SEQUENTIAL EXTRACTION SPECTROFLUOROMETRIC DETERMINATION OF LEAD AND MERCURY USING CRYPTAND ETHERS

A spectrofluorimetric method for the determination of ultratrace amoun ts of lead and mercury is described based on the sequential extraction of the ternary ion-association complexes formed between the cation, a cryptand as the ligand and eosin as counter ion. A linear working ran ge from the detection limit (9 ng/ml) to 250 ng/ml of lead and 120 ng/ ml of mercury was obtained. The relative standard deviation was 3.5 % - 2.1 %. We propose that this method could be used routinely to contro l lead and mercury simultaneous.