Practical Gas Chromatographic Analyses Using ICP-MS Detection

Transcription

1 Practical Gas Chromatographic Analyses Using ICP-MS Detection William M. Geiger Consolidated Sciences

2 Why GC-ICP-MS 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 ppb Germane MDQ ~ 1 ppb GC/MS MDQ ~ 5 ppb GC-AED MDQ ~ 5 ppb

3 Why GC-ICP-MS GC-ICP-MS Effort in ppb Germane MDQ ~ 2-4 ppt Column: 100 m X 0.53 mm X 5.0 um DB-1 Detector Agilent 8800 QQQ using ORS with O 2, m/z 74 -> m/z 90

4 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, H 2, N 2, O 2, F Very Expensive Detector Uses a Lot of Argon Very Expensive

5 Petroleum and Petrochemical Applications

6 Count Sulfur in n-gas Column: 100 m X 0.53 mm X 5.0 um DB-1 Carrier: 12 psig Initial Temperature: 30 deg C Initial Time: 5.4 minutes Ramp: 15 deg C/ minute Final Temperature: 220 deg C Full Time Range EIC(32) : 018SMPL.d x SMPL.d 017SMPL.d 4 Methyl Mercaptan + n-butane 2 0 Ethyl Mercaptan + Dimethyl sulfide + n-pentane RT(min)

7 Sulfur in Naphtha Abundance TIC: NAPHTHA_ _ _PM_-RUN-_1-.D H 2 S Thiophene Methyl Thiophenes Dimethyl Thiophenes Time-->

8 Sulfur in Jet Fuel Abundance TIC: 32JET_ _ _AM_-RUN-_1-.D Methyl Thiophenes Dimethyl Thiophenes Benzothiophenes Time-->

9 Thiophene in Benzene Abundance Time--> Ion (47.70 to 48.70): WAX_100_PPBIN_BENZENE_3 100 ppb Thiophene Column: Carbowax 20M

10 Aviation Gasoline 100 LL Analysis 13 C chromatogram 35 Cl chromatogram (ISTD) 204 Pb chromatogram

11 Siloxanes Compound MW BP C (F) vp mmhg Hexamethylcyclotrisiloxane 222 D (275) 10 Octamethylcyclotetrasiloxane 296 D 4 175, (348) 1.3 Decamethylcyclopentasiloxane 370 D 5 211, (412) 0.4 Dodecamethylcyclohexasiloxane 444 D 6 245, (473) 0.02 Hexamethyldisiloxane 162 L 2, MM 106, (224) 31 Octamethyltrisiloxane 236 L 3, MDM? 3.9 Decamethyltetrasiloxane 310 L 4, MD 2 M? 0.55 Dodecamethylpentasiloxane 384 L 5, MD 3 M? 0.07

12 Siloxanes in Gasoline, ~ 5 ppm L 2 L 3 L 4 Column: 60 meter x 0.32 mm x 1.8 um VOCOL (Supelco) Carrier: constant flow 2 mls/minute, Split 15:1 Initial Temperature: 40 o C for 5 minutes Ramp 1: 5 o C /minute to 70 o C Hold: 0 minutes Ramp 2: 10 o C /minute to 230 o C Hold: 20 minutes Top Chromatogram: ICP-MS, conventional hard extract (m/z 28) Bottom Chromatogram: ICP-MS, hard extract (m/z 13)

13 Siloxanes in Gasoline, ~ 5 ppm L 4 L 3 L 2 L 2 L 3 L 4 Column: 60 meter x 0.32 mm x 1.8 um VOCOL (Supelco) Carrier: constant flow 2 mls/minute, Split 15:1 Initial Temperature: 40 o C for 5 minutes Ramp 1: 5 o C /minute to 70 o C Hold: 0 minutes Ramp 2: 10 o C /minute to 230 o C Hold: 20 minutes Top Chromatogram: ICP-MS, hard extract (m/z 28), 3.5 mls/min H 2 to ORS Bottom Chromatogram: ICP-MS, conventional hard extract (m/z 28), No H 2 to ORS

14 Siloxanes in Coker Naphtha Si, 28 > 28 ion chromatogram D 3, 3 ppm D 4, 2.7 ppm D 5, 1.7 ppm D 6, 0.93 ppm C, 13 > 13 ion chromatogram Column: 30 meter x 0.32 mm x 0.25 um HP-5 Carrier: 2.5 mls/min Initial Temp.: 50 o C Hold: 2 minutes Ramp: 15 o C/minute Final Temp.: 270 o C 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.

15 Siloxanes in Town Gas D5 TMS D3 D4 L3 Compound ppmv as Si D L D D TMS 0.32

16 Propylene Propylene contaminants include phosphine (PH 3 ), Arsine (AsH 3 ), Hydrogen Sulfide (H 2 S), 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: 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 m/z 32 -> m/z 48 m/z 74 -> m/z 90 m/z 75 -> m/z seconds/mass 0.4 seconds/mass 0.1 seconds/mass 0.1 seconds/mass

17 Propylene Contaminants, Arsine AsH 3, 11.4 ppb DL ~30 ppt

18 Propylene Contaminants, PH 3 PH 3, 1.7 ppb spike Methane, 1.77 % Ethane, 1.04 % PH 3 DL ~ 0.15 ppb. This chromatogram illustrates positive interference for P.

19 Propylene Contaminants, H 2 S and COS H 2 S Spike COS Spike H 2 S Standard COS Standard Propylene 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 H 2 S and COS ~ 3 ppb

20 10 port GSV for Standard Addition Load Carrier Column Inject Carrier Column Std Loop Std Loop Sx Loop Sx Loop

21 Health and Environmental

22 Single column analysis of PBDE mix containing 14 common congeners from tri to deca 50 pg on column, 250 pg Deca minutes Courtesy of Steve Wilbur and Emmett Soffey

23 Tin Species in Landfill Gas Courtesy of Eva Krupp 2008 Plasma Winter Conference , , 7a Me 4 Sn; 2 Me 3 SnEt; 3 Me 3 Sni-Pr; 4 Me 3 SnPr; 5 Me 2 SnEt 2 ; 6 Me 2 SnEtiPr; 7 Me 3 SnBu; 7a Me 2 SnEtPr; 8 MeSnEt 3 ; 9 Me 2 SnPr 2 ; 10 Et 4 Sn; 11 Et 3 SnPr; 12 Et 2 SnPr 2 ; 13 BuSnEt3; 14 EtSnPr 3 ; 15 Bu 2 SnEt2; 16 Bu 2 SnPr 2

24 Specialty And General Applications

25 GC-ICP-MS Analysis of CF 3 I Matrix Vent Region 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

26 Count Fluorobutene Impurities Full Time Range EIC(13) : 104SMPL.d x Ethene, % 2 COS, 27 ppm 3 Difluorodimethylsilane, 80 ppm 4 Butene, 0.21 % Butene, 1.30 % 6 Butene, 1.29 % 7 2-Fluorobutene, matrix 8 Methylene Chloride, 0.23 % 9 Carbon Disulfide, 9 ppm RT(min)

27 Electronic and Semi-Conductor

28 Single Tune Detection for Phosphine Impurities Detector: Agilent 7700 ICP-MS, Column: 200 m x 0.53 x 5.0 µm 30 o C Germane, GeH 4, m/z 74 Arsine, AsH 3, m/z ppb, DL 5 ppt 33 ppb, DL 100 ppt Silane, SiH 4, m/z 28 Arsine, AsH 3, m/z ppb, DL 3 ppb 234 ppt

29 Single Tune Detection for Phosphine Impurities Detector: Agilent 7700 ICP-MS, Column: 30 m x 0.53 mm x 20 µm df 50 C, Sample size: 75 µl H 2 S: 32 ppb standard COS: 32 ppb standard H 2 S: 13 ppb DL: 3 ppb based on 3 sigma

30 Count Full Time Range EIC(31) : d x ppm Diphosphine 24 ppm Diphosphine Phosphine 'tail' Tail 2 Dean's Switch Phosphine Vent Phosphine Homologs 20 ppb 20 ppb Triphosphine RT(min)

31 Germane (GeH 4 ) Homologs Trigermane, 22 ppb n-tetragermane, 7 ppb iso-tetragermane, 5 ppb neo-tetragermane, 1ppb

32 Isotopic Analysis 11 B = Found 11 B = % Theoretical 11 B = 80.1 % 10 B = B = Enriched 11 B = % 10 B = 458

33 Interfacing

34 Interfacing Agilent 7700, 7900, 8800 To Transfer Line/Torch Dilution Gas Switching Valve Needle Valve Vent Column

35 Interfacing Agilent 7700, 7900, 8800 Simultaneous GC and Wet Plasma Dilution Gas/GC Effluent Standard or Blank Make-up Gas Carrier/Nebulizer Gas

36 Interfacing Simultaneous GC and Wet Plasma Agilent 7700, 7900, 8800 Dilution Gas/GC Effluent Spray Chamber End View To Torch Make-up Gas Carrier/Nebulizer Gas Standard or Blank

37 Cross Calibration Using CIC

38 Ni Fe Mo Carbon Monoxide Ni Co Fe

39 Carbon Monoxide Theory % Found % 50 Cr Cr Cr Cr Cr 58 Ni 54 Fe

40 Ni signal = 99,440 (0.17 umoles/l) Counts/umole= 228,328 Br signal = 99,440 (12.8 umoles/l) Counts/umole= 7801 X RRF Ni = 7801/228,328 =

41 101 ppb Methyl Bromide Unknown Ni(CO) 4 DL ~ 80 ppt Nickel Carbonyl = x x 101 ppb / = 3.1 ppb

42 The obvious advantage to analyzing Fe in the H 2 mode is illustrated by these two chromatograms. This is a sample of CO containing 0.72 ppb iron carbonyl. Fe, He mode DL ~ 140 ppt Nickel works better in the He mode. Fe, H 2 mode DL ~ 46 ppt

43 Carbon Monoxide Fe, H 2 mode CO matrix Ni, He mode mode switch 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.

44 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

45 Acknowledgments Emmett Soffey - Agilent Steve Wilbur- Agilent Jesus Anguiano CONSCI, LTD Blake McElmurry CONSCI, LTD