[Reversed-phase high performance liquid chromatographic separation of linear alkylbenzenesulfonate homologues and positional isomers].

A reversed-phase high performance liquid chromatographic method has been developed. It is relatively simple and effective for the determination of linear alkylbenzenesulfonates (LAS). The effects of methanol content, electrolyte concentration and the type of electrolytes in mobile phase on the retention of LAS, selectivity, efficiency, and resolution are discussed. The optimal chromatographic conditions used were a reversed-phase C18 column with detection wavelength at 226 nm and methanol-30 mmol/L sodium dihydrogen phosphate aqueous solution as mobile phase for gradient elution. A complete separation of the homologues has been obtained and the positional isomers were partially resolved.