Identification of reactive dyes in spent dyebaths and wastewater by capillary electrophoresis-mass spectrometry

Capillary electrophoresis with diode array detection and mass spectrometry combined with solid-phase extraction were employed for the identification o f reactive vinylsulfone and chlorotriazine dyes and their hydrolysis produc ts in spent dyebaths and raw and treated wastewater. Recoveries of dyes fro m treated wastewater as their tetrabutylammonium ion-pairs using C-18 rever sed-phase cartridges ranged from 81 to 121%. Detection limits in sewage eff luent of the different dyes and hydrolysis products ranged from 23 to 42 mu g/l. The method was successfully applied to the detection of the hydrolysi s products of five reactive dyes in influents and effluents of a municipal wastewater treatment plant receiving dyehouse effluents. (C) 2000 Elsevier Science B.V. All rights reserved.