Determination of cadmium by differential pulse adsorptive stripping voltammetry

A study of the adsorptive stripping voltammetry of cadmium on a mercury dro p electrode is reported in which 2-mercapto-5-phenil-ammino-1,3,4-thiadiazo le (MPATD), synthesized at home has been used as a chelating agent. The mos t suitable operating conditions and parameters such as buffer, pH, depositi on potential, deposition time, ligand concentration, scan rate and others w ere selected and the determination of cadmium from aqueous solutions using the standard additions method was possible. As validation criteria, the lin earity and range, repeatability of the signal, repeatability of the concent ration and accuracy were investigated. A limit of detection of 4.67 x 10(-1 0) M and a limit of quantification of 1.55 x 10(-9) M were achieved. The in terference of other metals and organic substances was studied. Concerning a possible catalytic effect, no one was found. The method was designed in or der to determine Cd from biological samples. (C) 2000 Elsevier Science B.V. All rights reserved.