Résumé
A simple and sensitive extraction-spectrophotometric method for the determination of lead is described. The complex formed between lead and Dithizone is extracted with chloroform at pH 9.5, and shows maximum absorbance at 520nm with a molar absorptivity of 1.8 x 10[5] L mol[-1] cm[1]. It obeys Beer's law over the range 0.16-1ppm. Various experimental parameters were studied for establishing the optimum conditions for the determination of lead. The method had been applied to the determination of lead in marine environmental samples. A step-by-step approach has been taken, through sampling, laboratory cleanliness, pre-treatment, extraction, instrumental measurement and, finally, the now much emphasised areas of method validation, analytical quality control and proper reporting of results