Fast determination of chloramphenicol residues in milk by HPLC-MS / MS

Objective To develop a liquid chromatography- mass spectrometry( HPLC- MS / MS) method for determining the chloramphenicol residues in milk. Methods With high performance liquid chromatography- electrospray ionization quadrupole mass spectrometer,the protein in sample was precipitated by acetonitrile. The chloramphenicol was extracted with acetic ether and enriched by rotary evaporation,chromatographic separation was carried out on a Thermo Hypersil Gold column( 100 mm ×2. 1 mm × 3 μm). With mobile phase of 0. 1% methane acid- acetonitrile,electrospray ionization in the negative ion mode MRM was used in the detection. Results The limit of detection was 0. 004 μg / kg and the linear ranges were 0. 25 μg / kg ~1. 25 μg / kg with correlation coefficient 0. 9978. The average recovery was 98. 7%,and the RSD value was 0. 5%. Conclusion The chloramphenicol residues in milk could be rapidly determined by the HPLC- MS / MS method which was accurate and highly reproducible.