Specific determination of linear Alkylbenzenesulfonates (LAS) in commercial detergents and whole blood by high-performance liquid chromatography with solid-phase extraction.

This paper presents the extraction and analysis of linear alkylbenzenesulfonates (LAS) from whole blood using solid-phase extraction (SPE) together with high-performance liquid chromatography (HPLC). The sample was buffered with extraction solution and purified with Bakerbond C(18) SPE columns. The columns were washed, dried, and eluted with experimental optimized solvent systems. HPLC was performed using a Wakopak) WS AS-Aqua column (4.6 * 250-mm) and monitored at 228 nm using a UV detector. A mobile phase consisting of acetonitrile/water (60:40, v/v) and containing 1.2% (w/v) of sodium perchlorate was employed. Good separation was achieved for the five homologues of LAS (C(10) approximately C(14)) eluted at 6.85 and 13.79 min. The linearity range for this analysis was found to be from 10.0 to 100.0 ng/g and the limit of detection was 4.0-5.0 ng/g in blood for each homologue. The recovery of each homologue in blood ranged from 76 to 107%. The LAS in commercial detergents could be extracted and the homologues of C(10) approximately C(13) were detected. Blood samples of rats, which were administered a commercial detergent orally, were determined by the present method, and C(14) was used as an internal standard. The method was simple and reliable for the determination of LAS in blood samples and could be expected to apply to the forensic and clinical specimens.