Analysis of dyestuff degradation products by capillary electrophoresis

Capillary electrophoresis (CE) with two different detection methods, mass spectrometry (MS) and UV absorption spectroscopy with photodiode array detection (UV/DAD), was used for the analysis of the degradation products of dyestuffs. We have studied wet oxidation with solid catalyst as the treatment method of wastewaters containing dyestuffs. When the Orange II (C.I. Acid Orange 7) solution was used as the model wastewater, treated solution contained unknown highly polar degradation products. We were able to determine the molecular masses of some products by CE-MS. From this clue, we tried to identify these products by CE-UV/DAD. By means of the comparison of the migration time and UV spectra of standard samples, three degradation products were identified. The separation of degradation products was successful within 15 min.