浊点萃取-石墨炉原子吸收光谱法测定药物胶囊中的痕量铬(Ⅵ)

Determination of Chromium(Ⅵ)in Drug Capsules by Graphite Furnace Atomic Absorption Spectrometry after Cloud Point Extraction

采用硝基苯胲铵盐(铜铁试剂)、吡咯烷基二硫代甲酸铵(APDC)为络合剂,T riton X-114为表面活性剂的浊点萃取体系分别富集药物胶囊中的痕量Cr(Ⅲ)和总铬,富集后的Cr(Ⅲ)和总铬用石墨炉原子吸收光谱法进行测定。讨论了溶液pH值、表面活性剂浓度、络合剂浓度、平衡温度、平衡时间等对浊点萃取效率的影响。在优化的实验条件下,铬(Ⅵ)的检出限为0.031Lg/L,相对标准偏差为1.2%(C=2.0Lg/L,n=6),加标回收率为98.4%—102.1%。应用该法测定药物胶囊中的痕量Cr(Ⅵ),结果令人满意。

A method was developed for the determing trace amount of Cr （VI） and total chromium in drug capsules by graphite furnace atomic absorption spectrometry after cloud point extraction with cupferron and ammonium pyrrolidine dithiocarbamate （APDC）. The main factors affecting the cloud point extraction,such as pH,concentrations of APDC,cupferron and triton X-114, reaction temperature and time were studied. Under the optimal conditions,the detection limit of Cr （ Ⅵ ）is 0. 031μg/L（S/N=3） with RSD of 1.2% （C=2.0μg/L,n=6）. The method has been applied to the determination of Chromium in drug capsules samples with satisfactory recoveries ranging from 98.4%o to 102.1%.