Application of semidifferential electroanalysis to anodic stripping voltammetry

• Published in: Analytica chimica acta 1978-10, Vol.101 (1), p.131-138
• Main Authors: Goto, Masashi, Ikenoya, Kazuhiko, Kajihara, Masaya, Ishii, Daido
• Format: Article
• Language: English
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(01)83847-2

A new voltammetric technique, Semidifferential electroanalysis, in which the semiderivative, e, of the current, i, is measured as a function of electrode potential, has been applied for detection in anodic stripping voltammetry. The semiderivative of the current is defined by [fx131-1.tif] Cd 2+, Pb 2+, and Tl + in 0.1 M KNO 3 at different pH values were tested as samples on a hanging mercury drop working electrode. Symmetrical sharp peaks were observed for the re-dissolution processes of metal amalgams formed during pre-electrolysis at -1.0 V vs. SCE. The peak potentials of e vs. E curves for the above three amalgams agreed well with the literature values for d.c. polarographic half-wave potentials. The peak heights were proportional to the pre-electrolysis time up to about 5 min, to the potential scan rate in the range 60–160 mV s -1, and to the concentrations of Cd 2+, Pb 2+, and Tl + in the original solution in the range 10 -6–10 -9 M. The relative standard deviation for the determination of Cd 2+ was about ±4% at the 2 × 10 -5 M level.