Performance Liquid Chromatography - Mass Spectrometry Detected Aquatic Veterinary Drug Residue Studies

In this study, applying High Performance Liquid Chromatography tandem Mass Spectrometry, a method of purifying and enriching the detected residues was built by optimizing fore treatments including solid phase extraction, liquid phase extraction, derivatization and so on. The method in the level of trace amount was presented to simultaneously detect avermectins, chloramphenicol and the metabolites of nitrofuran antibiotics by optimizing suitable chromatography condition including chromatographic column, mobile phase and mass spectrogram. By the comparation of pre-treatments, chromatography and mass spectrogram, the consequence and discussion were made from the results and mechanisms, so the method in the level of trace amount was built to analyse the residues of avermectins, chloramphenicol and metabolites of nitrofuran antibiotics.First, simultaneously detecting the residues of abamectin and ivermectin and eprinomectin and doranectin abamectin in catfish, eel and fresh crayfish by high performance liquid chromatography tandem mass spectrometry. Electing acetonitrile to distill the residues after comparing the distilling rate of different organic solvent, and optimizing suitable chromatography condition including chromatographic column, mobile phase and mass spectrogram by ESI. With appending three different levels in catfish, eel and fresh crayfish, the recoveries were in the range of 70.8—84.4%, the CV was not more than 17%, LOQ was 1.0—2.0μg/kg and LOD was 0.3—0.5μg/kg.Secondly,when detecting chloramphenicol in crayfish and zoogenic tissue by High Performance Liquid Chromatography tandem Mass Spectrometry,we found that crayfish and other enriching oleaginous aquatic products need solid phase extraction. LOD of the method was 0.03μg/kg,LOQ was 0.1μg/kg,the average recoveries revised by internal standard were in the range of 107～113.0%,and the precision was in the range of 4.7～5.3%.Finally, we established a quick and accurate LC/MS~n method for simultaneously detecting the metabolites of nitrofuran antibiotics including furacillin,furazolidon,furaltadon and the metabolites of nitrofurantoin in aquatic products. The metabolites of nitrofuran was separated from protein of zoogenic tissue under acor conditions, derivatized by o-nitrobenzaldehyde, separated by chromatography after distilling, qualitating by second order MS and quantitating by internal standard method, the average recoveries of added standard samples were in the range of 98%～112%(revised by internal standard), LOQ was 0.1-0.2μg/kg and LOD was 0.05-0.1μg/kg.The results showed that the method of high performance liquid chromatography tandem mass spectrometry built above was suitable for simultaneously detecting the residues of avermectins,chloramphenicol and the metabolites of nitrofuran antibiotics in aquatic products. The accuracy of the method could completely according with the requirement of EU and USA that the criterion laboratory could meet the need of basic technology of analyzing the residues of veterinary drugs in the agricultural products.