Analysis of contaminant polycyclic aromatic hydrocarbons in tea products and crude drugs

[摘要] Tea products and crude drugs were analyzed to determine levels of contamination with 15 polycyclic aromatic hydrocarbons (PAHs) using a new online automated method, consisting of in-tube solid-phase microextraction (SPME) coupled with high-performance liquid chromatography-fluorescence detection (HPLC-FLD). PAHs were separated within 15 min by HPLC using a Zorbax Eclipse PAH column with a water/acetonitrile gradient elution program as the mobile phase. The optimum in-tube SPME conditions were 20 draw/eject cycles of 40 µL of sample using a CP-Sil 19CB capillary column as an extraction device. Low- and high-molecular weight PAHs were extracted effectively onto the capillary coating from 5% and 30% methanol solutions, respectively. The extracted PAHs were readily desorbed from the capillary by passage of the mobile phase. Good linearity of the calibration curve (r > 0.9972) was obtained in the concentration range of 0.05–2.0 ng mL−1, and the detection limits (S/N = 3) of PAHs were 0.32–4.63 pg mL−1. Using the in-tube SPME/HPLC-FLD method, PAHs were detected at ng g−1 levels in the samples without interference peaks. Our results suggest that PAHs contamination in herbal products is widespread, and the proposed method may become a useful tool for monitoring PAH contamination and quality control in herbal products...

[学科分类] 分析化学