Objective To develop a method for the simultaneous determination of 18 kinds of polychlorinated biphenyls (PCBs) in pork by isotope dilution-gas chromatography-high resolution magnetic mass spectrometry. Methods The optimal conditions of the accelerated solvent extractor and fully automated clean-up apparatus were determined by optimizing the extraction rate of the target substances using an accelerated solvent extractor and a fully automated clean-up instrument combined with isotope dilution method coupled with gas chromatography-high resolution magnetic mass spectrometry. A 4-factor, 3-level orthogonal test was designed using the extraction temperature, static extraction time and the number of cycles as the main factors to investigate the effect of the accelerated solvent extractor on the extraction rate of the fat content of the samples. The effects of the accelerated solvent extractor on the extraction rate of fat content of the samples were investigated. Results The linear relationships of the indicator PCBs (PCB28, PCBB52, PCB101, PCB118, PCB138, PCB153, PCB180) was good in the range of 0.5 to 200.0 pg/µL, and the linear range of the DL-PCBs (PCB77, PCB81, PCB105, PCB114, PCB123, PCB126, PCB156, PCB157, PCB167, PCB169, PCB189) had a good linear relationship in the range of 0.10 to 40.0 pg/µL, the correlation coefficients were all above 0.999. The limits of detection were in the range of 0.001-0.004 pg/g, and the limits of quantitation were in the range of 0.004-0.012 pg/g; the accuracy and precision of the fishmeal matrix standard reference material were tested by this study, and the PCBs levels were within the range with the relative standard deviations of 1.0%-7.5%. For the determination of actual samples of pork, and the contamination levels of PCBs in 18 kinds of were 1978.9-2530.8 pg/g fat. Conclusion This study is efficient, accurate, sensitive and suitable for the determination of 18 kinds of PCBs in pork.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |