Determination Of Nitroimidazole Residues In Fresh Meat By Ultra High Performance Liquid Chromatography Tandem Mass Spectrometry

A method for the quantitative determination of four nitroimidazoles and their metabolites in fresh meat by ultra high performance liquid chromatography tandem mass spectrometry(Ultra high performance liquid chromatography-tandem mass spectrometry,UPLC-MS / MS)was established.Two pretreatment schemes were optimized:(I)pass through purification mode: the sample was extracted by 80% acetonitrile aqueous solution containing 1% formic acid and purified by Oasis prime HLB,Determination after concentration;(II)adsorption elution purification mode: the sample was extracted by methanol containing 1% formic acid,purified by a new strong cation exchange solid phase extraction column oasis prime MCX,and determined after concentration.The two methods were separated by ultra high performance liquid chromatography,electrospray ionization(Electrospray ionization,ESI)with three quadrupole mass spectrometry,positive ion multiple reaction monitoring mode(Multi reactive ion monitoring,MRM),and quantified by matrix external standard method.The results showed that the linear relationship between the two purification schemes and the four nitroimidazoles and their metabolites in beef,mutton and pork was good,the correlation coefficient was not less than 0.9980,the detection limit and quantitative limit were 0.3 ? g / kg and 1.0 ? g / kg,respectively,the recovery range was 63.14%-118.65%,and the relative standard deviation was less than 5.08%.Two different purification methods of the target through purification and target adsorption elution purification are combined to meet the detection requirements to the greatest extent.The method of SPE can also be used for the detection of benzimidazoles and their metabolites in fresh meat.The detection limit and quantitative limit of SPE are 0.05-0.3 ? g / kg and 0.1-1.0 ? g / kg,respectively.The recovery of standard addition is in the range of 81.3%-111.68%,and the relative standard deviation is less than 8.22%.The method is simple,rapid,efficient,sensitive and can be used for the qualitative and quantitative determination of imidazoles and their metabolites in fresh meat.