动态反应池-电感耦合等离子体质谱法直接测定高盐氯化钙型地下水中的痕量总砷  

Determination of Arsenic in High Salinity and Calcium Chloride Type Groundwater by Dynamic Reaction Cell-Inductively Coupled Plasma Mass Spectrometry

作　　者：张江义[1] 郭伟[2] 李国敏[1] 

机构地区：[1]中国科学院地质与地球物理研究所,中国科学院工程地质力学重点实验室,北京100029 [2]生物地质与环境地质国家重点实验,中国地质大学(武汉),武汉430074

出　　处：《分析化学》2013年第12期1915-1918,共4页Chinese Journal of Analytical Chemistry

基　　金：国家重点基础研究发展计划(No.2010CB428801);国家自然科学基金(No.21207120)资助

摘　　要：采用O2作为反应气,将75As+氧化成75As16O+后在m/z 91处测定,有效消除了m/z 75处40Ar35Cl+,40Ca35Cl+,39K36Ar+形成的质谱干扰,建立了电感耦合等离子体质谱法(ICP-MS)直接测定高盐氯化钙型地下水中痕量总砷的方法。优化了反应池(DRC)的参数,在O2流速为0.1 mL/min,反应池抑制参数R pq=0.55时,背景等效浓度(BEC)最小。样品中加入3%甲醇可以提高75As16O+的信号强度3.6倍。方法采用海水标准物质NASS-4和CASS-5进行了验证,结果令人满意。方法的检出限为0.01μg/L,1.0μg/L As的7次平行测定的相对标准偏差为1.8%。A new procedure for the direct determination of total arsenic in high salinity and CaCl2 type groundwater has been developed. In order to remove the polyatomic interferences 40Ar35Cl＋,40Ca35Cl＋,39K36Ar＋ arising from the direct analysis of high salinity and CaC12 type groundwater, 75As＋, the mass for general detection, was effectively changed to 75As160＋ which could be detected at m/z 91 by reaction with oxygen in a Dynamic Reaction Cell （DRC）. The DRC parameters were optimized, the background equivalent concentration （BEC） was minimum when 02 gas flow rate was 0. 1 mL/min and the rejection parameter q （RPq） of DRC was 0.55. The signal intensity of 75As160＋ was improved 4-fold by addition of 3% methanol into sample solution. The accuracy was verified by the analysis of certified reference materials of sea-water （CASS-5, NASS-4）. Detection limits of 0. 011μg/L and the relative standard deviation of 1.8% were obtained.

关 键 词：电感耦合等离子体质谱 总砷 氯化钙 高盐地下水 

分 类 号：O657.63[理学—分析化学]