Screening method for veterinary drugs in livestock foods and fish by liquid chromatography/tandem mass spectrometry

The applicability of liquid chromatography/iontrap tandem mass spectrometry (iontrap LC/MS/MS) to screening for 44 veterinary drugs in livestock foods and fish was examined. Mass spectral acquisition was performed in both the positive and negative modes. In LC separation, a CadenzaCD-C18 column was used with 0.1% formic acid-acetonitrile as the mobile phase. The drugs were extracted from livestock foods and fish with acetonitrile/hexane saturated acetonitrile, and cleaned up by a OasisHLB cartridge. The precursor ion and product ions obtained under the EPI mode were key criteria to confirm the identity of veterinary drugs in samples. The MRM mode was obtained with a sensitive analysis. The iontrap LC/MS/MS technique is useful for screening residual veterinary drugs present at low levels in livestock foods and fish.