Sequential extraction-spectrofluorimetric determination of lead and cadmium using cryptands
Abstract
A spectrofluorimetric method for the determination of ultratrace amounts of lead and cadmium 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 a counter ion. A linear working range from the detection limit (0.5 ng ml–1) to 250 ng ml–1 of lead and to 150 ng ml–1 of cadmium was obtained. The relative standard deviation was 2–4%. The proposed method has been applied successfully to the determination of lead and cadmium in zinc metals and soft drinks.