Determination of cadmium by differential pulse adsorptive stripping voltammetry

A study of the adsorptive stripping voltammetry of cadmium on a mercury drop electrode is reported in which 2-mercapto-5-phenil-ammino-1,3,4-thiadiazole (MPATD), synthesized at home has been used as a chelating agent. The most suitable operating conditions and parameters such as buffer, pH, deposition potential, deposition time, ligand concentration, scan rate and others were selected and the determination of cadmium from aqueous solutions using the standard additions method was possible. As validation criteria, the linearity and range, repeatability of the signal, repeatability of the concentration and accuracy were investigated. A limit of detection of 4.67 x 10(-10) M and a limit of quantification of 1.55 x 10(-9) M were achieved. The interference of other metals and organic substances was studied. Concerning a possible catalytic effect, no one was found. The method was designed in order to determine Cd from biological samples. (C) 2000 Elsevier Science B.V. All rights reserved.