Capillary electrophoresis applied to kinetic studies of photocatalytic oxidation of substituted anilines

Cyclodextrin modified capillary electrophoresis (CMCE) and micellar electrokinetic chromatography (MEKC) were tested for their ability to analyze mixtures containing substituted anilines. CMCE separated analytes by their partitioning preference between the two substituted cyclodextrins while MEKC exploited the analyte partitioning between the micelles and the bulk aqueous phase. MEKC was selected to analyze samples that were subjected to photocatalytic oxidation using TiO₂ and/or SnO₂ as the semiconductor catalyst. The rate constant for each compound was determined when it was degraded individually or in the presence of other derivatives in the same family, indicating a significant degree of analyte competition and synergism offered by the mixed catalyst. The results demonstrated that CE, with its minimal sample preparation and requirement, is a valuable tool, particularly suitable for studying highly toxic pollutants, without generating a high volume of waste.