Determination of linear alkylbenzenesulfonates in sediments using pressurized liquid extraction and ion-pair derivatization gas chromatography-mass spectrometry

A time and solvent saving method, called pressurized Liquid extraction (PLE ), was developed to extract linear alkylbenzene-sulfonate (LAS) residues fr om sediment samples. The analytes can be completely extracted by methanol a t 100 degrees C and 100 atm with combined 15 min static and 20 min dynamic extraction steps. The LAS residues were then identified and quantitated by gas chromatography-mass spectrometry (GC-MS) with ion-pair derivatization i n the gas chromatography (GC) injection-port using a large volume (10-20 mu l) direct sample introduction (DSI) device. LAS recovery from spiked kaoli n samples was 115% with 4% RSD. For lake sediment samples, LAS recovery was 110% with 2% RSD. The PLE method was also tested with recently spiked and aged samples showing its perfect applicability for LAS extraction. (C) 2000 Elsevier Science B.V. All rights reserved.