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.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
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
关键词
电感耦合等离子体质谱
总砷
氯化钙
高盐地下水
Inductively coupled plasma mass spectrometry
Arsenic
Calcium chloride type groundwater
High salinity groundwater
