基于分散剂乙醇(0.5 mL)和萃取剂四氯化碳(30 μL)的协同作用,可使水样(5.0 mL)中痕量铅(Ⅱ)与吡咯烷基二硫代氨基甲酸铵(APDC,0.012 g·L-1)所形成的螯合物,在pH 7.0及55 ℃的条件下迅速借分散液相微萃取(DLLME)进入四氯化碳的液滴中,从而达到样品中痕量铅的分离与富集。其含量用连续光源石墨炉原子吸收光谱法予以测定。铅的线性范围在1.00~40.00 μg·L-1之间,其检出限(3s/k)为0.15 μg·L-1。应用本法测定了自来水和河水中痕量铅,加标回收率在96.8%~105%之间,测定值的相对标准偏差(n=10)均小于5%。

Based on the coordinated action of the dispersant-ethanol (0.5 mL) and the extraction solvent-CCl4 (30 μL), the chelate formed between Pb(Ⅱ) in water sample (5.0 mL) and the extractant-APDC (0.012 g·L-1) was extracted rapidly into the droplets of CCl4, under the conditions of pH 7.0 and 55 ℃ by DLLME, thus rendering enrichment of traces of Pb(Ⅱ) from the water sample. Content of traces of Pb(Ⅱ) in water was finally determined by GF-AAS. The linearity range of Pb(Ⅱ) was found between 1.00-40.00 μg·L-1, with detection limit (3s/k) of 0.15 μg·L-1. The proposed method was used in the determination of traces of Pb(Ⅱ) in samples of tap water and river water. Values of recovery found by standard addition method were in the range of 96.8%-105%, and values of RSDs (n=10) found were all less than 5%.