Determination of cadmium by cathodic stripping voltammetry in the presence of 4-phenylthiosemicarbazide

The electrochemical behavior of cadmium(II) is studied in the presence of 4-phenylthiosemicarbazide (4-PhTSC). It is found that the introduction of the phenyl radical into the thiosemicarbazide molecule enhances the sensitivity of cadmium determination by an order of magnitude and decreases the determination limit for cadmium(II) to 4 x 10(-9) M. The reagent is used to determine cadmium(II) in the surface water of the Prut River. The accuracy of the results is verified using standard solutions and concurrent determinations by AAS with atomization in a graphite furnace.