Application of a polysiloxane-based extraction method combined with column liquid chromatography to determine polycyclic aromatic hydrocarbons in environmental samples

Silicone rods with a diameter of 1 mm and 10 mm long were used to extract polycyclic aromatic hydrocarbons (PAHs) from water samples and for the rapid screening of highly contaminated waste material. The rods were placed in a 15 ml glass vial for the extraction of the analytes, which involved shaking (300 min^-1) the sample for 3 h. After extraction the rods were placed into 250 (mu)l inserts of 2 ml vials filled with 100 (mu)l of an acetonitrile–water mixture (4:1) and desorption was performed with sonication for 10 min. Then the PAHs were determined using LC and fluorescence detection. Recoveries of the rod extraction ranged between 62 and 97% and the detection limits were between 0.1 and 1.2 ng l^-1. These results are comparable with those of stir bar sorptive extraction (SBSE). Although the rods are reusable, their low price means they can be discarded if contaminated, eliminating the need for expensive cleaning. One disadvantage compared to SBSE is the longer extraction time needed to reach equilibrium.