Journal of Chromatography A, 889 (2000) 99–104 www.elsevier.com / locate / chroma Extraction and isolation of linear alkylbenzene sulfonates and their intermediate metabolites from various marine organisms * ´ ´ ´ ´ M. Saez, V.M. Leon, A. Gomez-Parra, E. Gonzalez-Mazo ´ ´ ´ ´ ´ Departamento de Quımica Fısica, Facultad de Ciencias del Mar, Universidad de Cadiz, Polıgono Rıo San Pedro s / n, ´ 11510 Puerto Real, Cadiz, Spain Abstract A method has been developed for the determination of linear alkylbenzene sulfonates and its degradation intermediates (sulfophenylcarboxylic acids) from different marine organisms, which includes the stages of extraction and analysis by liquid chromatography with fluorescence detection. The extraction stage (Soxhlet and solid-phase extractions) was optimised by the selection of the appropriate solvent, minicolumns and different clean-up stages. Recoveries varied in the range from 80 to 21 104%, with a standard deviation between 1 and 9%. Detection limits were 15 ng g wet mass for undecylbezene sulfonate 21 and 30 ng g wet mass for sulfophenylundecanoic acid using HPLC–fluorescence detection. The complete analytical method was successfully applied to different marine organisms from the Bay of Cadiz (SW Spain).  2000 Elsevier Science B.V. All rights reserved. Keywords: Environmental analysis; Extraction methods; Sparus aurata; Diplodus vulgaris; Ruditapes decussatus; Alkyl- benzene sulfonates, linear; Surfactants; Sulfophenylcarboxylic acids; Carboxylic acids 1. Introduction fact, the concentrations found in marine sediments are up to three orders of magnitude higher than those Synthetic surfactants are used as the principal found in water; and among these solid–liquid inter- constituents of commercial detergents. Among these, faces are the membranes of marine organisms; and linear alkylbenzene sulfonates, LAS, are the most (ii) biological tissues have a high lipid content and commonly used anionic surfactants [1]. In coastal therefore LAS (lipophilic nature) should be easily zones, the presence of LAS and their degradation dissolved in these lipids. The study of their degra- intermediates (sulfophenylcarboxylic acids, SPC), is dation products, SPC, is also important. They are now a fact [2], because most of the detergents more polar products and therefore, if the accumu- consumed are discharged via urban sewer systems lated LAS are transformed into SPC [4–6], this into the marine medium, to a large extent without degradation pathway could be a natural mechanism prior treatment of the sewage. of the organisms for purification. Studies of LAS bioconcentration are important for Published bioconcentration studies of LAS are the following principal reasons: (i) Due to their scarce [7] and were performed with radiolabelled surfactant character, LAS tend to accumulate at LAS. Since LAS are biotransformed in fish [4–6] interfaces, both liquid–gas and liquid–solid [3]; in and since biotransformation products were not sepa- rated from the intact LAS, the data available from *Corresponding author. these previous studies do not provide a quantitative 0021-9673 / 00 / $ – see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S0021-9673(00)00204-1