RESUMO
Objective:To establish a method for the determination of chloramphenicol residue in Wuji Baifeng pills by liquid chro -matography tandem mass spectrometry with normal solid-phase extraction .Methods:A normal solid-phase extraction column was used for the sample pretreatment and enrichment , and high performance liquid chromatography tandem mass spectrometry was used to deter-mine chloramphenicol residue in Wuji Baifeng pills .The analysis was performed on an Agilent-ODS C18 (250 mm ×4.6 mm,5 μm) column .The mobile phase was composed of methanol and water with gradient elution at 40℃ (0-7 min, 30% methanol;7-15 min, 30%-80%methanol;15-25 min, 80%-30%methanol).The flow rate was 1.0 ml· min-1 , and the quantitation ion was m/z 152.1 (the negative ionization) under the mode of multiple reaction monitoring .Results:The limit of detection was 0.016 ng.The calibra-tion curves were linear within the range of 0.187-3.749 ng.The method recovery was 94.3% with RSD of 3.19%(n=9).Conclu-sion:The method is simple with accurate results .It is suitable for the determination of chloramphenicol residue .