GF-AAS Determination of Traces of Lead in Water Sample after Enrichment by DLLME

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%.