Determination of Trace Lead in Water and Milk Tea Powder Samples with Organic Coprecipitation-Flame Atomic Absorption Spectrometric

A method was proposed for the determination of trace lead with flame atomic absorption spectrometry after preconcentration of lead by rapid coprecipitation technique with PAR-Fe(III) at pH 6.0. The analytical parameters including pH, amount of iron(III), amount of reagent, the standing time of the precipitate, etc., were examined. The detection limits (DL) were found to be 18.7 mu g . L-1 for Pb(II). In analysis of lake water and the milk tea powder samples, RSD's and the standard addition recovery of this method were in the ranges of 1.03%similar to 2.24% and 94.2%similar to 98.3% respectively. The effect of matrix can be overcome by the method and the results are satisfyiog. The method shows good application prospect in the determination of trace lead owing to its rapidness and reproducibility.