The Journal of the Petrological Society of Korea (암석학회지)

The Petrological Society of Korea (한국암석학회)
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Rapid and Precise Determination of Pb Isotope Ratios Using Mu1ti-Collector ICP/MS

다검출기 유도결합 플라즈마 질량분석기를 이용한 신속하고 정밀한 Pb 동위원소 분석

  • 최만식 (한국기초과학지원연구원 동위원소분석팀) ;
  • 정창식 (한국기초과학지원연구원 동위원소분석팀) ;
  • 신형선 (한국기초과학지원연구원 동위원소분석팀) ;
  • 임태선 (한국기초과학지원연구원 동위원소분석팀)
  • Published : 2001.12.01
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Abstract

This study investigated the effects of Pb/Tl ratio, Pb concentration and concomitant matrix elements on the measurement of Pb isotope ratios using multi-collector ICP/MS (AXIOM MC model). Accuracy and reproducibility of Pb isotope ratios in NBS 981 solution were estimated for 42 data measured from March to August 2001. Pb isotopes measured in rocks, bronzes and sediments were compared to data measured by TIMS. Reproducibilities for $^{206}Pb/^{204}Pb,\; ^{207}Pb/^{204}Pb,\;and\;^{208}Pb/^{204}Pb$ ratio were about 500 ppm (2sd) and for $^{207}Pb/^{206}Pb$\;and\;^{208}Pb/^{206}Pb$ were 100~200 ppm for 200 ng of Pb in NBS 981 solution. The optimum conditions for the analysis of Pb isotope ratios with AXIOM MC for best accuracy and reproducibility were defined as follows; 1) Pb/Tl ratio is about 10 2) Pb concentration is about 100 ng/ml 3) correction for mass discrimination is performed by exponential law using 2.3887 of $^{205}Tl/^{203}Tl$ and Pb mass fractionation factor empirically obtained from $ln(^{208}Pb/^{206}Pb)-ln(^{205}Tl/^{203}Tl)$ relationship. The sample data measured with MC/ICP/MS for acid-digested and chemically separated rock samples, and acid-digested bronze samples and sediment samples coincide with those of TIMS within analytical errors. Therefore, MC/ICP/MS is a rapid analytical technique for Pb isotope ratios with the similar precision compared with TIMS.

다검출기 유도결합 플라즈마 질량분석기(Multi-Collector Inductively Coupled Plasma Mass Spectrometer; MC/ICP/MS; AXIOM MC 모델)를 이용한 Pb동위원소 분석 시 고려 사항인 Pb/Ti 비율, Pb농도 영향, 기질 원소 영향을 살펴보고, NBS 981 용액을 2001년 3월부터 8월까지 42번 측정하여 정확도 및 재현성 을 검토하였다. 그리고 암석, 청동기 및 퇴적물 시료의 Pb 동위원소를 분석하여 열 이온화 질량분석기(TIMS) 자료와 비교하였다. NBS 981 Pb 200 ng으로 동위원소 비율을 측정하였을 때 $^{206}$ $Pb^{204}$ , $Pb^{207}$ //$Pb^{204}$ , $Pb^{208}$ $Pb^{204}$ Pb 비율은 약 500 ppm(2sd), $^{/}$$207^{206}$ Pb 및 $Pb^{208}$ $Pb^{206}$Pb 비율은 100~200 ppm(2sd)의 재현성을 얻을 수 있었다. Pb등위원소 분석의 정확도 및 재현성 측면에서 최적 조건은 1) Pb/Tl농도 비가 10 이고 2) Pb농도가 100 ng/ml 이상이며 3) 질량 분별 효과는 지수 법칙에 따라 보정하고 이 때 사용된 Tl의 동위원소 비율($^{205}$ $Tl^{203}$ Tl)은 2.3887이며 질량 분별 인자는 측정된 $208^{Pb}$ $^{206}$ 및 $Pb^{205}$ $Tl^{203}$ Tl 비율로부터 경험적으로 구해진 Pb의 인자를 이용하는 것이었다. 시료 중의 기질 원소들(matrix elements)에 의한 Pb 동위원소 비율의 영향은 없는 것으로 판단되며, TIMS와 비교된 시료들에 대하여 Pb 등위원소들은 측정 오차 범위 내에서 잘 일치하였다. 즉, MC/ICP/MS에 의한 Pb 동위원소 분석은 시료 전처리 단계를 줄여도 WS와 유사한 정밀도를 얻을 수 있어 신속한 분석방법이라 할 수 있다.다.

Keywords

References

  1. Inter. J. Mass Spectrom. v.181 A new variable dispersion double-focusing plasma mass spectrometer with performance illustrated for Pb isotopes Belshaw, N.S.;Freedman, P.A.;O'Nions, R.K.;Frank, M.;Guo, Y.
  2. Inter. J. Mass Spectrom. v.197 High precision measurement of iron isotopes by plasma source mass spectrometry Belshaw, N.S.;Zhu, X.K.;Guo, Y.;O'Nions, R.K.
  3. J. Res. NBS v.72A Absolute isotopic abundance ratios of common, equal-atom and radiogenic lead isotopic standards Catanzaro, E.J.;Murphy, T.J.;Shields, W.R.;Garner, E.L.
  4. Radiogenic Isotope Geology Dickin, A.P.
  5. J. Res. Natl. Bur. Stand. v.85 Absolute isotopic abundance and the atomic weight of a reference sample of thallium Dunstan, L.P.;Gramlich, J.W.;Barnes, I.L.;Purdy, W.C.
  6. Geochim. Cosmochim. Acta v.62 no.6 Applications of multiple collector-ICPMS to cosmochemistry. geochemistry, and paleoceanography Halliday, A.N.;Lee, D.-C.;Christensen, J.N.;Rehkamper, M.;Yi, W.;Luo, X.;Hall, C.M.;Ballentine, C.J.;Pettke, T.;Stirling, C.
  7. The Analyst v.121 Lead isotopic analysis of NIST standard reference materials using multiple collector- inductively coupled plasma mass spectrometry coupled with modified external correction method for mass discrimination effect Hirata, T.
  8. J. Kor. Ocean. Soc. v.35 no.4 Geochemistry of Pb in surface sediments of the Yellow Sea: Contents and Speciation Kim, K.T.;Shin, H.S.;Lim, C.R.;Cho, Y.G.;Hong, G.H.;Kim, S.H.;Yang, D.B.;Choi, M.S.
  9. Spectrochim. Acta. v.42B Determination of lead isotope ratios by inductively coupled plsama mass spectrometry (ICP-MS) Longerich, H.P.;Fryer, B.J.;Strong, D.F.
  10. Chem. Geol. v.156 Precise analysis of copper and zinc isotopic compositions by plasma-source mass spectrometry Marechal C.N.;Telouk, P.;Albarede F.
  11. Geochem. Geophy. Geosys. v.1 Abundance of zinc isotopes as a marine biogeochemical tracer Marechal, C.N.;Nicolas, E.;Douchet, C.;Albarede, F.
  12. J. Geophy. Res. v.99 no.D2 Lead isotope ratios of airborne particulate matter as tracers of long-range transport of air pollutants around Japan Mukai, H.;A. Tanaka;T.Fujii;M. Nakao
  13. Inter. J. Mass Spectrom v.181 Accuracy and long-term reproducibility of lead isotopic measurements by multiple-collector inductively coupled plasma mass spectrometry using an external method for correction of mass discrimination Rehkamper, M.;Halliday, A.N.
  14. Geochim. Cosmochim. Acta v.63 no.6 The precise measurement of Tl isotopic compositions by MC-ICPMS: Application to the analysis of geological materials and mateorites Rehkamper, M.;Halliday, A.N.
  15. J. Anal. At. Spectrom v.15 Investigation of matrix effects for Pb isotope ratio measurements by multiple collector ICP-MS: verification and application of optimized analytical protocols Rehkamper, M.;Mezger, K.
  16. Geochem. Geophy. Geosys v.2 Determination of molybdenum isotope fractionation by double-spike multicollector inductively coupled plasma mass spectrometry Siebert, C.;Nagler, T.F.;Kramers, J.D.
  17. J. Anal. At. Spectrom. v.10 validation of the analytical linearity and mass discrimination correction model exhibited by a multiple collector inductively coupled plasma mass spectrometer by means of a set of synthetic uranium isotope mixtuires Taylor, P.D.P.;Bievre, P.D.;Walder, A.J.;Entwistle, A.
  18. Chem. Geol. v.163 Inter-laboratory and other errors in Pb isotope analyses investigated using a $^{207}Pb-^{204}Pb$ double spike Thirlwall, M.F.
  19. Am. Geophys. Union Evaluation of a $^{202}Pb-^{205}Pb$ double spike for high-precision lead isotope analysis. In Earth Processes: Reading the Isotopic Code Todt, W.;Cliff, R.A.;Hanser, A.;Hofmann, A.W.;Basu, A.R.(ed.);Hart, S.R.(ed.)
  20. Advanced isotope ratio mass spectrometry Ⅱ: isotope rtio measurement by multiple collector inductively coupled plsma mass spectrometry Modern Isotope Ratio Mass Spectrometry Walder, A.J.;Platzner I.T.(ed.)
  21. Anal. Sci. v.9 High-precision lead isotope ratio measurement by inductively coupled plasma multiple collector mass spectrometry Walder, A.J.;Furuta, N.
  22. Chem. Geol. v.167 High-precision analysis of Pb isotope ratios by multi-collector ICP-MS White, W.M.;Albarede, F.;Telouk, P.