Optimizing the ratio of the spike to sample for isotope dilution analysis:a case study with selenium isotopes

作     者：Decan Tan Wenpo Xu Zuochen Zhu Shehong Li Guangliang Wu Haibo Qin Decan Tan;Wenpo Xu;Zuochen Zhu;Shehong Li;Guangliang Wu;Haibo Qin

作者机构：State Key Laboratory of Environmental GeochemistryInstitute of GeochemistryChinese Academy of SciencesGuiyang 550081China University of Chinese Academy of SciencesBeijing 100049China Beijing 21st Century International SchoolBeijing 100014China State Key Laboratory of Geological Processes and Mineral ResourcesChina University of GeosciencesBeijing 100083China 

出 版 物：《Acta Geochimica》 (地球化学学报（英文）)

年 卷 期：2020年第39卷第2期

页      面：192-202页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 070301[理学-无机化学] 

基　　金：supported by Natural Science Foundation of China(No.U1612441 41673017) 

主　　题：Isotope dilution method Error propagation Mento Carlo Se concentration Geological reference materials 

摘      要：Isotope dilution(ID)method has been widely applied to studies of elemental speciation and certification of the concentrations of geological reference *** of the key factors restricting the application of the ID method is the difficulty in identifying the optimal ratios of the isotope tracer(spike)to sample(S/N)and in estimating the error ***,using Se isotope as an example and employing a Monte Carlo method,we found that the optimal choice of spike and S/N are^(77)Se(spike)and 0.7,*** S/N in the range from 0.1 to 4 can produce sufficiently low errors(0.4%).Extending this method to other elements such as Cr,Fe,Ni,Sr,Cd and etc.,their optimal spike and S/N were also *** to the optimized parameters of Se,we determined the Se concentrations of geological reference materials(GRMs)by thiol cotton fiber(TCF)-hydride generation *** relative standard deviation is5%,and the detection limit is reduced to0.1 ng/*** of the measured concentrations are consistent with those recommended by IGGE or reported *** some GRMs,discrepancies(e.g.6.90%for GSS-5)exist between our measurements and previous ones,which can be explained by the inhomogeneity of GRMs and/or the different digestion,purification and measurement methods among laboratories.