提出了氢化物发生-原子荧光光谱法测定水中痕量铅的方法。以双硫腙为络合剂,在pH 8.0的硼砂溶液中,用非离子表面活性剂Triton X-114浊点萃取样品溶液中痕量铅。选用15.0 g·L-1硼氢化钾溶液作为产生氢化铅的还原剂,氢化物发生反应在盐酸(1+99)介质中进行,铅的质量浓度在0.05~3.2 μg·L-1范围内与其相应的荧光强度呈线性关系。方法的检出限(3S/N)为0.016 μg·L-1。应用此方法测定了水中铅的含量,测得回收率在96.5%~104.6%之间,相对标准偏差(n=6)均小于5%。

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%.