Determination of linear alkylbenzenesulphonates, alkylphenol polyethoxylates and nonylphenol in waste water by high-performance liquid chromatography after enrichment on octadecylsilica.

An enrichment procedure involving percolation through octadecylsilica cartridges was applied to the extraction of linear alkylbenzenesulphonates (LASs), alkylphenol polyethoxylates (APEOs) and nonylphenol (NP) from treated and untreated municipal waste waters. The analytes were quantitated by reversed-phase high-performance liquid chromatography with UV-fluorescence detection. Recoveries higher than 80% were obtained from the analysis of biologically treated waste waters. The method allows rapid, precise and reliable determination of LASs and APEOs at concentrations as low as 20 and 4 micrograms l-1, respectively.