HG-AFS Determination of Trace Amount of Lead in Water Samples with Enrichment by Cloud Point Extraction

A method for determination of trace amount of lead in water by HG-AFS was proposed in this paper. Trace amount of Pb was extracted from the sample solution in the from of coordination complex with dithizone in sodium borate solution of pH 8.0 by cloud point extraction with Triton X-114 as non-ionic surfactant. A solution of 15.0 g·L-1 KBH4 was used as reductant for generation of PbH4 in a medium of HCl (1+99). Linear relationship between values of fluorescence intensity and mass concentration of Pb was obtained in the range of 0.05-3.2 μg·L-1 with detection limit (3S/N) of 0.016 μg·L-1. The proposed method was applied to the determination of Pb in water samples, giving values of recovery ranged from 96.5% to 104.6% and RSD′s (n=6) less than 5%.