Electrochemical behavior of paclitaxel and its determination at glassy carbon electrode

The electrochemical behavior of paclitaxel drug was studied at a glassy carbon electrode in phosphate buffer solutions using cyclic and differential-pulse voltammetric techniques. The oxidation process was shown to be irreversible over the pH range (3.0–10.4) and was diffusion controlled. Effects of anodic peak potential (Ep), anodic peak current (Ipa), scan rate, pH, heterogeneous rate constant (k0), etc have been discussed. A possible electro-oxidation mechanism was proposed. An analytical method was developed for the determination of paclitaxel in phosphate buffer solution at pH = 7.0 as a supporting electrolyte. The anodic peak current varied linearly with paclitaxel concentration in the range 1.0 × 10−6 M to 1.0 × 10−5 M with a limit of detection (LOD) of 1.23 × 10−8 M and limit of quantification (LOQ) of 4.10 × 10−8 M. The proposed method was successfully applied to the determination of paclitaxel in pure and real samples.