浊点萃取-热喷雾火焰炉原子吸收光谱法测定水中痕量锌(Ⅱ)

Cloud point extraction coupled with thermospray flame furnace atomic absorption spectrometry for the determination of zinc(Ⅱ) in water samples

建立了以吡咯烷二硫代氨基甲酸铵(APDC)为络合剂、TritonX-100为表面活性剂的浊点萃取-热喷雾火焰原子吸收光谱法测定水样中痕量锌的方法。考查了APDC的浓度、溶液酸度、表面活性剂浓度、加热时间、水浴温度、干扰离子等实验条件对浊点萃取效率的影响。在最优化的实验条件下,方法的检出限为0.1 ng/mL,RSD为4.3%,富集系数为22。可用于水样中的痕量锌的测定。

A sensitive method based on cloud point extraction（CPE） for separation/preconcentration and thermospray flame furnace atomic absorption spectrometry（TS-FF-AAS） was proposed for the determination of ultratrace zinc in water samples.The analytical procedure involved the formation of analyte-entrapped surfactant micelles by mixing the analyte solution with an ammonium pyrrolidine dithiocarbamate（APDC） solution and a TritonX-100 solution.Some parameters that influenced extraction and determination were evaluated in detail,such as the concentration of ammonium pyrrolidine dithiocarbamate（APDC）,pH of samples,the concentration of TritonX-100,extraction time,as well as interferences.Under optimized conditions,an enrichment factor of 22 could be obtained,and the limit of detection was 0.1 ng/mL.The relative standard deviation（RSD） for 11 replicate determinations of 1.0 ng/mL Zn2＋ was 4.3%.Finally,the proposed method was successfully applied to the determination of zinc in water samples.