Sensitive Determination of Polycyclic Aromatic Hydrocarbons in Water by Online Solid Phase Extraction Coupled with High Performance Liquid Chromatography / 分析化学

ABSTRACT

A method was developed for the determination of polycyclic aromatic hydrocarbons ( PAHs ) in water by HPLC coupled with online solid phase extraction ( online SPE ) . After filtered, 1 mL of a water sample was injected directly, and then trapped on the SPE column ( Acclaim PAⅡ, 50 mm × 4. 6 mm, 3 μm) for extraction and purification; finally, the trapped analytes were transferred to the analytical column (Hypersil Green PAH, 150 mm × 3 mm, 3 μm) for the separation using valve-switching technique. The mobile phase used for online SPE was water/acetonitrile at different flow rate ( 0 . 4 and 0 . 6 mL/min ) in gradient elution mode;and that used for the separation was water/acetonitrile at 0. 8 mL/min flow rate. UV wavelength was set at 254 nm for the determination of naphthalene and acenaphthylene with no/very weak fluorescent response;fluorescence detection using programmed wavelength switching in three parallel channels was used for the other PAHs. The whole analysis process including online SPE and separation was completed within 32 min. The relative standard deviation ( RSD) of 20 PAHs were all less than 0. 16% for retention time, and less than 1. 3% for peak area (n=7). The peak area had a good linearity with the sample concentration in three orders of magnitude with correlation coefficients of above 0 . 9910 . The recoveries for 0 . 05 μg/L of each analyte in tap water were in the range of 57%-140%, and for 5 . 0 μg/L of each analyte were in the range of 85%-116%. The limits of detection of the method were less than 0 . 05 μg/L ( S/N=3 ) for most PAHs.