DETERMINATION OF LINEAR ALKYLBENZENESULFONATES AND THEIR DEGRADATION PRODUCTS IN WATER SAMPLES BY GAS-CHROMATOGRAPHY WITH ION-TRAP MASS-SPECTROMETRY

A method was developed for the analysis of Linear alkylbenzenesulfonat es (LAS) and their degradation products, sulfophenylcarboxylic acids ( SPC), in samples of sewage effluent and river water. This method invol ved extraction of the samples by graphitized carbon black cartridge, e sterification by a two-step thionyl chloride-trifluoroethanol derivati zation procedure, and separation, identification and quantitation by i on-trap CC-MS with EI and low pressure CT modes. High selectivity with few signals was observed in the low pressure CI mass spectra of LAS a nd SPC. Enhanced sensitivity with protonated molecular ion chromatogra ms of homologous C-10-C-13 LAS by CT-MS permit the determination of LA S and SPC at trace concentrations in environmental samples. Recovery r ates of LAS and SPC in spiked water samples ranged from 75 to 112% wit h R.S.D, values from 3 to 26%. The limit of quantitation for both LAS and SPC was estimated to be 0.01 mu g/l in 100 ml of water sample. (C) 1998 Elsevier Science B.V. All rights reserved.