Characterization and Determination of Linear Alkylbenzenesulfonates in Environmental Water Samples by High-Performance Liquid Chromatography with a Hydrophilic Polymer Column and Electrospray Ionization Mass Spectrometric Detection

A liquid chromatography-mass spectrometry (LC/MS) method was developed for the separation and determination of linear alkylbenzenesulfonates (C10 - C14 LAS) in environmental water samples using a hydrophilic polymer column (Shodex Mspak GF-310 4D). This method involves a solid-phase extraction of the LAS samples with a Sep-Pak PS-2 cartridge. The LAS components were separated on the column with a mobile phase of 29% (w/v) acetonitrile-water containing 0.8 mM di-n-butylammonium acetate and 0.2 M acetic acid, and were detected by mass spectrometry with electrospray ionization. Detection limits of the developed method based on selected ion monitoring (SIM) technique for the C10 - C14 LAS standards were 13 - 47 ng L-1. The concentrations of the C10 - C14 LAS in the environmental water samples ranged between 5 - 317 μg L-1 for a river water sample and 0.4 - 6.4 μg L-1 for a seawater sample. Linear relationships between the logarithms of retention factors and the alkyl chain lengths for each phenyl positional isomer of LAS could successfully be used for the identification of the isomer peaks.