DIRECT-CURRENT AND DIFFERENTIAL PULSE POLAROGRAPHY OF PENICILLAMINE

The direct current and differential pulse polarographic behavior of the sulfhydryl group of penicillamine in 0.056 M citrate buffer of pH 6.45 was investigated. Depending on the concentration of penicillamine, one, two, or three waves were obtained. In most of the concentration regions investigated (1×10-5-1×10-3 M), a linear relationship was found to exist between concentration and the d.c. wave height. In the case of d.p. polarography, a linear relationship was obtained below the 5×10-4 M level. A study of the effects of mercury pressure on d.c. wave heights, the effects of Triton X-100 on both d.c. and d.p. polarograms, and the analysis of electrocapillary curves indicates that penicillamine exhibits an adsorption wave. Log plot analysis indicates that the electrode reaction product is RSHg. The calculated d.p. peak current was found to be lower than the experimental current, and the diffusion coefficient of penicillamine in 0.056 M citrate buffer of pH 6.45 was found to be 7.8×10-6 cm2 s-1. © 1979 Elsevier Sequoia S.A.