Antimony film electrode for direct cathodic measurement of sulfasalazine

The antimony film electrode (SbFE) is presented for the first time for direct cathodic voltammetric measurement of an organic compound, i.e. sulfasalazine, which has been chosen due to its aptness for electrochemical reduction and its great importance as a pharmaceutical product. The SbFE was prepared ex situ on the surface of a glassy carbon supporting electrode and several important parameters were studied and optimized, such as preparation of the SbFE, stripping voltammetric settings, pH of the measurement solution, etc. In addition, the electroanalytical performance of the SbFE was compared to its bismuth counterpart and bare glassy carbon electrode. The SbFE exhibited excellent linear dependence in the examined concentration range of 3 × 10−6–2.5 × 10−4 M together with the detection limit of 7.8 × 10−7 M and good reproducibility with the RSD of ±0.7%. Finally, the applicability of the SbFE was successfully demonstrated through convenient measurements of sulfasalazine in its dosage forms of sulfasalazine delayed-release tablets.