Simultaneous UHPLC-MS/MS Determination of Chloramphenicol and Florfenicol in Aquatic Products with Accelerated Solvent Extraction

A method of UHPLC-MS/MS for the simultaneous determination of chloramphenicol and florfenicol in aquatic products was proposed. The sample was crushed and extracted with ethyl acetate under static condition at 100 ℃ for 5 min by accelerated solvent extraction (ASE). The extract was concentrated, dissolved in water and purified by extraction with n-hexane. Thermo Hypersil GOLD C18 chromatographic column was used as stationary phase, and a mixture of methanol and water in different ratios was used as mobile phase in gradient elution. The ionization modes of ESI- with SRM mode of detection were adopted in MS/MS determination. Linearity ranges of chloramphenicol and florfenicol were kept same from 0.02 to 10 μg·kg-1 with detection limits (3S/N) of 0.02 μg·kg-1 and lower limits of determination (10S/N) of 0.05 μg·kg-1. Tests for recovery were made by addition of standards of chloramphenicol and florfenicol at 4 different concentration levels to blank aquatic product samples, values of recovery found were in the range of 90.2%-109%, with values of RSD′s (n=6) in the range from 1.8% to 8.5%.