基于色谱分离的不同价态锑同位素分析的前处理方法  

Development of Pre-treatment Methods for Analysis of Different Oxidation States of Antimony Isotopes Based on Chromatographic Separation

作　　者：韩适 孙广义 李欣宇 冯新斌[1,4] HAN Shi;SUN Guang-Yi;LI Xin-Yu;FENG Xin-Bin(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;School of Earth Sciences,China University of Geosciences(Wuhan),Wuhan 430074,China;Science Unit,Lingnan University,Hong Kong 999077,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地球化学研究所,环境地球化学国家重点实验室,贵阳550081 [2]中国地质大学(武汉)地球科学学院,武汉430074 [3]岭南大学科学教研组,中国香港999077 [4]中国科学院大学,北京100049

出　　处：《分析化学》2024年第10期1536-1543,共8页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No.41921004);贵州省科技支撑计划项目(No.黔科合支撑[2023]一般252)资助。

摘　　要：锑(Sb)是一种有毒的金属元素,不同价态的锑在环境中的迁移、转化及行为模式也不同。为了深入研究锑及其化合物在地球表生生态环境中的地球化学循环,准确测定不同价态的同位素组成至关重要。本研究建立了一种通过色谱分离并结合多接收电感耦合等离子体质谱测定水体样品中不同价态同位素组成的前处理方法,并成功用于天然雨水样品和晴隆矿区地下水样品中Sb的测定。在前处理过程中,采用5 mmol/L乙二胺四乙酸二钾盐(EDTA)和2 mmol/L邻苯二甲酸氢钾(KHP)的混合溶液(pH 4.5)作为流动相,通过Hamilton PRP-X100阴离子交换色谱柱分离水体样品中的Sb(Ⅲ)和Sb(Ⅴ),利用一系列单因素实验确定最佳分离条件为:柱温40℃,高效液相泵流速1.5 mL/min。结果表明,色谱柱分离前后,Sb(Ⅲ)和Sb(Ⅴ)溶液以及混合价态标准溶液中的Sb(Ⅲ)和Sb(Ⅴ)的回收率分别为99%±1%、103%±1%以及106%±1%、101%±1%,并且不同价态的同位素组成在通过色谱柱前后保持不变。此外,在天然雨水样品中添加不同价态的锑标准溶液,验证了本方法的可靠性。本研究为深入研究锑及其化合物在地球表生生态环境中的地球化学循环提供了重要的技术支撑。Antimony is a toxic metalloid and exhibits different geochemical properties in different valence states,leading to distinct migration,transformation,and behavioral patterns in the environment.To further study the transfer and source-sink relationship of antimony and its compounds in the earth′s surface ecological environment,it is very important to accurately determine the isotopic composition of antimony with different speciations.In this study,a pretreatment method for chromatographic separation and determination of different speciation′s antimony isotopes in water samples was established by using multi-collector inductively coupled plasma mass spectrometry(MC-ICP-MS)to measure the isotopic composition of different speciation′s antimony.This method was successfully applied to detection of natural rainwater and groundwater samples from the Qilong mining area.During the pretreatment,5 mmol/L ethylenediaminetetraacetic acid dipotassium salt(EDTA)and 2 mmol/L potassium hydrogen phthalate(KHP)(pH 4.5)were used as mobile phase,successfully separating trivalent antimony(Sb(Ⅲ))and pentavalent antimony(Sb(V))from water samples using a Hamilton PRP-X100 anion exchange chromatographic column.A series of single-factor experiments identified the optimal separation and determination conditions as a column temperature of 40℃and a high-performance liquid pump flow rate of 1.5 mL/min.The recoveries of Sb(Ⅲ)and Sb(V)from the standard solutions of Sb(Ⅲ)and Sb(Ⅴ),and the mixed oxidation states solutions were 99%±1%,103%±1%,106%±1%,and 101%±1%,respectively.Moreover,the isotopic compositions of different speciation′s antimony remained consistent before and after the chromatographic column treatment,and the reliability of the method was verified by detecting different oxidation state antimony in the natural rainwater samples.This research might provide important technical support for further studies on the geochemical cycling of antimony and its compounds in the ecological environment of the Earth′s surface.

关 键 词：锑 锑同位素 价态分离 测试 多接收电感耦合等离子体质谱 高效液相色谱 

分 类 号：O657.63[理学—分析化学] X830[理学—化学]