Cloud point extraction and flame atomic absorption spectrometry determination fo trace lead in urine

A method for the determination of Pb in urine by flame atomic absorption spectrometry with cloud point extraction was established. Dithizone-acetone was selected as the complex reagent and TritonX-100 as the surfactant. Effects of pH concentrations of surfactant and complex reagent equilibrium temperature and time on the efficiency and sensitivity for clound point extraction were investigated. Under optimal conditions the detection limit was 0. 06 μg·L-1( n=11) with linear over the concentration range of 0 ~ 1. 00 μg·mL-1,and values of recovery were in the range of 96. 7% ~101%. The present method was applied to the determination of trace lead in urine samples with satisfactory results.