Determination of polycyclic aromatic hydrocarbons in river water by HPLC after stir bar sorptive extraction

The sample preparation technique of stir bar sorptive extraction (SBSE) was used for the determination of polycyclic aromatic hydrocarbons (PAHs) in river water samples. The 100 ml river water sample and 10 ml of methanol were placed in a 125 ml vial. A stir bar coated with 126 mu l of polydimethylsiloxane was added to the sample, and the extraction was performed at 800 rpm for 3 hr. After the extraction, the stir bar was placed into a 250 mu l insert of a 2 ml vial filled with 200 mu l of acetonitrile. Liquid desorption was performed with sonication for 15 min. The extract solution was analyzed by high-performance liquid chromatography with a fluorescence detector (HPLC-FL). Once SBSE was optimized, validation methods such as linearity (r > 0.999), detection limits (0.6 similar to 6.0 pg/ml) and quantitation limits (2.0 similar to 20 pg/ml) were performed. The average recoveries of PAHs were higher than 94.8% (RSD: 1.9 similar to 8.6%). This simple, accurate, sensitive and selective analytical method may be used in the determination of trace amounts of PAHs in river water samples.