Determination of 16 Polycyclic Aromatic Hydrocarbons in Dry Prophyra by Gas Chromatography-Mass Spectrometry with Dispersive Solid Phase Extraction

The sample (2.00 g) of the dry prophyra was placed into a 50 mL centrifuge tube, and 1.00 mg·L^-1 mixed solution (100 μL) of internal standards and 4 mL of water were added to wet the sample. And then 10 mL of n-hexane was added into the solution to homogenize for 20 s, and 4.0 g of anhydrous magnesium sulfate and 1.0 g of sodium chloride were added into the solution and the mixture was vortexed for 2 min. After centrifugation, 100 mg of N-propylethylenediamine (PSA) and 100 mg of anhydrous magnesium sulfate were added into 1 mL of the supernatant and the mixture was vortexed for 1 min. After centrifugation, 16 PHAs in the superanatant were determined by gas chromatography-mass spectrometry (GC-MS). Linear relationships between the ratio of the peak area of 16 PAHs to that of the internal standard and mass concentration of PAHs were obtained in definite ranges, with detection limits (3S/N) of 0.57-3.8 μg·kg^-1. Test for recovery was made by standard addition method, giving results in the range of 78.3%-109%, and values of RSDs (n=6) were in the range of 1.2%-14%.