Electrochemical analysis of D-penicillamine using a carbon paste electrode modified with ferrocene carboxylic acid

The electrochemical behavior Of D-penicillamine (D-PA) studied at the surface of ferrocene carboxylic acid modified carbon paste electrode (FCAMCPE) in aqueous media using cyclic voltammetry and double step potential chronoamperometry. It has been found that under optimum condition (pH 7.00), the oxidation Of D-PA at surface of such an electrode is occurred about 420 mV less positive than that an unmodified carbon paste electrode (CPE). The catalytic oxidation peak current was linearly dependent on the D-PA concentration and a linear calibration curve was obtained in the ranges 7.5 x 10(-5) M-1.0 x 10(-3) M and 6.5 x 10(-1) M-1.0 x 10(-4) M of D-PA with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods respectively. The detection limits (3 sigma) were determined as 6.04 x 10(-5) M and 6.15 x 10(-6) M. This method was also used for the determination of D-PA in pharmaceutical preparation (capsules) by standard addition method.