Simultaneous Determination of 16 Polycyclic Aromatic Hydrocarbons in Textiles and Plastic Food Packages by Ultrasonic Extraction-Affinity Capillary Electrophoresis-Laser Induced Fluorescence Method

By optimizing the acidity of background electrolyte and the concentrations of borax, carboxymethyl groups-β-cyclodextrin(CM- β- CD) as well as dimethyl-β-cyclodextrin (DM-β-CD) for background electrolyte, the title method was proposed utilizing differences of the affinity between polycyclic aromatic hydrocarbons (PAHs) and CM-β-CD as well as PAHs and DM-β- CD. Refer to GB/T 28189—2011 for sample pretreatment, the sample was cut into the thin strip with 0.5 cm×0.2 cm. An aliquot (1 g) of the sample was taken, and 50 mL of cyclohexane was added. The mixture was sealed, and extracted by ultrasound at 50 ℃ for 1 h. After cooling to room temperature and filtering, the filtrate was analyzed by high performance capillary electrophoresis instrument with laser induced fluorescence detector at fluorescence detection wavelength of 325 nm, and the mixed solution containing 30 mmol·L^-1 CM-β-CD, 20 mmol·L^-1 DM-β-CD and 40 mmol·L^-1 borax was used as the background electrolyte (pH 5.0). It was shown that mass concentrations of 16 PAHs showed linear relationships with peak areas in the range of 0.01-0.5 mg·L^-1, with detection limits in the range of 0.002-0.040 mg·L^-1. Test for recovery was conducted using the standard addition method, giving results in the range of 91.4%-104%, and RSDs (n=5) of the determined values ranged from 0.40% to 6.3%. The proposed method was applied to the analysis of 3 textiles and 5 plastic food packages, and PAHs were detected to varying degrees in 8 samples.