Determination of PCBs in tobacco by GC/MS

In order to control exogenous contamination risks for raw materials used in oral tobacco products, a qualitative and quantitative analysis method for polychlorinated biphenyls(PCBs)in tobacco leaves was established. The developed method for the simultaneous determination of seven PCBs in tobacco by gas chromatography-mass spectrometry(GC-MS)was applied to test 42 domestic and imported tobacco samples. After extraction, vacuum concentration to drying, re-dissolving and purification, the tobacco powder samples were quantified by gas chromatography-mass spectrometry(GC-MS) with internal standards. The results showed that:1) The linearity of curves of the seven PCBs'concentration-response relationship was good with the correlation coefficient range between 0.984 3-0.994 8. 2) The limit of detection and the limit of quantification were 0.22-1.07 and 0.73-3.57 ng·mL^-1, respectively. The spiked recovery ranged from 70.4% to 95.5% with the intra-day and inter-day relative standard deviations no more than 4.6% and 9.2%, respectively. 3) Different amounts of the seven PCBs were detected in the 42 samples with the maximum total amount of 0.37 mg·kg^-1, which was lower than the limit level of PCBs in food(≤ 0.5 mg·kg^-1 in total). This method is simple, rapid and suitable for the detection of PCBs in tobacco samples.