Analysis of polar hydrophilic aromatic sulfonates in waste water treatmentplants by CE/MS and LC/MS

The present work describes the development and optimization of a capillary (zone) electrophoresis/mass spectrometric (CE/MS) analysis method for polar hydrophilic aromatic sulfonates (ASs), The compounds were detected by nega tive ion electrospray ionization (NIESI) and selected ion monitoring (SIM), In comparison with CE/UV, for CE/MS a lower-concentration volatile ammoniu m acetate buffer (5 mM) without organic modifier and a higher separation vo ltage were better suited for separation. Sensitivity of CE/MS was slightly better than for CE/UV, with the limit of detection (LOD:) ranging between 0 .1 and 0.4 mg l(-1). For verification of the CE/MS results, ASs were also a nalysed by ion-pair liquid chromatography/diode array UV detection coupled in series with electrospray mass spectrometry (IPC/DAD/ESI-MS). Real water samples of different waste water treatment plants (WWTPs) in Catalonia (NE Spain) were extracted by solid-phase extraction (SPE) with LiChrolut EN and analysed with CE/MS and LC/MS, ASs were found in influent and effluent wat er samples of the WWTPs in the mug l(-1) concentration range. LC/MS offered a higher separation efficiency and sensitivity than CE/MS, Therefore with LC/MS more compounds could be identified in the WWTPs, The persistency of t he ASs was distinct: some compounds were well degraded during the water tre atment process, while others were quite persistent. Copyright (C) 2000 John Wiley & Sons, Ltd.