Determination of Erythromycin Residue in Fishery Products by High Performance Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry

An analytical method was developed to detect residue of erythromycin in fishery products by high performance liquid chromatography-electrospray ionization tandem mass spectrometry. The erythromycin was extracted with acetonitrile, defatted with hexane, and purified with HLB solid phase extraction column. The quantification was performed with internal standard method, the erythromycin isotope label as internal standard. The recoveries of erythromycin were in the range of 87.0% - 97.8% with spiked levels of 1.0 - 20.0 g/kg. The relative standard deviations were less than 10% for intra-day and less than 5% for inter-day. The linear range of the method was from 1.0 to 100 mu g/L. The detection limit of the method was 1.0 g/kg.