil Thiabendazole Comments

urel_rec

27 % 2 %

The relative standard deviation of recovery

calculated from parallel measurement results (two

measurements per day on three consecutive days)

urel_meth

10 % 6 %

The relative standard deviation of results obtained

for the same solution from repeated injections of

the same solution

w 1.3350 mg kg-1 3.5230 mg kg-1

wref

1.2975 mg kg-1 3.2863 mg kg-1 consensus value of interlaboratory comparison

measurement

s 0.0530 mg kg-1 0.5571 mg kg-1

nl

2 3

n 1 1

139



TrainMiC Exercises


Determination of concentration of imazalil and thiabendazole

in tangerines by liquid chromatography-mass spectrometry.


in pesticide residues analysis directives and guidelines

EXERCISE 1:


EXERCISE 2:





EXERCISE 3:


Addendum I. By spreadsheet approach

Addendum II. By dedicated software

140




Analyte Residues of imazalil and thiabendazole

Measurand Acetone-extractable imazalil and thiabendazole residues in tangerines

Units mg kg-1 (ppm)


Measurement

procedure

50 g of homogenized sample is extracted with 100 mL of acetone using high speed

blender. Mixture is filtered and the volume of extract is measured.

50 mL of the extract is extracted with 100 mL dichloromethane petroleum ether

mixture (1:1), the organic layer is filtered through a layer of sodium sulphate (for

drying purpose). Water phase is saturated with NaCl and extracted twice with 50

mL of dichloromethane. Organic extracts are dried as before. Solvent is evaporated

to almost dryness and the sample is dissolved in 10−20 mL of methanol. Sample is

filtered through a syringe filter and analysed using LC-MS system.

Sample preparation procedure is based on the AOAC official method 985.22

‘Organochlorine and Organophosphorus Pesticide Residues Gas Chromatographic

Method’. The modifications were made in order to cut down sample size and thus

solvent consumption. Also changes were made in the solvent of final extract to suite

LC-MS system. LC-MS analysis method was developed within laboratory.

Type of calibration standard curve Standard addition internal standard

Model equation

ww V V

V m=

× × ××

c e10

50

ρ

w e e e e e e e ee

w e e e e e ee e

V e e e e Lρ e e LVe e e e e e LV e e e e e e e Lm e e e e e e

141



1 Mass fraction of extractable pesticide in analysed extract (wc, mg kg-1)

2 The full volume of acetone extract (Ve, mL)

3 The volume of final extract in methanol (V10

, mL)

4 The volume of acetone extract to be purified (V50

, mL)

5 The density of methanol (ρ, g mL-1)

6 The mass of homogenized sample (m, g)


For the analyte

1Name/ChemicalFormula/

Producer:

Imazalil (solid substance)/C14

H14

Cl2N

2O/Dr. Ehrenstorfer

Value including uncertainty (with units):

Imazalil: purity 97.5 % (tolerance ±0.5 %) (data obtained from

corresponding Certificate of Analysis)

2Name/ChemicalFormula/

Producer:

Thiabendazole (solid substance)/C10

H7N

3S/Dr. Ehrenstorfer

Value including uncertainty (with units):

Thiabendazole: purity 99.0 % (tolerance ±0.5 %) (data obtained from

corresponding Certificate of Analysis)


1Quantity/Equipment/Calibration:e.g. mass/balance/calibrated by NMI, U = xx


None


Are all important parameters included in the model

equation?Yes No



1 Participate in EU proficiency testing programme

2 Analyse a CRM (in future, when such CRM becomes available)

142



143


SINGLE LABORATORY VALIDATION OF

MEASUREMENT PROCEDURES



The measurement

procedure

Sample preparation procedure is modified AOAC official method 985.22. Analysis

was carried out on an LC-MS system using a self-developed chromatographic

method.

Analyte Residues of imazalil and thiabendazole (polar basic pesticides)

The measurand

Acetone-extractable pesticides in tangerines.

Results are not recovery corrected, thus extractable pesticides are determined, not

total amounts.

Unit mg kg-1 (ppm)


Matrix Tangerines

Measuring rangeimazalil 0.004–0.9 mg kg-1

thiabendazole 0.003–0.7 mg kg-1


Intended use of the results

Post-registration control and monitoring of pesticides based on MRLs set by

the EU Directives 93/58/EEC and 00/42/EEC for imazalil and thiabendazole

respectively.


requirements and give their

values


LODLOD < 0.02 mg kg-1 (imazalil), LOD < 0.05

mg kg-1 (thiabendazole)

LOQ

Repeatability

Within-lab

reproducibility

Trueness Recovery between 70–110 %

Measurement

uncertainty

Oth

er -

sta

te

Identity/confirmation: retention time (compared with

standard) + MS^2 fragmentation: imazalil (297 → 201),

thiabendazole (202 → 175) + additional qualifier ion

comparison if necessary. Guidance document refers to

sufficient confirmation when MS^2 is used and ion ratios in

standard and sample agree within the limits specified in

Table 3 (Yellow sheet, Part II).

144



VALIDATION




145








At approximate concentration level of 0.05 mg kg-1



Chromatographic separation and mass-spectrometric identification (including MS^2 confirmation of

identity)


The method has been proved via ILC to perform with tangerine, orange and tomato


Confirmation of identity: chromatographic retention time and MS^2 confirmation of identity

6. Measuring range

Linearity

Imazalil: 0.004–0.9 mg kg-1; Thiabendazole: 0.003–0.7 mg kg-1

Upper limit

Imazalil: 0.9 mg kg-1; Thiabendazole: 0.7 mg kg-1

LOD

Imazalil: 0.004 mg kg-1; Thiabendazole: 0.003 mg kg-1

LOQ


Repeatability

Instrumental: standard deviation of the measurement method: 10 % for imazalil and 6 % for

thiabendazole (repeated injection of the same standard solution).

Reproducibility (within Lab)

Full procedure: standard deviation of recovery experiments carried out on three consecutive days –

27 % for imazalil, 2 % for thiabendazole (full sample preparation included )

Reproducibility (between Lab)

in ILC the difference between results were 5.6 and 4.4 % for imazalil and thiabendazole respectively

146


8. Robustness


Variation of some of the parameters: during method development two different columns were used

(C18 250 ¥ 4.6 5μ, C18 150 ¥ 150 2.1), mobile phase composition and velocity were changed in

increments and obtained data analysedd, final extract volumes of 10 and 20 mL were utilized.

9. Quality control

Control charts




R square





Other-state: Confirmation of identity: in accordance with requirements in Section 3.

147




Parameters requested

to be validatedCalculations

LOD

Since the method permits in principle to obtain significantly lower LOD values

than requested by the customer, LOD was estimated in a conservative way by

taking the lowest points on the respective calibration graphs as LOD estimates.

Values obtained:

Imazalil: 0.004 mg kg-1

Thiabendazole: 0.003 mg kg-1

LOQ

Repeatability

Within-lab

reproducibility

Trueness

Average recovery; for data and equations see first document

Imazalil 104 %

Thiabendazole 73 %

Recovery is found according to the following equation:

Rw

w= ×exp %

theor

100

R – recovery of the method [%]

wexp

– experimentally measured mass fraction of the pesticide residue in

the sample, in recovery studies the pesticide sis spiked into the sample

homogenate [mg kg-1]

wtheor

– theoretically calculated mass fraction of the pesticide residues in the

spiked sample [mg kg-1]

Measurement

uncertainty

Other - please

state

148





Value obtained

during validation

The requirement

is fulfilled

Yes/No

LODImazalil < 0.02 mg kg-1

Thiabendazole < 0.05 mg kg-1

0.004 mg kg-1

0.003 mg kg-1

Yes

Yes

LOQ

Repeatability

Within-lab

reproducibility

Trueness 70–110 %Imazalil 104 %

Thiabendazole 73 %

Yes

Yes

Measurement

OtherConfirmation based on similarity to

standard (MS^2 spectrum)

MS^2 spectrum in

sample is similar to

standard

Yes


Yes No


149




Measurand Extractable pesticide content in fruit/vegetable

Unit mg kg-1



e e e e e L e e ee e eM e e e e e e e e L e e e

L e e e e e e − C e ee e e e e e e e

C e e e L e e e ee e e e e e e e e e− L e e e e e e e e ee e e e e e e eLC M e

e e e e e C ee LC M e e e e e e

Model equation

ww V V

V m=

× × ××

c e10

50

ρ

w e e ew e e e eV e e e e Lρ e e LVe e e e e e LV e e e e e e e Lm e e e e e e

150


e e e e e e I e ee e e e e e e I e e e e

e e e e e e e

T e e

u u uw sys rnd= +2 2

u e e eu e e eu e e

T e e e ee u e e e e e eI e e e e u bias T e

CRM ILCe u e e e e e ee

e I e e e e u R T ee e ee e e e e

T e e u e

u u uw = +dev ref2 2

e e u e e e e e e e e e ee e e e e e e e RMS e e u e e e

e e e e e e e e e e u e e e

T e e e e e ee

e Re TR C Me e e ee L e M T M e e

e e e e e e

151


uu u

w

d w w

us

n

ud

n

rnd

rel_rec rel_meth

ref

ref

1

dev

=+

×

= −

=

=

2 2

2

100 %

u e e e e e e e

u e e e e e e

w e e e e e e e e e e ee e e e e

w e e e e e e e e e e e e e

d e e e e ee e e e e e

s e e e e e e en e e e ILC

n e e e ILC n eu e e e e e e e e e

e e e e eu e e e e e e e e




Method bias

Matrix effect: matrix effects on ionisation of pesticides (repeatability)

Other: repeatability of extraction of the pesticides

Other: stability of standard solutions, integration

Other: calibration graph linearity

152



Input

quantity

ValueUnit Remark

Imazalil Thiabendazole

wc

2.801 7.398 mg kg-1 Mass fraction of residue in extract, calculated based

on calibration

V10

10 10 mL Volume of final methanol extract

ρ 0.791 0.791 g mL-1 Density of methanol

Ve

150 150 mL Volume of extract after filtration

V50

50 50 mL Volume of extract taken for further cleaning

m 49.8003 49.8003 g Sample amount taken for extraction

5. Evaluate the standard uncertainty of each input quantity2

Standard uncertaintyUnit Remark

Imazalil Thiabendazole

uref

0.0375 0.3216 mg kg-1 systematic uncertainty component evaluated based

on the results of ILC

udev

0.0375 0.2367 mg kg-1

random component of uncertainty, calculated using

relative uncertainty (repeatability) of recovery and

method

urel_rec

27 2 %relative standard deviation of recoveries calculated

using addition experiments

urel_meth

10 6 %relative standard deviation of measuring method

(repeated analysis of the same solution)


ww V V

V m=

× × ××

c e10

50

ρ

w e e ew e e e eV e e e e Lρ e e LVe e e e e e LV e e e e e e e Lm e e e e e e

T e e e e e e e e e e e

153


w( ). .

..imazalil mg kg-1=

× × ××

=2 801 10 0 791 150

50 49 80031 335

w( ). .

..thiabendazole mg kg-=

× × ××

=7 398 10 0 791 150

50 49 80033 523 11

7. Calculate the combined standard uncertainty (uw

) of the result and specify units

Using: M e e ee C e e

Uncertainty

componentsValue

Standard


usys

(imazalil) - 0.0530 mg kg-1 systematic uncertainty component

evaluated based on the results of ILC

urnd

(imazalil) - 0.3844 mg kg-1

random component of uncertainty,

calculated using relative uncertainty

(repeatability) of recovery and method

usys

(thiabendazole) - 0.3993 mg kg-1 systematic uncertainty component

evaluated based on the results of ILC

urnd

(thiabendazole) - 0.2228 mg kg-1

random component of uncertainty,

calculated using relative uncertainty

(repeatability) of recovery and method

e e e e ee e

u u u

uu u

w

d w w

u

w sys rnd

rnd

rel_rec rel_meth

ref

ref

= +

=+

×

= −

2 2

2 2

100 %

==

=

= +

s

n

ud

n

u u u

1

dev

sys ref dev

2

2 2

u ee e

u e e e

u e eu e e e e e e eu e e e e e ew e e ed e e e e ee

e e e e ew e e e e e e e

es e e e e e e e

n e e eILC

n e e e ILC

154


u e e e e e ee e e e e e ee

u e e e e e e e e

8. Calculate expanded uncertainty (Uw

) and specify the coverage factor k and the units

Imazalil

u

u

w-1 mg kg

= + =

=+

×

0 05303 0 3844 0 388

27 10

1001

2 2

2 2

. . .

% %

%.rnd 33350 0 3844

1 3350 1 2975 0 0375

0

=

= − =

=

.

. . .

mg kg

mg kg

-1

-1d

uref

...

..

0530

20 0375

0 0375

10 0375

0

2

=

= =

=

mg kg

mg kg

-1

-1u

u

dev

sys .. . .0375 0 0375 0 053032 2+ = mg kg-1

Thiabendazole

u

u

w

rnd

= + =

=+

× =

0 3993 0 2228 0 457

2 6

1003 860 0

2 2

2 2

. . .

% %

%. .

mg kg

-1

22228

3 5230 3 2863 0 2367

0 5571

20 32

mg kg

mg kg

-1

-1d

u

= − =

= =

. . .

..ref 116

0 2367

10 2367

0 3216 0 2367

2

2 2

mg kg

mg kg

-1

-1u

u

dev

sys

= =

= + =

..

. . 00 3993. mg kg-1

U ¥ u ¥ k

U e e ¥ u e e ¥ k

155


9. Analyse the uncertainty contribution and specify the main three input quantities contributing the most to u

w

1 urnd

contribution: 98.13 % (imazalil), 23.74 % (thiabendazole)

2 usys

contribution: 1.87 % (imazalil), 76.27 % (thiabendazole)


T e e e e e ee e I M T e e e ee e e e e e e ee e e e e e

I e e e e e e e e ee e e e e e e e e e

e e e e e ee e e e e T

e e e e e e T e e e e e ee e e e e

e e e e e e e e e e ee e e e e e e e e e e e ILC e e

e e e e e e e e e ee ee e e e e e

ILC e e e e e e e ee e e e e e e e e e

e e e e e e e e e e e ee e

156


Further readings

C Me e e ee e e

e C Q e e e e e ee e e e e e

C Me e e e ee e ee e

M T M e Handbook for Calculation of Measurement Uncertainty in Environmental Laboratories e I

e e e e e e e

157

Chapter 5


Bertil Magnusson

The summary form (‘blue page’) A short introduction to the analytical procedure (‘slides’) All input needed to do the three exercises (‘yellow pages’) The solved exercises (‘green pages’)

158


The TrainMiC example summary form


Measurand Mass concentration of ammonium in drinking water in mg L-1


Author(s) of the example Bertil Magnusson

Analytical procedureDetermination of concentration of ammonium in drinking water by

continuous flow analysis (CFA) and spectrometric detection (ISO 11732:

2005)

Customer requirementDirective 98/83/EC on the quality of water intended for human

consumption

159


II. Attached files

File number, type


File is

attached Remark

Yes No

1 -

I

Ex-07-1-I-

NH4-water-

Photometry-

2006-Ver1.ppt

About the analytical procedure: short

introduction

Given by the

lecturer

2 -

Yel

low Ex-07-2-Y-

NH4-water-

Photometry-

2006-Ver1.doc

PART IDescription of the analytical

procedure

Each participant

receives own

copy and may

keep it

PART II



measurement result

PART III



measurement data

PART IV

Measurement uncertainty of the

result – relevant equations and

measurement data

3 -

Gre

en Ex-07-3-G-

NH4-water-

Photometry-

2006-Ver1.doc


chemistry



PART III


Addendum 1: By spreadsheet

approach




0 April 2007 -

1

Determination of Ammonium in Water by Continuous Flow Analysis (CFA) and

Spectrometric Detection

160




161


162



163


164




Determination of concentration of ammonium in drinking water

by flow analysis (CFA and FIA) and spectrometric detection.


in the Directive 98/83/EC on the quality intended for human

consumption

PART I ................................................................................................................................ 165


PART II .............................................................................................................................. 168

The customer’s requirement concerning quality of the measurement result

PART III ............................................................................................................................. 169


PART IV ................................................................................................................. 171


165


1. Scope

T I e e e e e e e ee e e e e ee L e e e e e I

C e C C e e e e C e e e

2. Principle CFA – Continuous Flow Analysis

I e e e e e e e ee e e e e ee e e

e

T e e e e e e ee e e − C e ee e e ee e e e −

3. Interferences – CFA method

L e e e e e e e e ee e e e I e e e ee e e e e e e e

e e e


166


4. Reagents – here only calibrant is described

Ammonium stock solution, CN

= 1000 mg L-1

e L e ee C C e L e

e e e e e

Standard solutions, 10 mg L-1

P e e L e L ee L e e e

e e e

Calibration solutions

P e e e ee e e e e e e e e

e e ee e e − L

Working solutions 0.1−1.0 mg L-1

P e e e e L e L e e e eL e e e

P e e e e e e

e e ee e ee I

5. Sampling and pre-treatment

e e e I I IC e P PP PT e e e e C e e

C M M e e e e e e e ee e e e e

− C e

167


6. Procedure

Instrument set-up

P e e e e e e ee e e e e e T e e e e e e e

e e e e e

Pe e e ee e e I e e e e e

e e e e C e e e e ee e e ee e e e

e e e e e e e e

e e e e e e e ee

7. Method of calculation

Re e e e e e e e e e e ee e e e e e

C e e e e e e ee e e e e e e e

C e e e Re e e e e eL

168


Extract from the Directive 98/83/EC (Draft annex 2005/04/20), on the quality of water intended for human consumption

T e e e e LT e e e e e e e e

Parameter Trueness of parametric value

(Note 1)

Precision of

parametric value

(Note 2)

Limit of detection of

parametric value

(Note 3)

Ammonium 10 % 10 % 10 %

Note 1 T e e e e e e e e e e ee e ee e e e e e e e e e e e e

Note 2 P e e e e e e ee e ee e e e ee e e e e e e e e

T e e e e e e e I

Note 3: L e e e eee e e e e ee e e e ee e e e e ee

PART II. The customer’s requirement concerning quality of the

measurement result

169


Limit of Detection

Equation

C e e e e ee e e C

Measurement data

e e e e L ee e eT e e L e e e e e

Internal quality control

T e e e e e e e e e ee

Measurement data

Re e e e e e e

Unit QC1 QC2

Mean value mg L-1 0.114 0.605

s mg L-1 0.005 0.021

n - 27 28

Time period months 7 7

Nominal value mg L-1 0.100 0.600



170


External quality control – participating in PT studies

Year/Exercise

Nominal value

xref

[Mg l-1]

laboratory result xi

[mg L-1]

Bias

[%]

sR

[%]

Number of

labs

1999/1 81 83 2.4 10 31

1999/2 73 75 2.7 7 36

2000/1 264 269 1.9 8 32

2000/2 210 213 1.4 10 35

2001/1 110 112 1.8 7 36

2001/2 140 144 2.9 11 34

171


The relevant equations

C = A e – b / b ¥ f / R



172


Mea

sure

men

t d

ata

Qu

anti

tyU

nit

Val

ue

Stan

dar

d

un

cert

ain

ty

Rel

ativ

e st

and

ard

un

cert

ain

ty

Typ

e o

f

un

cert

ain

tyTy

pe

of

dis

trib

uti

on

(u)

(%)

no

rmal

rect

ang

ula

rtr

ian

gu

lar

C

Co

nce

ntr

atio

n o

f

NH

4+ in

th

e sa

mp

le

solu

tio

n

mg

L-1

0.24

650.

0031

1.3

x

Asa

mp

le

Ab

sorb

ance

of t

he

sam

ple

so

luti

on

AU

0.25

600.

0015

0.58

x

b0

Inte

rcep

t o

f

calib

rati

on

lin

eA

U0.

0143

0.00

2114

x

b1

Slo

pe

of c

alib

rati

on

line

– u

nit

AU

div

ided

by

mg

N L

-1

AU

L

mg

-10.

9902

0.00

700.

71x

f dil

Dilu

tio

n fa

cto

ru

nit

less

10.

000.

00

RR

eco

very

fact

or

of

the

anal

ysis

un

itle

ss0.

9900

0.00

580.

59x

173


TrainMiC Exercises


Determination of concentration of ammonium in drinking

water by continuous flow analysis (CFA) and spectrometric

detection


in the Directive 98/83/EC on the quality of water intended for

human consumption

EXERCISE 1:


EXERCISE 2:





EXERCISE 3:


Addendum I: By spreadsheet solution



174



Analyte Ammonium

Measurand Dissolved ammonium in water sample arriving in the laboratory

Units mg L-1


Measurement

procedureISO 11732:2005 using the continuous flow analysis and photometric detection


Model equation

C A e ¥ f R

C C e e e L

A e e e e

b I e e e

b e e e L

f

R Re e e

T e e e e e e e e e e e− L

T e e L e eL T e e e


1 Recovery factor – contributing 30 % to the expanded uncertainty

2 Absorbance of the sample - here the main source is the drift contributing about 20%

3 Calibration – standard solution – purity of ammonium chloride

4 Calibration – volumetric flasks and pipettes


175



For the analyte

1 Name/ChemicalFormula/Producer: Ammonium chloride, NH4Cl, Merck pa min 99 %

2 Name/ChemicalFormula/Producer:



e.g. mass/balance/calibrated by NMI, U = xx (k = 2), see also data yellow sheet

Absorbance – relative measurement. Not direct part of

the traceability chain

2 Quantity/Equipment/Calibration: Volumetric flasks – Class A quality

3 Quantity/Equipment/Calibration:Volumetric pipettes – calibrated by producer and

regularly checked by the laboratory




model equation?Yes No

Other important parameters are: Within-lab reproducibility, contamination


1 Participating in PT rounds

2

3


176




The measurement procedure Measurement procedure is based on EN/ISO11732

Analyte Ammonium

The measurand Dissolved ammonium in water sample arriving in the laboratory

Unit mg L-1


Matrix Drinking water

Measuring range up to 1 mg L-1 for undiluted samples


Intended use of the results To analyse drinking water according to the EU requirements in the EU directive



their values


LODLOD 0.05 mg L-1: - 3s on a natural sample,

5s on a blank: s is repeatability

LOQ

Repeatability

Within-lab

reproducibility

at 0.5 mg L-1, s = 0.025 mg L-1:

at 0.2 mg L-1, s the demand estimated to be

s = 0.010 mg L-1 or 5 %

Truenessat 0.5 mg L-1 less than 0.05 mg L-1 or less than

10 % relative

Measurement

uncertainty

Other-state


VALIDATION






177











6. Measuring range

Linearity

Upper limit

LOD

LOQ


Repeatability



8. Robustness



178


9. Quality control

Control charts




R square





179



11. Calculation of parameters requested by the customer 3

Parameters requested

to be validatedCalculations

LOD

s = 0.004 mg L-1

LOD = 5s = 0.02 mg L-1

LOQ

Repeatability

Within-lab reproducibiltyAt a level of 0.1 mg L-1 s

Rw is 4.4 % and at a level of

0.6 mg L-1 sRw

is 3.5 %.

Trueness

From PT results the trueneness is estimated to be less than

3 %. The trueness is probably around 2 % - then mean value of

the PT results for levels over 0.08 mg L-1.


The measurement uncertainty at a level of 0.2 mg L-1 is estimated

to be 2.5 %. According to EA guideline this value should be

rounded off to 3 %.3


Comment T e e e ee e e e e e e ee e e ee e e e e e e

180





Value obtained

during validation

The requirement

is fulfilled

Yes/No

LOD 0.05 mg L-1 0.02 mg L-1 Yes

LOQ

Repeatability

Within-lab

reproducibility5 % at a level of 0.2 mg L-1 4 % Yes

Trueness 10 % 2-3 % Yes

Measurement

uncertainty

Other

The analytical procedure is t for the intended use:

Yes No


181




Measurand Dissolved ammonium in water sample arriving in the laboratory

Unit mg L-1



e e e e e e e T ee e e e e e e e e

− C e ee e e e e ee e −

Model equation

C = A e – b b ¥ f / R

C e e e LA e e e e

b e e e

b e e e L

f

R e e e




Method bias

Matrix effect

Other: measurement of sample

Other: Preparation, measurement of calibration solutions and constructing the calibration graph

Other:

182




Asample

0.256 AU

b0

0.01734 AU

b1

986.3 AU L mg-1

fdil

1 unitless

R 0.99 unitless


Input

quantity

Standard


Asample

1.49 ¥ 10-3 AU Takes into account repeatability, drift and rounding

b0

0.00207 AU

b1

0.0070 AU L mg-1

Takes into account reference solution (0.3 % relative

uncertainty, preparation and measurement of calibration

standards and constructing the calibration graph

fdil

0 unitlessDilution of sample – in this case the sample was not

diluted

R 0.0058 unitless A rough estimate of recovery of 99 ± 1 %

6. Calculate the value of the measurand, using the model equation.

C = A e – b / b ¥ f / R

C =−

× × =0 256 0 01734

986 31 0 99 0 247

. .

.. . mg L-1

183




Input

quantityValue

Standard


Asample

0.256 1.49 ¥ 10-3 AU

b0

0.01435 0.00207 AU

From calibration graph – note regression without

weights and a slight curvature. A too high

estimate but here we are interested in higher

concentrations.

b1

0.9902 0.0070 AU L mg-1

fdil

1 0 Unitless Sample was not diluted

R 0.99 0.01 Unitless

C = A e – b b ¥ f / R

T e e e L

8. Calculate expanded uncertainty (Uc) and specify the coverage factor k and the units

U k u= × = × =2 0 0031 0 006. . L

T e e e e e e Le e


c

1 Recovery factor – contributing 20 % to the expanded uncertainty

2Absorbance of the sample - here the main source is the drift contributing about 20 % to the expanded

uncertainty

3Preparation of standard solution 10 mg L-1 ± 0.13 mg L-1 (k = 2) - main components dilution using a

1 mL pipette and purity – contribution about 25 %


184


Further readings

I

C C e e C e e T e e e eOf c. J. Eur. Commun. L

M T M e Handbook for Calculation of Measurement Uncertainty in Environmental Laboratories e I

e e e e e e e

185


Addendum: Measurement uncertainty calculation -

GumWorkbench

T e e e e e e e e ee e e e e e e e e e ee e e T e e e e e ee e e e e e e ee

Model equation:

{ The main equation }C = (Asample - b0) / b1 ¥ fdil / R;

{ Nitrogen- Ammonium ion stock solution - 1000 mg N L-1. Prepared from ammonium chloride.}Cst_0 = mNH4Cl / V1000 ¥ PNH4Cl ¥ fNH4Clconv ¥ 1000;

{ Ammonium standard solution - 10 mg N/L. Prepared from ammonium stock solution. The standard solution is further used for preparation of the calibration standard solutions. }Cst = Cst_0 ¥ V1 / V100;

{ Concentrations of calibration standard solutions 0.1 to 1 mg N L-1. 1 to 10 mL of the standard solution is transferred to 100 mL volumetric asks.The reagents are added and the solution is made up to the mark. The solution is left to stand for 60 min and then the absorbance at 655 nm is measured. }C1 = Cst ¥ (V1_st / V1_100);C2 = Cst ¥ (V2_st / V2_100);C3 = Cst ¥ (V3_st / V3_100);C4 = Cst ¥ (V4_st / V4_100);C5 = Cst ¥ (V5_st / V5_100);fdil = 1;{in this case the sample was not diluted}{ Photometric measurementsIt is assumed that the uncertainty of all photometric measurements consists of three components (on the example Asample): – Repeatability uncertainty (included in Asample_rep); – Uncertainty due to drift (Asample_drift) – Uncertainty due to rounding of the reading (Asample_round) (The photometer use din this example has three decimal places)The absorbance of blank is not subtracted but all the measurements are made against blank}{ Absorbance of sample solution }Asample = Asample_rep+Asample_drift+Asample_round;

186


{ The regression equations for nding the slope (b1) and intercept (b0) of the calibration line }ΣAC = C1 ¥ A1 + C2 ¥ A2 + C3 ¥ A3 +C4 ¥ A4 + C5 ¥ A5;AvgC=(C1+C2+C3+C4+C5)/n;AvgA=(A1+A2+A3+A4+A5)/n;ΣCC=C1 ¥ C1+C2 ¥ C2+C3 ¥ C3+C4 ¥ C4+C5 ¥ C5;b1=(ΣAC-n ¥ AvgC ¥ AvgA)/(ΣCC-n ¥ AvgC ¥ AvgC);b0=AvgA-b1 ¥ AvgC

List of quantities:


C mg N L-1 Concentration of NH4

+ in the sample solution

Asample

AU Absorbance of the sample solution

b0

AU Intercept of calibration line

b1

AU L mg-1 Slope of calibration line

fdil

unitless Dilution factor

R unitless Recovery factor of the analysis

Cst_0

mg N mL-1 Concentration of NH4

+ in calibration stock solution

mNH4Cl

g Weight of NH4Cl

V1000

mL Volume of 1 L volumetric flask

PNH4Cl

unitless Purity of NH4Cl

fNH4Clconv

unitlessConversion factor for converting the amount of ammonium chloride (NH

4Cl)

to the amount of nitrogen

Cst

mg N L-1 Concentration of NH4

+ in the ammonium standard solution

V1

mL Volume of 1 mL pipette

V100

mL Volume of 100 mL volumetric flask

C1

mg N L-1 Concentration of the 1st ammonium calibration standard solution

V1_st

mLVolume of ammonium standard solution taken for preparing the 1st

ammonium calibration standard solution

V1_100

mL Volume of the 1st ammonium calibration standard solution

C2

mg N L-1 Concentration of the 2nd ammonium calibration standard solution

V2_st

mLVolume of ammonium standard solution taken for preparing the 2nd


V2_100

mL Volume of the 2nd ammonium calibration standard solution

C3

mg N L-1 Concentration of the 3rd ammonium calibration standard solution

187



V3_st

mLVolume of ammonium standard solution taken for preparing the 3rd


V3_100

mL Volume of the 3rd ammonium calibration standard solution

C4

mg N L-1 Concentration of the 4th ammonium calibration standard solution

V4_st

mLVolume of ammonium standard solution taken for preparing the 4th


V4_100

mL Volume of the 4th ammonium calibration standard solution

C5

mg N L-1 Concentration of the 5th ammonium calibration standard solution

V5_st

mLVolume of ammonium standard solution taken for preparing the 5th


V5_100

mL Volume of the 5th ammonium calibration standard solution

Asample_rep

Asample_drift

Asample_round

ΣAC - Interim quantity for regression statistics calculation

A1

AU Absorbance of the 1th ammonium calibration standard solution

A2

AU Absorbance of the 2nd ammonium calibration standard solution

A3

AU Absorbance of the 3rd ammonium calibration standard solution

A4


A5


AvgC mg N L-1 Interim quantity for regression statistics calculation

n unitless Number of points on the calibration line

AvgA AU Interim quantity for regression statistics calculation

ΣCC - Interim quantity for regression statistics calculation

R:T e e

e ee

mNH4Cl:T e e

e

188


V1000:T e e

e LL

PNH4Cl:T e e

e ee

fNH4Clconv:C

e ¥

V1:T e e

e LL

V100:T e e

e LL

V1_st:T e e

e LL

V1_100:T e e

e LL

V2_st:T e e

e LL

V2_100:T e e

e LL

189


V3_st:T e e

e LL

V3_100:T e e

e LL

V4_st:T e e

e LL

V4_100:T e e

e LL

V5_st:T e e

e LL

V5_100:T e e

e LL

Asample_rep:T e eMe

e ¥e ee ee

Asample_drift:T e eMe

e ¥e ee ee

190


Asample_round:T e e

e

A1:T e e

e

A2:T e e

e

A3:T e e

e

A4:T e e

e

A5:T e e

e

n:C

e e

191


Uncertainty budgets:

C C e e e


uncertaintyDistribution

Sensitivity

coefficient

Uncertainty

contributionIndex

Asample

0.25600 AU 1.48 ¥ 10-3 AU

b0

0.01435 AU 2.07 ¥ 10-3 AU

b1

0.99023

AU L mg-1

7.01 ¥ 10-3

AU L mg-1

fdil

1.0 unitless 0.0 unitless

R 0.99000 unitless5.77 ¥ 10-3

unitlessrectangular -0.25 -1.4 ¥ 10-3 mg L-1 21.3 %

Cst_0

995.01 mg mL-1 2.96 mg mL-1

mNH4Cl

3.81900 g 1.15 ¥ 10-3 g rectangular 0.065 75 ¥ 10-6 mg L-1 0.0 %

V1000

1.000000 mL 577 ¥ 10-6 mL rectangular -0.25 -140 ¥ 10-6 mg L-1 0.2 %

PNH4Cl

0.99500 unitless2.89 ¥ 10-3

unitlessrectangular 0.25 720 ¥ 10-6 mg L-1 5.3 %

fNH4Clconv

0.26185152642501

unitless

Cst

9.9501 mg L-1 0.0649 mg L-1

V1

1.00000 mL 5.77 ¥ 10-3 mL rectangular 0.25 1.4 ¥ 10-3 mg L-1 20.9 %

V100

100.0000 mL 0.0577 mL rectangular -2.5 ¥ 10-3 -140 ¥ 10-6 mg L-1 0.2 %

C1

0.099501 mg L-1 868 ¥ 10-6 mg L-1

V1_st

1.00000 mL 5.77 ¥ 10-3 mL rectangular 0.035 200 ¥ 10-6 mg L-1 0.4 %

V1_100

100.0000 mL 0.0577 mL rectangular -350 ¥ 10-6 -20 ¥ 10-6 mg L-1 0.0 %

C2

0.19900 mg L-1 3.15 ¥ 10-3 mg L-1

V2_st

2.0000 mL 0.0289 mL rectangular 0.031 900 ¥ 10-6 mg L-1 8.4 %

V2_100


C3

0.39800 mg L-1 6.31 ¥ 10-3 mg L-1

V3_st

4.0000 mL 0.0577 mL rectangular 0.023 1.3 ¥ 10-3 mg L-1 17.9 %

V3_100


192



uncertaintyDistribution

Sensitivity

coefficient

Uncertainty

contributionIndex

C4

0.59701 mg L-1 4.00 ¥ 10-3 mg L-1

V4_st

6.00000 mL 8.66 ¥ 10-3 mL rectangular 0.014 120 ¥ 10-6 mg L-1 0.2 %

V4_100


C5

0.99501 mg L-1 6.67 ¥ 10-3 mg L-1

V5_st

10.0000 mL 0.0144 mL rectangular -2.7 ¥ 10-3 -39 ¥ 10-6 mg L-1 0.0 %

V5_100

100.0000 mL 0.0577 mL rectangular 270 ¥ 10-6 16 ¥ 10-6 mg L-1 0.0 %

Asample_rep

0.256000 654 ¥ 10-6 normal 1.0 670 ¥ 10-6 mg L-1 4.6 %

Asample_drift

0.0 1.30 ¥ 10-3 normal 1.0 1.3 ¥ 10-3 mg L-1 18.2 %

Asample_round

0.0 289 ¥ 10-6 rectangular 1.0 290 ¥ 10-6 mg L-1 0.9 %

ΣAC 1.5720 - 0.0108 -

A1

0.108000 AU 577 ¥ 10-6 AU rectangular -0.36 -210 ¥ 10-6 mg L-1 0.4 %

A2


A3


A4

0.60600 AU 1.15 ¥ 10-3 AU rectangular -0.14 -170 ¥ 10-6 mg L-1 0.3 %

A5

0.99790 AU 1.15 ¥ 10-3 AU rectangular 0.027 31 ¥ 10-6 mg L-1 0.0 %

AvgC 0.45771 mg L-1 3.27 ¥ 10-3 mg L-1

n 5.0 unitless

AvgA 0.467580 AU 404 ¥ 10-6 AU

ΣCC 1.5544 - 0.0211 -

C 0.24650 mg L-1 3.11 ¥ 10-3 mg L-1

Results:

Quantity ValueExpanded

uncertaintyCoverage factor Coverage

C 0.2465 mg L-1 2.5 % (relative) 2.00 manual

193

Appendix 1

TrainMiC® Exercises (‘white pages’)

TrainMiC Exercises (‘white pages’)

195

TrainMiC Exercises

Analytical procedure:

EXERCISE 1:


EXERCISE 2:





EXERCISE 3:




196


e e T MPL T e T MeP e e T M C

e M e P TI e M

e e T M C e


197



Analyte

Measurand

Units


Measurement

procedure

Type of calibration standard curve Standard addition internal standard

Model equation

198


3. List the input quantities according to their influence on the uncertainty of the result of the measurement (first the most important ones). At this point, your judgement should be based on your previous experience only

1

2

3

4

5


For the analyte






(k = 2) see also data yellow sheet





Are all important parameters included in the model

equation?Yes No



1

2

3


199


200




The measurement procedure

Analyte

The measurand

Unit


Matrix

Measuring range


Intended use of the results:



their values


LOD

LOQ

Repeatability


Trueness


Other-state


VALIDATION







201











6. Measuring range

Linearity

Upper limit

LOD

LOQ


Repeatability



8. Robustness


202


9. Quality control

Control charts

Participation in proficiency testing schemes



R squared






203





LOD

LOQ

Repeatability


Trueness






Value obtained

during validation

The requirement

is fulfilled

Yes/No

LOD

LOQ

Repeatability

Within-lab

reproducibility

Trueness

Measurement

Other


Yes No


204



EXERCISE


Measurand

Unit



Model equation:




Method bias

Matrix effect

Other:

Other:

Other:


205









Input

quantityValue

Standard



units

206



c

1

2

3



207

Addendum I: Measurement uncertainty calculation:


Addendum II: Measurement uncertainty calculation –

GumWorkbench

209

Appendix 2


210



211

212



213

214



215

Notes

216


Notes

European Commission – Joint Research Centre – Institute for Reference Materials and Measurements

EUR 22791/2 EN – Practical examples on traceability, measurement uncertainty and validation in chemistry Vol. 1

e M e P T

L e P e e e

R e Te Re e e e IISBN 978-92-79-12021-3

RC

Abstract

C e e e e e e e e e ee e e e

e e e e e e e e ee T M C® e e e e e T M C® e e e ee e e e e e e e e e T M C® e e

HOW TO OBTAIN EU PUBLICATIONSFree publications:

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practical examples on traceablity, measurement uncertainty and validation in chemistry; vol 1 by...

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