A rapid detection method of 16 preservative residues in vegetables for export was developed by gas chromatography_mass spectrometry ( GC_MS ) after pre_treatment method of dispersive solid phase extraction ( SPE) . Samples including leafy, eggplant fruit, bean, melon and tuber vegetables were extracted with acetonitrile and detected by GC/MS with external standard method after being cleaned up with dispersive SPE. The results showed that the method had a good linearity over concentration range of 0 . 02-2 . 0 mg/L preservatives with correlation coefficients of 0 . 9990-0 . 9997 . The limits of detection ( LODs ) were in the range of 0. 004-0. 965 μg/kg. The recoveries of the preservatives were in the range of 76. 7%-120. 0% at the spiked levels of 0. 01, 0. 02 and 1. 00 mg/kg, and the relative standard deviations ( RSDs) were in the range of 2. 1%-10. 6%. Compared with the GB/T 19648_2006, etc, the method is rapid, simple, highly sensitive, and can meet testing requirements of 16 preservative residues in vegetables for export.

A high performance liquid chromatography-tandem mass spectrometric ( HPLC-MS / MS) method coupled with an immunoaffinity clean-up column was successfully developed for determination of aflatoxins (AFB1 , AFB2 , AFG1 , AFG2 , AFM1 and AFM2 ) and zeranols ( α-zeranol, β-zeranol, α-zearalenol,β-zearalenol, zearalanone and zearalenone ). The sample was extracted with methanol-acetonitrile (20∶ 80, V/ V) after enzymatic digestion by β-glucuronidase / sulfatase, and the extraction solution was passed through glassy fiber filter paper and then diluted with phosphate buffer solution (PBS). The reconstituted solution was cleaned up with IAC-AZ immunoaffinity column, and then analyzed by HPLC-MS / MS in multiple reaction monitoring (MRM) mode. The results indicated that the linear detection range was 0. 03-6. 0 μg / L for AFB2 and AFG2 , and 0. 05-20 μg / L for the rest compounds. The correlation coefficients were above 0. 999. The limits of detection (LOD) and limits of quantitation (LOQ) were 0. 01-0. 03 μg / kg and 0. 04-0. 09 μg / kg, respectively. The recoveries of the aflatoxins and zeranols were in the range of 73. 6% -98. 4% at the spiked levels of 0. 5, 1 and 5 μg / kg, and the relative standard deviations (RSDs) were in the range of 1. 9% -11. 2% . The method was proved to be simple and accurate, and suitable for the rapid determination of aflatoxins and zeranols in animal-originated foods.