Study On The Analysis Method Of Residue Of Veterinary Medicine And Persistent Organic Pollution

The extraction and clean-up method of Corticosteroids and Dioxin like polychlorinated biphenyls in animal food was studied; Parameters of ion preparation mode were developed for the determination of two Corticosteroids as example and 12 dioxin like polycholorinated biphenyls in food samples using ion trap tandem mass(IT-MS/MS, Finnigan Polaris Q); Operating conditions of ion trap tandem mass spectrometry were optimized and comparison between results obtained by IT-MS/MS with high resolution mass spectrometry (HRMS) was pursued.Solid phase extraction ( SPE) and GC-ion- trap MS/MS method has been developed for the determination of prednisolone and methylprednisolone residues in tissue. The conditions for extraction, clean-up on C18 column and oxidization with K₂Cr₂O₇ of prednisolone and methylprednisolone were investigated. The voltages for Collision-induced dissociation of prednisolone and methylprednisolone were 1.0 v and 1.25 v severally. Linear calibration curves were obtained in the concentration ranges from 2 to 50μg/Kg for prednisolone and methylprednisolone ( the correlation coefficients were above 0.99). The average recoveries for prednisolone and methylprednisolone spiked in tissue of pork ranged from 56 to 84% and their relative standard oxide were between 9.2% and 18.1%. The limits of detection (LOD) and the limits of quantification (LOQ) of the method were 1μg/Kg and 2μg/Kg for the two drugs.. Analytical procedure of dioxin like polychlorinated biphenyls (DL-PCBs) residue in milk consisted of ASE extraction, lipid removal with acid silica and clean-up using anthropogenic isolation column packed with multilayer silica. The analytes were separated by DB-5 chromatographic column, detected with multiple reaction monitor mode ( EI-MRM) and quantified using internal standard calibration curve of isotope dilution technique. The correlation coefficients of calibration standard solution were above 0.9999 for all the DL-PCBs. The recoveries and RSDs of labeled compound solution were obtained from 39 to 129% and from 5 to 22% respectively. Method detection limits ranged from 3 to 11 pg/g (fat) were established for the 12 DL-PCBs.Operating conditions of ion trap tandem mass spectrometry were optimized and comparison between results obtained by IT-MS/MS with high resolution mass spectrometry (HRMS) was pursued. Dioxin like PCBs were extracted from samples by accelerated solvent extraction (ASE) and purified by fluid management systems (FMS) before quantitative analysis with IT-MS/MS and HRMS respectively. The regression lines and regression coefficients of the results for target PCBs acquired by the two techniques are showed as follows: 4 non-ortho-CBs, y=0.7815x , r²=0.8707; 8 ortho-CBs, y=0.8073x,r²=0.992; total TEQ of all the target PCBs, y=0.5181x+0.1255,r2= 0.984. The method detection limits established for IT-MS/MS was 0.5 ng/Kg while HRMS was 0.1 ng/Kg.