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 alkylbenzenesulfonate (LAS) residues from sediment samples. The analytes can be completely extracted by methanol at 100°C and 100atm with combined 15min static and 20min dynamic extraction steps. The LAS residues were then identified and quantitated by gas chromatography-mass spectrometry (GC-MS) with ion-pair derivatization in the gas chromatography (GC) injection-port using a large volume (10-20μl) direct sample introduction (DSI) device. LAS recovery from spiked kaolin 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. Copyright (C) 2000 Elsevier Science B.V.