[Simultaneous determination of polyether antibiotics and macrolide anthelmintics in livestock products by liquid chromatography/tandem mass spectrometry]

A method using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of polyether antibiotics and macrolide anthelmintics in livestock products. The polyether antibiotics and macrolide anthelmintics were extracted from livestock products with acetonitrile and cleaned up with dispersive solid-phase extractions and a silica gel column. The quantification limits of polyether antibiotics and macrolide anthelmintics were 0.00005-0.0005 µg/g. Except for narasin and lasalocid in bovine liver and milk, the recoveries were 70 to 117%. The relative standard deviations met the required guideline. The developed method was applied to six kinds of livestock products.