离子色谱-电感耦合等离子体质谱法灵敏分析环境水样中的碘形态  

A Sensitive Ion Chromatography-Inductively Coupled Plasma Mass Spectrometry Method for Analysis of Iodine Speciation in Environmental Water Samples

作　　者：姜欢 陈宁[1] 王妍芸 范煜坤[1] 张梦婷 张路远[1] 侯小琳[1] JIANG Huan;CHEN Ning;WANG Yan-Yun;FAN Yu-Kun;ZHANG Meng-Ting;ZHANG Lu-Yuan;HOU Xiao-Lin(Xi′an Accelerator Mass Spectrometry Center,State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi′an 710061,China;Xi′an Institute for Innovation Earth Environment Research,Xi′an 710061,China)

机构地区：[1]中国科学院地球环境研究所,黄土与第四纪地质国家重点实验室,西安加速器质谱中心,西安710061 [2]西安地球环境创新研究院,西安710061

出　　处：《分析化学》2025年第2期278-288,共11页Chinese Journal of Analytical Chemistry

基　　金：中国科学院重点部署项目(No.ZDBS-SSW-DQC003);中国科学院"西部之光"项目(No.XAB2022YN01)资助。

摘　　要：碘在水环境中的形态极易受溶解氧含量、氧化还原电位、微生物活动、有机质分解和光反应等共同影响,对环境水体中碘形态的准确定量分析不仅可以了解碘的地球化学循环,还可以示踪环境变化过程。本研究基于离子色谱(IC)与电感耦合等离子体质谱(ICP-MS)联用,针对海水、河水、湖水、雨水和地下水等环境水体中碘的形态组成,建立了一种快速、灵敏的环境水样中碘形态的分析方法。通过使用色谱保护柱AG22(50 mm×4 mm),采用8 mmol/L(NH4)2CO3为流动相,可在120 s内快速分离海水样品的IO_(3)^(-)及I^(-);对可溶性有机碘(SOI)含量较高的湖水、河水及降水样品,在保护柱后串接柱效更高的AS22分离柱(250 mm×4 mm),采用50 mmol/L(NH_(4))_(2)CO_(3)为流动相,将SOI与IO_(3)^(-)完全分离,实现了IO_(3)^(-)的准确定量分析。通过直接将内标同位素^(133)Cs加入到(NH_(4))_(2)CO_(3)流动相中,实现了碘测量信号波动的准确校正。通过测量的总碘与I^(-)和IO_(3)^(-)加和的差值获得了SOI含量。本研究建立的碘形态分析方法的精密度<3.5%,标准加入法实验结果表明本方法分析准确可靠。对于25μL的进样体积,IO_(3)^(-)及I^(-)的检出限分别为0.011~0.025μg/L和0.023~0.031μg/L。本方法可用于海水、河水、雨水和地下水等环境水样中IO_(3)^(-)、I^(-)和SOI的分析。Iodine speciations in aquatic environments are affected by dissolved oxygen,redox potential,microbial activity,organic matter decomposition,light reaction,etc.Accurate quantification of iodine speciation can not only help to understand the geochemical cycle of iodine,but also help to trace and study environmental processes.Based on the combination of ion chromatography(IC)and inductively coupled plasma mass spectrometry(ICP-MS),a rapid and sensitive method was established for determining the speciations of iodine in environmental water samples including seawater,river water,lake water,rainwater,groundwater,etc.The results presented here showed that IO_(3)^(-)and I^(-)in seawater were quickly separated and measured within 120 s when using guard column AG22 and 8 mmol/L(NH_(4))_(2)CO_(3)as the mobile phase.While for lake water,river water and precipitation samples with high soluble organically bond iodine(SOI),an AS22 separation column(250 mm×4 mm)connected with a guard column and using 50 mmol/L(NH_(4))_(2)CO_(3)as mobile phase could effectively separate unknown SOI from IO_(3)^(-)to achieve accurate quantification of IO_(3)^(-).For accurate correction of iodine measurement signal fluctuations,^(133)Cs was directly added to the(NH4)2CO3 mobile phase as an internal standard.The SOI content was calculated by the total iodine concentrations minus the sum of IO_(3)^(-)and I^(-).The precision of the established iodine speciation analytical method was better than 3.5%,and the standard addition experiment showed that the analytical method was accurate.When the injection volume was 25μL,the detection limits were 0.011-0.025μg/L for IO_(3)^(-)and 0.023-0.031μg/L for I^(-),respectively.The method was successfully used to analyze IO_(3)^(-),SOI and I^(-)in environmental water samples,such as seawater,river water,rainwater and groundwater.

关 键 词：离子色谱 电感耦合等离子体质谱 碘形态 环境水样 铯-133内标 

分 类 号：O657.63[理学—分析化学] X832[理学—化学]