置换液液分散微萃取测定水样中的痕量镉

Application of Displacement Dispersive Liquid-liquid Microextraction for Trace Cadmium in Environmental Water Samples

首次采用置换液液分散微萃取法分离富集环境水样中痕量镉。在实验中,分别对萃取剂、分散剂、被置换剂的种类、配合剂二乙基二硫代氨基甲酸钠(DDTC)的浓度、水-分散剂-有机萃取剂三者的体积比,以及溶液的酸度进行了优化。得到的最佳实验条件为:在pH 6左右时,四氯化碳、丙酮、Zn^(2+)分别为萃取剂、分散剂和被置换剂,DDTC配合浓度为0.003%,水相、丙酮和四氯化碳的体积分别为5.00、0.50 mL和90μL。在上述确定的实验条件下,成功测定了复杂水样中痕量镉,方法的检出限为0.005μg/L,回收率为92.5%~109%。

In this work,displacement dispersive liquid-liquid microextraction（D-DLLME） has been developed for the analysis of cadmium in complex matrix for the first time.Extracting agent,dispersant,displacement agent were selected,and the concentration of sodium diethyldithiocarbamate（DDTC）,the volume ratio of water,dispersant,organic phase,and solution acidity were optimized.The optimal experimental conditions were obtained.pH 6,the extracting agent,dispersant,displacement agent was selected the carbon tetrachloride,acetone and Zn^（2＋）.0.003% DDTC,the volume of water,dispersant,organic phase was 5.00 mL,0.50 mL and 90 μL.The method was developed in complex matrix,and the detection limit was 0.005 μg/L.The recovery rate was from 92.5% to 109%.