Practical Gas Chromatographic Analyses Using

ICP-MS Detection

William M. Geiger Consolidated Sciences

www.conscicorp.com

bill@conscicorp.com

Why GC-ICP-MS

7.4ppb Germane

MDQ ~ 1 ppb

GC/MS MDQ ~ 5 ppb

GC-AED MDQ ~ 5 ppb

Chapter 3 “ (ICP-MS) is too costly to use as a GC detector except for the most demanding applications.” W.M. Geiger

GC-ICP-MS Effort in 1995

4.1 ppb Germane

MDQ ~ 2 - 4 ppt

GC-ICP-MS Effort in 2014

Why GC-ICP-MS

Column: 100 m X 0.53 mm X 5.0 um DB-1

Detector Agilent 8800 QQQ using ORS with O2, m/z 74 -> m/z 90

Why GC-ICP-MS

Advantages

• Universal and Specific

• Extremely Sensitive

• Robust Plasma

• Single Tune for Most Elements

• Compound Independent Calibration (CIC)

• Isotope Measurement

Disadvantages

• Insensitive to Carbon *

• Cannot measure, H2, N2, O2, F

• Very Expensive Detector

• Uses a Lot of Argon

• Very Expensive

Petroleum and

Petrochemical Applications

Full Time Range EIC(32) : 018SMPL.d

RT(min)

8.0 16.0 24.0

Co

un

t

6x10

0

2

4

018SMPL.d

017SMPL.d

Methyl Mercaptan + n-Butane

Ethyl Mercaptan + Dimethyl sulfide + n-Pentane

Column: 100 m X 0.53 mm X 5.0 um DB-1 Carrier: Helium @ 12 psig Initial Temperature: 30 deg C Initial Time: 5.4 minutes Ramp: 15 deg C/ minute Final Temperature: 220 deg C

Sulfur in n-Gas

Sulfur in Naphtha

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00

500000

1000000

1500000

2000000

2500000

3000000

3500000

4000000

4500000

5000000

5500000

Time-->

Abundance

TIC: NAPHTHA_7-23-2005_8-48-29_PM_-RUN-_1-.D

Methyl

Thiophenes

Dimethyl

Thiophenes

Thiophene

H2S

Sulfur in Jet Fuel

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00

500000

1000000

1500000

2000000

2500000

3000000

3500000

4000000

4500000

5000000

5500000

6000000

6500000

Time-->

Abundance

TIC: 32JET_7-24-2005_12-23-44_AM_-RUN-_1-.D

Methyl Thiophenes

Dimethyl Thiophenes Benzothiophenes

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00

14500

15000

15500

16000

16500

17000

17500

18000

18500

19000

19500

20000

20500

21000

21500

22000

22500

23000

23500

Time-->

Abundance

Ion 48.00 (47.70 to 48.70): WAX_100_PPBIN_BENZENE_3

100 ppb Thiophene

Column: Carbowax 20M

Thiophene in Benzene

35Cl chromatogram (ISTD)

13C chromatogram

204Pb chromatogram

Aviation Gasoline 100 LL Analysis

Compound MW BP C (F) vp mmHg

Hexamethylcyclotrisiloxane 222 D3 135 (275) 10

Octamethylcyclotetrasiloxane 296 D4 175, (348) 1.3

Decamethylcyclopentasiloxane 370 D5 211, (412) 0.4

Dodecamethylcyclohexasiloxane 444 D6 245, (473) 0.02

Hexamethyldisiloxane 162 L2, MM 106, (224) 31

Octamethyltrisiloxane 236 L3, MDM ? 3.9

Decamethyltetrasiloxane 310 L4, MD

2M ? 0.55

Dodecamethylpentasiloxane 384 L5, MD

3M ? 0.07

Siloxanes

L2

Siloxanes in Gasoline, ~ 5 ppm

L3

L4

Column: 60 meter x 0.32 mm x 1.8 um VOCOL (Supelco) Carrier: He @ constant flow 2 mls/minute, Split 15:1 Initial Temperature: 40 oC for 5 minutes Ramp 1: 5 oC /minute to 70 oC Hold: 0 minutes Ramp 2: 10 oC /minute to 230 oC Hold: 20 minutes Top Chromatogram: ICP-MS, conventional hard extract (m/z 28) Bottom Chromatogram: ICP-MS, hard extract (m/z 13)

L2

L3

L4

Siloxanes in Gasoline, ~ 5 ppm

Column: 60 meter x 0.32 mm x 1.8 um VOCOL (Supelco) Carrier: He @ constant flow 2 mls/minute, Split 15:1 Initial Temperature: 40 oC for 5 minutes Ramp 1: 5 oC /minute to 70 oC Hold: 0 minutes Ramp 2: 10 oC /minute to 230 oC Hold: 20 minutes Top Chromatogram: ICP-MS, hard extract (m/z 28), 3.5 mls/min H2 to ORS Bottom Chromatogram: ICP-MS, conventional hard extract (m/z 28), No H2 to ORS

L2

L3

L4

D3, 3 ppm D4, 2.7 ppm

D5, 1.7 ppm

D6, 0.93 ppm

Column: 30 meter x 0.32 mm x 0.25 um HP-5

Carrier: Helium @ 2.5 mls/min

Initial Temp.: 50 oC

Hold: 2 minutes

Ramp: 15 oC/minute

Final Temp.: 270 oC

ICP-MS 8800 QQQ was used for detection. Spectrometer was run in MS/MS mode using hydrogen in the octapole reaction system (ORS) in order to minimize hydrocarbon interference.

Siloxanes in Coker Naphtha

Si, 28 > 28 ion chromatogram

C, 13 > 13 ion chromatogram

Compound ppmv as Si

D3 2.24

L3 0.08

D4 2.08

D5 5.56

TMS 0.32

Siloxanes in Town Gas

D3 D4

D5

L3

TMS

Propylene Propylene contaminants include phosphine (PH3), Arsine (AsH3), Hydrogen Sulfide (H2S), and Carbonyl Sulfide (COS). A desirable method for analyzing these contaminants would be use of a single column and a single detector. Megabore (0.53mm) boiling point have been useful for this analysis, but suffer from the fact that COS elutes with the propane/propylene matrix. The Agilent PLOT U column also works well, but presence of ethane can give a false peak. It has been found that the Agilent Select Low Sulfur column satisfies all separation problems.

Carrier: Helium @ 20 psig Column: Select Low Sulfur 60 m x 0.32 mm

Temperature: 35 degrees isothermal Sample Size: 400 ul

Split: ~ 4:1 Detection: 8800 QQQ MS MS

Acquisition: m/z 31 -> m/z 47 0.4 seconds/mass m/z 32 -> m/z 48 0.4 seconds/mass m/z 74 -> m/z 90 0.1 seconds/mass m/z 75 -> m/z 91 0.1 seconds/mass

AsH3, 11.4 ppb

Propylene Contaminants, Arsine

DL ~30 ppt

PH3, 1.7 ppb spike

Ethane, 1.04 % Methane, 1.77 %

PH3 DL ~ 0.15 ppb. This chromatogram illustrates positive interference for P.

Propylene Contaminants, PH3

H2S Standard COS Standard

H2S Spike

COS Spike

The matrix effect is more pronounced as the analyte is closer to the matrix. This chromatogram also illustrates the negative interference hydrocarbons have on the sulfur response. DL for H2S and COS ~ 3 ppb

Propylene

Propylene Contaminants, H2S and COS

Carrier

Column

Sx Loop

Std

Loop

Std

Loop

Carrier

Column

Sx Loop

LoadInject

10 port GSV for Standard Addition

Health and

Environmental

Single column analysis of PBDE mix containing 14 common congeners from tri to deca 50 pg on column, 250 pg Deca- 10.5 minutes

Courtesy of Steve Wilbur and Emmett Soffey

Tin Species in Landfill Gas Courtesy of Eva Krupp 2008 Plasma Winter

Conference

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

150 200 250 300 350 400 450

1

6 5 4 3

2

12, 13

7, 7a

8

14 11 10

9

16

1 Me4Sn; 2 Me3SnEt; 3 Me3Sni-Pr; 4 Me3SnPr; 5 Me2SnEt2; 6 Me2SnEtiPr; 7 Me3SnBu; 7a Me2SnEtPr; 8 MeSnEt3; 9 Me2SnPr2; 10 Et4Sn; 11 Et3SnPr; 12 Et2SnPr2; 13 BuSnEt3; 14 EtSnPr3; 15 Bu2SnEt2; 16 Bu2SnPr2

Specialty And

General Applications

GC-ICP-MS Analysis of CF3I

1 Trace Sulfur compound

2 Octafluoropropane

3 Trifluoromethane

4 Carbon Dioxide

5 Pentafluoroethane

6 Hexafluoropropene

7 Octafluorobutene + Octafluorocyclobutane

8 Octafluorobutene +

9 Br compound 10 Pentafluoropropene +

11 Sulfur compound

12 Hexafluoropropane

13 Chlorodifluoromethane +

14 Br compound

15 Sulfur compound

16 Cl compound trace

17 Br compound trace

18 Methyl Bromide ?

19 Br compound trace

20 Sulfur compound trace

21 Cl compound trace

22 Br compound trace

Matrix Vent Region

Full Time Range EIC(13) : 104SMPL.d

RT(min)

7.0 14.0 21.0

Co

un

t

7x10

-1

-0.5

0

0.5

1

2

3

4

5

6

7

8

9

13

28

32

35

1 Ethene, 15.68 % 2 COS, 27 ppm 3 Difluorodimethylsilane, 80 ppm 4 Butene, 0.21 % 5 Butene, 1.30 % 6 Butene, 1.29 % 7 2-Fluorobutene, matrix 8 Methylene Chloride, 0.23 % 9 Carbon Disulfide, 9 ppm

Fluorobutene Impurities

1

2

3

4

5 6

7

8

9

Electronic and

Semi-Conductor

Single Tune Detection for Phosphine Impurities Detector: Agilent 7700 ICP-MS, Column: 200 m x 0.53 x 5.0 µm DB-1 @ 30oC

Germane, GeH4, m/z 74 Arsine, AsH3, m/z 75

Silane, SiH4, m/z 28 Arsine, AsH3, m/z 75

33 ppb, DL ∼ 3 ppb

33 ppb, DL ∼ 100 ppt

234 ppt

33 ppb, DL ∼ 5 ppt

H2S: 13 ppb

COS: 32 ppb standard H2S: 32 ppb standard

DL: ∼3 ppb based on 3 sigma

Single Tune Detection for Phosphine Impurities Detector: Agilent 7700 ICP-MS, Column: 30 m x 0.53 mm x 20 µm

df HP-PLOT/U @ 50°C, Sample size: 75 µl

Full Time Range EIC(31) : 14357-003.d

RT(min)

4.0 8.0 12.0

Co

un

t

5x10

0

1

2

3

20 ppb Triphosphine

24 ppm Diphosphine

Phosphine 'tail'

Dean's Switch

Phosphine Homologs

24 ppm Diphosphine

20 ppb Triphosphine

Phosphine Tail

Phosphine Vent

n-Tetragermane, 7 ppb

Trigermane, 22 ppb

iso-Tetragermane, 5 ppb neo-Tetragermane, 1ppb

Germane (GeH4) Homologs

11B = 3431999

10B = 458

11B = 14738129

10B = 3495946

Found 11B = 80.82 %

Theoretical 11B = 80.1 %

Enriched 11B = 99.99 %

Isotopic Analysis

Interfacing

Column

Switching Valve

To Transfer Line/Torch

Vent

Needle Valve

Dilution Gas

Interfacing Agilent 7700, 7900, 8800

Carrier/Nebulizer Gas

Make-up Gas Standard or Blank

Dilution Gas/GC Effluent

Simultaneous GC and Wet Plasma Interfacing Agilent 7700, 7900, 8800

Interfacing

To Torch

Make-up Gas

Carrier/Nebulizer Gas

Dilution Gas/GC Effluent

Standard or Blank

Agilent 7700, 7900, 8800

Simultaneous GC and Wet Plasma

Spray Chamber End View

Cross Calibration Using CIC

Mo

Ni

Fe

Ni Co

Fe

Carbon Monoxide

58Ni

54Fe

52Cr

Theory

%

Found

%

50Cr 4.35 3.91

52Cr 83.79 83.09

53Cr 9.50 10.23

54Cr 2.37 2.78

Carbon Monoxide

Ni signal = 99,440

(0.17 umoles/L)

Counts/umole= 228,328

Br signal = 99,440 (12.8 umoles/L)

Counts/umole= 7801

X RRFNi = 7801/228,328 = 0.0342

Nickel Carbonyl = 16711 x 0.0342 x 101 ppb / 18874 = 3.1 ppb

101 ppb Methyl Bromide

Unknown Ni(CO)4

DL ~ 80 ppt

The obvious advantage to analyzing Fe in the H2

mode is illustrated by these two chromatograms. This is a sample of CO containing 0.72 ppb iron carbonyl. Nickel works better in the He mode.

Fe, H2 mode

Fe, He mode

DL ~ 46 ppt

DL ~ 140 ppt

This chromatogram illustrates the switching time going from Helium in the ORS to Hydrogen. The acquisition time was also changed since the iron carbonyl was a broader peak.

Carbon Monoxide

mode switch

Ni, He mode

Fe, H2 mode

CO matrix

Resources

Journal of Analytical Atomic Spectrometry

Handbook of Hyphenated ICP-MS Applications - Agilent

Agilent 8800 ICP-QQQ Application Handbook - Agilent

Practical Guide to ICP-MS – Robert Thomas, CRC Press

ICP Mass Spectrometry Handbook, Simon M. Nelms, CRC Press

Trace Analysis of Specialty and Electronic Gases, Geiger and Raynor, Wiley

Acknowledgments

Emmett Soffey - Agilent

Steve Wilbur- Agilent

Jesus Anguiano – CONSCI, LTD

Blake McElmurry – CONSCI, LTD