Boron-doped diamond electrodes: examining the effect of doping level on the degradation of pharmaceuticals

The effect of the boron content doped in the diamond electrode on the oxidative degradation behaviour of the active pharmaceutical ingredient abacavir was investigated. The characteristics of five working boron-doped diamond electrodes, differing in a B/C doping ratio of 500 ppm, 1000 ppm, 2000 ppm, 4000 ppm, and 8000 ppm, were studied. The oxidative degradation of the substance abacavir was studied in a batch cell. The degradation took place under potentiostatic electrolysis at potentials from +0.6 V to +3.7 V. The boron level has a significant effect on the oxidative degradation of the substance at potentials greater than +2.0 V only. Liquid chromatography coupled with mass spectrometry was employed to verify the generation of two primary degradation by-products, namely OP1 (m/z = 319.20) and OP2 (m/z = 247.19). The relative amounts of these degradation products showed variability depending on the diamond electrode used, which was conditioned by different B/C ratios.