Degradation of Antihypertensive Hydrochlorothiazide in Water from Pharmaceutical Formulations by Electro-Oxidation Using a BDD Anode

摘要

The electrochemical oxidation (EO) of hydrochlorothiazide (HCTZ) in water has been carried out atapplying constant current in an electrochemical cell containing a boron-doped diamond (BDD) anodeand a stainless steel cathode. The effect of initial pH of the solution and the applied current densitywere evaluated in the HCTZ concentration decay and total organic carbon abatement during theelectrolysis. A qualitative analysis of the degradation by-products was made by chromatography andphotometric assays. Finally, EO was applied for the HCTZ degradation from commercial formulations.Thus, HCTZ can be degraded by EO at neutral pH, applying low current densities due to the attack of?OH electro-generated on the BDD surface. Aromatic intermediates, aliphatic carboxylic acids, andinorganic anions were detected as main products during the mineralization of HCTZ to CO2. Solutionsprepared from commercial formulations of HCTZ were completely mineralized by EO, which can bean interesting step towards the applicability of the EO processes for the treatment of wastewatercontaining these kinds of drugs as raw materials or pharmaceutical formulations.