Institute for National Measurement Standards, National Research Council Canada, Ottawa, Ontario, K1A 0R6, Canada.
Anal Chem. 2011 Dec 1;83(23):8999-9004. doi: 10.1021/ac201795v. Epub 2011 Nov 10.
Multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) suffers large bias in isotope amount ratio determinations which has to be properly accounted for. The choice of the proper discrimination model is crucial. Over the last few decades, the exponential mass-bias correction model (Russell's law) has become a standard curriculum in isotope amount ratio measurements. In nature, however, isotopic fractionation that deviates significantly from the exponential model has been known for a long time. Recently, such fractionation was also observed in MC-ICPMS. This phenomenon is termed mass-independent fractionation. In this study, significant departure from the mass-dependent fractionation model is reported for germanium and lead with the most dramatic occurring for germanium-73 and lead-204 isotopes wherein, on average, close to a half percent bias was evidenced from the Russell's law.
多接收电感耦合等离子体质谱 (MC-ICPMS) 在同位素丰度比测定中存在较大的偏差，需要进行适当的校正。选择合适的甄别模型至关重要。在过去的几十年中，指数质量偏差校正模型（Russell 定律）已成为同位素丰度比测量的标准课程。然而，在自然界中，长期以来人们已经知道，同位素分馏明显偏离指数模型。最近，这种分馏也在 MC-ICPMS 中观察到。这种现象被称为质量无关的分馏。在这项研究中，报道了锗和铅的质量相关分馏模型的显著偏离，其中最显著的是锗-73 和铅-204 同位素，平均而言，从 Russell 定律中可以明显看出近半%的偏差。
