title: Determination of alkylbenzenesulfonates in recent sediments by gas chromatography/mass spectrometry.
abstract: Alkylbenzenesulfonates together with soap are the most widely used anionic surfactants. Linear alkylbenzenesulfonates (LAS) were introduced in the mid-1960s as substitutes for the poorly biodegradable tetrapropylenebenzenesulfonates (TPS). A method is presented for the selective and quantitative determination of LAS and TPS in recent sediments. Alkylbenzenesulfonates were extracted from sediments using methanol. The methanolic extract was passed through a strong anionic exchange column. The alkylbenzenesulfonates contained in the acidic eluate were then derivatized to their corresponding trifluoroethyl esters and quantitatively determined by gas chromatography/mass spectrometry using positive chemical ionization. Limits of quantitation for 10 g sediment samples varied between 1.5 and 21 μg/kg of dry sediment for single LAS isomers and between 71 and 220 μg/kg for total LAS. Limits of quantitation for the total of TPS were at ∼200 μg/kg. Relative standard deviations of replicate analyses typically ranged from 5 to 10%. Recovery rates of LAS in spiked sediment samples ranged from 79 to 113%. The presented method was applied to surface and subsurface sediments also containing long-chain (C(14)-C(16))-LAS and mixtures of LAS and TPS.
authors.affiliation: Swiss Federal Institute for Environmental Science and Technology (EAWAG) and Swiss Federal Institute of Technology Zurich, CH-8600 Düberdorf, Switzerland, and Helsinki University of Technology, Helsinki, Finland.
authors.forename: R
authors.initials: R
authors.lastname: Reiser
authors.forename: H O
authors.initials: HO
authors.lastname: Toljander
authors.forename: W
authors.initials: W
authors.lastname: Giger