Ralf Matschat*, Tamara Gusarova*, Britta Lange*, Heinrich Kipphardt*, Joachim Hinrichs**, Ulrich Panne*

Transkript

1 Rückführbare Messungen zur Multielement-Spurenbestimmung metallischer und nichtmetallischer Analyten in Reinstmetallen mit dem neuen Glimmentladungs-Massenspektrometer Element-GD Ralf Matschat*, Tamara Gusarova*, Britta Lange*, Heinrich Kipphardt*, Joachim Hinrichs**, Ulrich Panne* *BAM Bundesanstalt für Materialforschung und prüfung, Berlin Abteilung I (Prof. U. Panne) **Thermo Fisher Scientific

2 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

3 Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

4 Metrological Pyramid Uncertainty SI unit P CRM BAM certified Matrix CRM (secondary) RM In house -RM

5 Dissemination of primary standards Uncertainty Measurement result in field laboratory e.g. copper in tap water traceable commercial calibration solutions Transfer solution e.g. PT-B001T Primary calibration solution e.g. PTB-001 Primary standard e.g. BAM-Y001 (copper) SI Procedure of the routine laboratory Certification procedure Precision procedure (PTB) Gravimetrical preparation (PTB) Purity determination?,?? % 0,30 % 0,10 % 0,05 % 0,01 % 0 %

6 Reality: Accuracy of different commercial calibration solutions 960 mg/l (according measurements by EMPA) 1000 m g/l* 1040 mg/l Ca Cd Cr Cu Fe Mg Certified interval Determined value (acceptable) Determined value (not acceptable) Mo Ni Pb 960 mg/l 1000 m g/l* 1040 mg/l

7 Materials certified for total purity hardly exist... usually incompletely characterised using semi-quantitative measurement techniques... no uncertainty statement

8 Typical example for this problem: Copper purity BAM-B-primary- BAM-A-primary-Cu-1 nominal metallic (m6n) (m4n) metallic' based (by BAM) total (certified by BAM) ± ± (t3n5) ± ± (t4n7)

9 Target: Primary standards of high metrological quality... small uncertainty according to GUM... serve as National Standards for Elemental Analysis in Germany (with PTB)... can serve as primary back-spikes for IDMS in European JEPPIM-project... can serve as transfer standard in thermometry, co-operation with PTB, NMIJ

10 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

11 Primary standards of Type A intended for analyte calibration (i.e. element amount standard)... certified for the mass fraction of the matrix element in a pure material (e. g. copper mass fraction of a pure copper material)... for use within the NMIs multiplication to the field via cooperation

12 Primary standards of type A... Mass fraction w(e) known better than 0.01%... approach: 100 % - ΣImpurities... measurement of all impurity elements (including non metals...)... measurement of total impuritiy content (bulk and surface after defined etching)

13 A Primary Standard of type A: Trace contents and certification of primary copper (type A) BAM-Y001 Mass fractions above LOQ ; Sum: 9.95 ± 3.61 mg/kg Mass fractions below LOQ ; Sum: ± 3.84 mg/kg Mass fractions estimated Certified mass fraction: ± % (U, k= 2) H He < 2.1 < Li Be B C N O F Ne < 0.31 < 1.1 < < 2 < Na Mg Al Si P S Cl Ar < 0.05 < 0.07 < < < 0.6 < K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr < < 0.06 < 0.32 < < 5 < matrix < 0.11 < < < Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe < 0.05 < < 0.03 < < 0.02 < 0.06 < < 0.03 < 1.6 < < < < 0.22 < 0.09 < Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn < < < < < < 0.12 < < < < < < 0.03 < < < < Fr Ra Ac < < < Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu < < < 0.21 < < < < < < < < < < < Th Pa U < 0.02 < < 0.001

14 Measurements using different methods (BAM Y001) mass fraction in mg/kg ,1 HR ICP MS ET AAS ICP-OES HE/PAA HE/IR Photometrie INAA 0,01 Ag As Bi C Ca Cr Fe N Ni O Pb S Sb Se Si Sn

15 BAM/HKi/01-27 I.1902 April 2004 Certification of the mass fraction of copper in Primary Reference Material BAM-Y001 BAM-Y001 certification report CERTIFICATION REPORT Version of edited by Heinrich Kipphardt Bundesanstalt für Materialforschung und -prüfung Richard-Willstätterstr Berlin Germany Warning: This report has been produced for internal use at BAM. It can only be quoted with permission of the authors and referred to as a private communication.

16 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

17 Certification approach ET and HG AAS validation additional information consistency check HR ICP MS continuous Nebulization (all metallic analytes) LA-ICP MS check of dissolution step ICP OES, (INAA) validation additional information? Gas and non-metal determination CGHE; PAA nuclear methods certified value combined uncertainty (GUM)

18 Certification approach ET and HG AAS validation additional information consistency check HR ICP MS continuous Nebulization (all metallic analytes) LA-ICP MS check of dissolution step ICP OES, (INAA) validation additional information Need of additional information Gas and non-metal determination CGHE; PAA nuclear methods certified value combined uncertainty (GUM)

19 Certification approach ET and HG AAS validation additional information consistency check HR ICP MS continuous Nebulization (all metallic analytes) LA-ICP MS check of dissolution step ICP OES, (INAA) validation additional information Need Fast of overview additional information Losses, Contamination Gas and non-metal determination CGHE; PAA nuclear methods certified value combined uncertainty (GUM)

20 Certification approach ET and HG AAS validation additional information consistency check HR ICP MS continuous Nebulization (all metallic analytes) LA-ICP MS check of dissolution step ICP OES, (INAA) validation additional information GD-MS Glow discharge Mass spectrometry Gas and non-metal determination CGHE; PAA nuclear methods certified value combined uncertainty (GUM)

21 Task of GD MS in context of PCRM Liquid sampling methods (such as HR ICP-MS): time consuming have analyte losses or contamination in some cases need to be supported by faster independent direct solid sampling methods Glow discharge mass spectrometry (GD-MS): solid sampling method with very low limits of quantification (LOQ). The question is: how to use the new generation of fast GD-MS (Thermo ELEMENT GD) for this purpose? how can it be calibrated for achieving reliable results which are traceable to SI?

22 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

23 Magnet ESA Main advantages of Finnigan ELEMENT GD (Thermo Fisher Scientific) Ion Transfer Optics Faraday SEM Cup Detection System GD Ion Source (with Sample Holder) Grimm-type ion source High sputter rate, short analysis time High sample throughput (6 Samples per hour) More than 12 orders of magnitude automatic detection system Complete determination of matrix and trace elements (up to ng/kg) Extremely high SBR (Signal to Background Ratio) Double focussing mass spectrometer (Resolution up to 10000)

24 Principle Constructional Diagram of the Grimm Type Glow Discharge

25 Opened sample chamber of Finnigan GD Element cathode plate sample chamber anode tube water cooling sample holder

26 Placement of sample and sample holder closed sample chamber placement of the sample holder into the GD source sample holder with sample

27 Problems of GD-MS GD-MS as solid sampling method needs calibration by solid samples similar to the samples to be analyzed. For most tasks of PCRMs adequate matrix CRMs do not exist external calibrations often cannot be carried out. Additionally, even if calibration materials would exist, those measurements would not be directly traceable to SI unit. In GD-MS mainly analyses are carried out based on: Element and matrix specific relative sensitive factors (RSFs, inaccuracy: ~ factor 2or higher), not directly traceable to SI unit Standard RSF values (SRSF), for semi-quanzitative analysis Both groups of values do not completely exist for the new GD-MS spectrometer Element GD with its new GD cell of Grimm type in opposite to the many RSF and SRSF values collected world wide for the former VG9000, results not traceable to SI

28 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

29 How to get traceable results down to µg/kg level by GD-MS? - Preparation of powder samples of pure metal matrix doped with graduated contents of trace elements down to the ppb-level (µg/kg) -Pressing the powders at high pressure to metallic pellets of a size appropriate for the sample holder of GD-MS cell and compact enough to be sputtered by GD-MS without to be decayed. -Measurement of isotope ions of the analytes in medium mass resolution and simultaneous measurement of the signal of the matrix element. Calculation of the ion beam ratios (IBRs) of all measured isotopes related to the ion strength of the matrix. -Checking the linearity or monotony of the calibration curves based on these measurements. This is carried out for different sets of measurement values, starting with the lowest part of the calibration curve and ending with the curve including all contents, also the highest ones. -The best calibration curve for one special analysis includes only one point above the unknown content of the analytical sample.

30 Quantification with Element GD Semiquantitative Quantitative IBR = IBR I I E M H H E M w w E M Traceable to SI Standard RSF RSF Indirect Direct Std. RSF = y Fe RSF RSF y Zn Fe Zn w RSF E = IBR SRM E E Calibration with RM Calibration with doped pellets

31 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes o Matrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

32 Sample preparation of pressed powder pellets by doping with liquid standards (example Zn matrix) R. Matschat, J. Hinrichs and H. Kipphardt, Anal. Bioanal. Chem. 386:125 (2006) Doping 99,999% Zn powder 52 elements 1% HNO 3 Mix Shaking in three dimensions of space Press of ~ 1 g powder in steelrings under 90 kn/cm 2 Sample diameter 12 mm Thickness 2 mm Analysis 6

33 Sample preparation of pressed powder pellets by doping with liquid standards (example Zn matrix) Doping 99,999% Zn powder 52 elements 1% HNO 3 Press of ~ 1 g powder in steelrings under 90 kn/cm 2 Sample diameter 12 mm Thickness 2 mm Analysis 6

34 Observation of intensity-time behaviour of different elements Doped with powders: grain size between 3 and 900 μm 58 Ni 3-7 μm 1 ppm 123 Sb 70 μm 10 ppm 56 Fe > 840 μm 50 ppm Doped with liquids Pre-sputter time 24 Mg 5 ppm 64 Zn matrix 114 Cd 5 ppm Pre-sputter time Measurement time Measurement time Pre-sputter time Measurement time

35 Analytical parameters with Zn matrix Mass fractions of trace elements in the pellets 10 mg/kg; 5 mg/kg; 1 mg/kg; 500 µg/kg; 100 µg/kg; 50 µg/kg; 10 µg/kg; 5 µg/kg; blank Zn powder 99,999% pure <150 µm Parameters Voltage Current Ar Gas Flow ~500 V 20 ma 375 ml/min Peltier Cooling 20 C Low Resolution (LR) 400 Medium Resolution (MR) 4000 High Resolution (HR) 10000

36 Calibration with doped pellets

37 Calibration with doped pellets

38 Zn Certified Reference Materials Trace element mass fraction in mg/kg ± uncertainty mg/kg BAM-M601 ERM-EB322 ERM-EB323 ERM-EB324 Cd 0.55 ± ± ± ± 1.1 Fe 2.20 ± ± ± ± 1.6 Cu 1.89 ± ± ± ± 0.18 Tl 2.25 ± ± ± ± 0.5 Pb 15.7 ± ± ± ± 0.5

39 CRMs measurements

40 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

41 Quantification by Calibration with CRM Pure copper calibration set BAM-M Ni mass fraction from 0.73 µg/g to 25 µg/g R 2 = Nickel in copper IBR in ppm y = x RSF = mass fraction in µg/g certified [µg/g] measured [µg/g] BCR 074A 1.04 ± ± 0.14 BCR 075A 1.45 ± ± 0.05

42 Quantification by Calibration with CRM Mn mass fraction from 0.22 µg/g bis 13.3 µg/g IBR in ppm R 2 = Manganese in copper y = x RSF = mass fraction in µg/g certified [µg/g] measured [µg/g] BCR 074A 1.27 ± ± 0.04 BCR 075A 3.23 ± ± 0.29

43 Quantification by Calibration with CRM drawbacks: Indirectly traceable to SI (via measurement) only a few matrices availible especially for alloys often not availible in the necessary mass fraction range, especially mass fractions below 1 ppm are not accurately certified Use of doped and pressed powder samples doped with powders doped with solutions

44 Quantification by Calibration with doped pellets Homogeneity Observation of intensity-time behaviour of different elements Doped with powders: grain size between 3 and 900 micrometer 58Ni 3-7 µm 1 mg/kg 123Sb 70 µm 10 mg/kg 56Fe>840 µm 50 mg/kg

45 Mass fractions of analytes in the pressed copper and iron pellet samples doped with solutions: Samples of series A : µg/kg (ppb): Ag, Al, B, Ba, Bi, Ca, Cd, Co, Cr, Fe, Ga, In, K, Li, Mg, Mn, Na, Ni, Pb, Sr, Tl, Zn µg/kg (ppb): Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sc, Sm, Tb, Th, Tm, Y, Yb Samples of series B : µg/kg (ppb): As, Au, Hf, Ir, Mo, Nb, Os, Pd, Pt, Rh, Ru, Sb, Se, Sn, Ta, Te, Ti, V,

46 Quantification by Calibration with doped pellets Doped with solutions: standard solutions in diluted HNO 3 Mg24 Cu63 Pb206 Cd112 Ag107 Pb208

47 Copper matrix: Pressed multielement copper sample after GD analysis steel ring, outer diameter 30 mm; thickness 2 mm sputtered sample area inner diameter 12 mm redeposition ring wall ring area opposite to abutting face of theanodetube

48 Calibration Function of 205 Tl in Copper Matrix linear calibration y = 5E-10x + 2E-09 R 2 = 0,9887 7,0E-08 6,0E µg/kg 5,0E-08 ion beam ratio 4,0E-08 3,0E-08 2,0E-08 1,0E-08 0,0E+00-1,0E mass faction/ µg/kg (ppb)

49 Calibration Function of 205 Tl in Copper Matrix linear calibration y = 4E-10x + 7E-09 R 2 = 0,9968 5,0E-07 4,5E µg/kg 4,0E-07 3,5E-07 ion beam ratio 3,0E-07 2,5E-07 2,0E-07 1,5E-07 1,0E-07 5,0E-08 0,0E+00-5,0E mass fraction/ µg/kg (ppb)

50 Calibration Function of 205 Tl in Copper Matrix 6,0E-06 linear calibration y = 5E-10x - 1E-08 R 2 = 0,999 5,0E µg/kg 4,0E-06 ion beam ratio 3,0E-06 2,0E-06 1,0E-06 0,0E ,0E-06 mass fraction/ µg/kg (ppb)

51 Calibration Function of 45 Sc in Copper Matrix 4,0E-08 3,5E-08 linear calibration 0 10 µg/kg y = 3E-09x + 1E-09 R 2 = 0,9901 3,0E-08 ion beam ratio 2,5E-08 2,0E-08 1,5E-08 1,0E-08 5,0E-09 0,0E mass fraction/ µg/kg (ppb)

52 Calibration Function of 45 Sc in Copper Matrix linear calibration y = 3E-09x + 2E-09 R 2 = 0,9987 3,5E-07 3,0E µg/kg 2,5E-07 ion beam ratio 2,0E-07 1,5E-07 1,0E-07 5,0E-08 0,0E mass fraction/ µg/kg (ppb)

53 Calibration Function of 45 Sc in Copper Matrix linear calibration y = 3E-09x - 3E-09 R 2 = 0,9996 3,5E-06 3,0E µg/kg 2,5E-06 ion beam ratio 2,0E-06 1,5E-06 1,0E-06 5,0E-07 0,0E mass fraction/ µg/kg (ppb)

54 Linear correlation coefficients of calibration curves Matrix: Copper, 0 10 mg/kg (ppm) Ti205_MR Sr88_MR Pb208_a_MR (0) Ni60_a_MR (1x50) Na23_a_MR (100) Mn55_MR Mg24_a_MR (1X100) Li7_ M R K39_a_HR (100) In115_a_MR (100) Ga69_MR Fe56_a_MR (10) Cr52_MR Co59_MR C d 111_ M R Ca44_a_MR (10) Bi209_a_MR (0) Ba137_M R B 11_ M R Al27_a_MR (10) Ag109_a_M R (50) 0,993 0,994 0,995 0,996 0,997 0,998 0, ,001

55 Linear correlation coefficients of calibration curves Matrix: Copper, µg/kg (ppb) Yb172_MR Y89_a_MR (5+10) Tm169_MR Th232_MR Tb159_M R Sm152_a_MR (1 x 1) Sc45_MR Pr141_M R Lu175_ M R La139_a_MR (1) Ho16 5_ M R Gd158_MR Eu151_M R Er168_MR Er166_MR Dy162_MR Ce140_MR 0,9986 0,9988 0,999 0,9992 0,9994 0,9996 0,9998 1

56 100.0 Comparison of certified and measured values Matrix: Copper, FNE* ) CRMs Cu II/6, Cu II/8, Cu I/X * ) Research Institute for Nonferrous Metals, Mansfeld, Germany mass fraction/ mg/kg (ppm) certified measured Ag Cd Cd Co Co Ni

57 Comparison of certified and measured values Matrix: Copper, FNE* ) CRMs CuI/VI, Cu I/VIII * ) Research Institute for Nonferrous Metals, Mansfeld, Germany mass fraction/ mg/kg (ppm) certified measured Ag Ag Bi Cr Fe Mn Ni Ni Pb Pb Zn Zn

58 Comparison of certified and measured values Matrix: Copper, all measurements of FNE samples relative deviation = 100x(w mes -w cert )/ w cert [% rel ] certified value w cert [mg/kg (=ppm)]

59 Ag Al As Bi Quantification by Calibration with doped pellets certified µg/g ICP-MS µg/g LA-ICP-MS µg/g GD-MS µg/g using BAM CRMs as analytical samples BAM-M384 Cd Co Cr Fe Mg Mn Ni Pb Te Zn certified µg/g ICP-MS µg/g LA-ICP-MS µg/g GD-MS µg/g Ag Al As Bi Cd Co Cr Fe Mg Mn Ni Pb Te Zn [12.7] mass fraction in µg/g

60 Quantification by Calibration with doped pellets certified µg/g ICP-MS µg/g LA-ICP-MS µg/g GD-MS µg/g Ag Al BAM-M383 As Bi Cd Co Cr Fe Mg Mn Ni Pb Te Zn certified µg/g ICP-MS µg/g LA-ICP-MS µg/g GD-MS µg/g Ag Al [2.3] As Bi Cd Co Cr Fe Mg Mn Ni Pb Te Zn [7.8] mass fraction in ppm

61 Quantification by Calibration with doped pellets certified µg/g ICP-MS µg/g LA-ICP-MS µg/g GD-MS µg/g Ag Al BAM-M382 As Bi Cd Co Cr Fe Mg Mn Ni Pb Te Zn certified µg/g ICP-MS µg/g LA-ICP-MS µg/g GD-MS µg/g Ag Al < 2, As [0.6] Bi Cd Co Cr Fe Mg [1.4] Mn Ni Pb Te Zn mass fraction in µg/g

62 Quantification by Calibration with doped pellets certified µg/g ICP-MS µg/g LA-ICP-MS µg/g GD-MS µg/g Ag BAM-M381 Bi Co Fe Mn Ni certified µg/g ICP-MS µg/g LA-ICP-MS µg/g GD-MS µg/g Ag < Bi < Co < 0, Fe Mn Ni Pb Zn Pb Zn mass fraction in µg/g

63 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

64 Iron matrix: Pressed multielement sample and ultrapure massive sample Pressed powder sample after GD analysis Massive sample after GD analysis

65 Iron matrix: Pressed multielement iron sample after GD analysis steel ring, outer diameter 30 mm; thickness 2 mm sputtered sample area redeposited ring wall inner diameter 12 mm ring area opposite to abutting face of theanodetube R. Matschat, et al. T. Gusarova, B. Lange, H. Kipphardt, J. Hinrichs, U. Panne UHPM Deutsches Anwendertreffen Analytische Nagasaki, GDS, November Berlin, April

66 Calibration Function of 109 Ag in Iron Matrix 3,5E-08 3,0E-08 linear calibration µg/kg y = 3E-10x + 5E-09 R 2 = 0,9992 2,5E-08 ion beam ratio 2,0E-08 1,5E-08 1,0E-08 5,0E-09 0,0E mass fraction/ µg/kg (ppb)

67 Calibration Function of 109 Ag in Iron Matrix linear calibration y = 3E-10x + 5E-09 R 2 = E µg/kg 5.0E-07 ion beam ratio 4.0E E E E E mass fraction/ µg/kg (ppb)

68 Calibration Function of 165 Ho in Iron Matrix 7.0E E-08 linear calibration y = 1E-09x + 1E-09 R 2 = µg/kg 5.0E-08 ion beam ratio 4.0E E E E E mass fraction/ µg/kg (ppb)

69 Calibration Function of 165 Ho in Iron Matrix 7.0E E-07 linear calibration µg/kg y = 1E-09x + 3E-09 R 2 = >0, E-07 ion beam ratio 4.0E E E E E mass fraction/ µg/kg (ppb)

70 Linear correlation coefficients of calibration curves Matrix: Iron, (4000) µg/kg (ppb) Tl203_MR Sr88_MR Pb208_MR Ni60_MR (10) Na23_MR (0) Mn55_MR Mg24_MR Li7_ M R K39_HR In115_M R Ga69_MR Cu63_MR Cr52_MR Co59_MR C d 114 _ M R Bi209_MR (50) Ba138_MR (0) Ba138_MR B 11_ M R Al27_MR Ag109_MR 0,975 0,98 0,985 0,99 0, ,005

71 Linear correlation coefficients of calibration curves Matrix: Iron, µg/kg (ppb) Yb172_MR Y89_MR (0) Tm169_MR Th232_MR Tb159_MR (0) Sm152_MR Sc45_MR Pr141_MR Nd146_MR Lu175_MR La139_a_MR (0) Ho165_MR Eu153_MR Er168_MR Dy163_a_MR (0) Ce140_a_MR (0) 0,97 0,975 0,98 0,985 0,99 0,995 1

72 Comparison of certified and measured values Matrix: Iron, ECRMs 096-1, 097-1, mass fraction/ mg/kg (ppm) certified measured Cr Cu Cu Mn Mn Mo Nb Ni P P Pb Sn V

73 Comparison of certified and measured values Matrix: Iron, SRM mass fraction/ mg/kg (ppm) certified measured As B Cr Cu Mn Mo Nb P Ti V Zr

74 Comparison of certified and measured values Matrix: Iron, SRM 1762 mass fraction/ mg/kg (ppm) certified measured As B Co Cr Cu Mn Mo Nb Ni P Sn Ta Ti V Zr

75 Comparison of certified and measured values Matrix: Iron, SRM mass fraction/ mg/kg (ppm) certified measured As B Cr Cu Mn Mo Nb Ni P Ta Ti V

76 Comparison of certified and measured values Matrix: Iron, SRM 1765 mass fraction/ mg/kg (ppm) certified measured Ag As B Co Cr Cu Mn Mo Nb Ni P Pb Sb Sn Ti V

77 Comparison of certified and measured values Matrix: Iron, SRM mass fraction/ mg/kg (ppm) certified measured Ag Co Cr Cu Mn Mo Nb Ni P Pb Sb Sn Ti V

78 Comparison of certified and measured values Matrix: Iron, SRM 1767 mass fraction/ mg/kg (ppm) certified measured Ag As B Co Cu Mn Mo Nb Ni P Sb Sn Ti V

79 Comparison of certified and measured values Matrix: Iron, all measurements 50 relative deviation = 100x(w mes -w cert )/ w cert [% rel ] certified value w cert [mg/kg (=ppm)] 0,1 1,0 10,0 100,0 1000, , ,0

80 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

81 Determination of non-metals by GD-MS Why is it a problem? Determination of non-metallic analytes is much less sensitive than of metallic ones Reason: Their higher ionisation energies in comparison with metallic analytes 1st ionisation 1. Ionisierungspotential in in ev ev ev relative relative atomicatommasse mass in g/mol

82 Ionisation processes in GD-MS (1) (2) (3) (4) Cathode Dark Space Negative Glow (1) Charge Transfer (2) Penning Ionisation (3) Electron Ionisation (4) Recombination

83 Ionisation potential and metastable energies of He and Ar 1. 1st Ionisierungspotential ionisation in in ev ev He + 24,58 ev He* 19,82 ev 20,61 ev relative Atommasse in g/mol relative atomic mass Ar + Ar* 11,72 ev 11,55 ev

84 Enhancement of analytical signals of phosphorus in copper by addition of He gas to the Ar plasma gas Zusatz von He (P) intensity Intensität in in cps cps Each step = addition of 25 ml/min He (330 ml/min Ar, 50 ma) Zeit time in in min min

85 Signal enhancement by changing discharge current or discharge gas Carbon (IP ev): Ar: 370 ml/min DC:50 ma Ar: 370 ml/min DC:60 ma Ar: 365 ml/min He: 100 ml/min DC:50 ma Increase of peak about: 25 % 1500 %

86 Signal enhancement by changing discharge current or discharge gas Chlorine (IP 12,96 ev): Ar: 370 ml/min DC:50 ma Ar: 370 ml/min DC:60 ma Ar: 380 ml/min He: 100 ml/min DC:50 ma Increase of peak about: 40 % 4500 %

87 Signal enhancement by changing discharge current or discharge gas Fluorine (IP 17,42 ev): Ar: 380 ml/min DC:50 ma Ar: 380 ml/min DC:60 ma Ar: 380 ml/min He: 100 ml/min DC:50 ma Increase of peak about: 40 % 350 %

88 Signal enhancement by changing discharge current or discharge gas Nitrogen (IP 14,53 ev): Ar: 380 ml/min DC:50 ma Ar: 380 ml/min DC:60 ma Ar: 375 ml/min He: 100 ml/min DC:50 ma Increase of peak about: 20 % 4000 %

89 Signal enhancement by changing discharge current or discharge gas Oxygen (IP 13,62 ev): Ar: 370 ml/min DC:50 ma Ar: 370 ml/min DC:60 ma Ar: 315 ml/min He: 100 ml/min DC:50 ma Increase of peak about: 10 % 800 %

90 Signal enhancement by changing discharge current or discharge gas Phosphorus (IP 10,49 ev): Ar: 370 ml/min DC:50 ma Ar: 370 ml/min DC:60 ma Ar: 370 ml/min He: 100 ml/min DC:50 ma Increase of peak about: 30 % 200 %

91 Signal enhancement by changing discharge current or discharge gas Sulphur (IP 10,36 ev): Ar: 365 ml/min DC:50 ma Ar: 365 ml/min DC:60 ma Ar: 355 ml/min He: 100 ml/min DC:50 ma Increase of peak about: 30 % 250 %

92 Comparison of CRM based calibration curves with and without He discharge gas intensity in cps phosphorus in copper matrix Phosphorus y = 12190x R 2 = 1 b) a) y = 6041x R 2 = 0, mass fraction in mg/kg Conditions: 52 ma 325 ml/min Ar 90 ml/min He 60 ma 370 ml/min Ar increase of slope absolute sensitivity doubled calibration points meet the straight line

93 Comparison of calibration curves based on doped pressed powder pellets (5 µg/kg 100 µg/kg) with and without He discharge gas phosphorus in copper matrix without He gas R 2 = 0, intensity in cps ,02 0,04 0,06 0,08 0,1 0,12 mass fraction in mg/kg intensity in cps R 2 = 0,9999 with He gas 0 0 0,02 0,04 0,06 0,08 0,1 0,12 mass fraction in mg/kg

94 Comparison of CRM based calibration curves with and without He discharge gas sulphur in copper matrix intensity in cps Sulphur y = 28733x R 2 = 0,9998 y = 9939x R 2 = 0, mass fraction in mg/kg b) a) Conditions 60 ma 310 ml/min Ar 140 ml/min He 60 ma 355 ml/min Ar increase of slope absolute sensitivity higher (nearly factor three) calibration points meet the straight line

95 Comparison of calibration curves based on doped pressed powder pellets (5 µg/kg 1000 µg/kg) with and without He discharge gas sulphur in copper matrix without He gas R 2 = 0,1647 intensity in cps R 2 = 0,9997 with He gas 0 0 0,2 0,4 0,6 0,8 1 1,2 mass fraction in mg/kg intensity in cps ,2 0,4 0,6 0,8 1 1,2 mass fraction in mg/kg

96 Content Why Primary Pure Standards? BAM System of Primary National Standards Way of certification, some results Need for GD-MS GD-MS and Element GD Element-GD Traceable results for metallic analytes omatrix zinc o Matrix copper o Matrix iron Traceable results for non-metallic analytes Conclusions

97 Conclusion I The necessity of Primary Pure CRMs as National Standards for Elemental Analysis is evident The BAM system of such materials is in progress together with a system for national dissimination (in co-operation with PTB) The materials will be only be distributed to NMIs or signatories of MRA

98 Conclusion II GD-MS is a powerful tool for multielement ultra-trace determination of metallic analytes and using Ar/He mixtures as plasma gas - also for non-metallic analytes The new ELEMENT GD spectrometer combined with the special preparation and application of doped pressed powder pellets offers an important completion to achieve traceable results for Primary Pure CRMs and other high purity metals

99 The authors say many thanks to all concerned colleagues from BAM for their valuable contributions and thank you for your attention!