Simultaneous determination of florfenicol with its metabolite based on modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and evaluation of their degradation behavior in agricultural soils.

A simple and simultaneous method for the determination of florfenicol and its metabolite florfenicol amine in agricultural soils using modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and reversed-phase high-performance liquid chromatography with tandem mass spectrometry is presented. Florfenicol and its metabolite florfenicol amine residues in agricultural soils were extracted with alkalized acetonitrile and an aliquot was cleaned up with Si(CH2)3NH(CH2)2NH2 and C18 sorbent, which were powder materials. High-performance liquid chromatography with tandem mass spectrometry was applied to simultaneously determine the level of florfenicol and florfenicol amine in agricultural soils. Excellent linearity was achieved for florfenicol and florfenicol amine over a range of concentrations from 0.1-500 μg/L with coefficients more than 0.99. Average recoveries at four different levels (0.005, 0.05, 0.5, and 5.0 mg/kg) for florfenicol and florfenicol amine ranged from 73.6-94.9% with relative standard deviations of 2.9-12.5%. The limits of detection for florfenicol and florfenicol amine in agricultural soils were 2.0 μg/kg, and the limits of quantification were 6.0 μg/kg. Based on this method, the degradation behavior of florfenicol and its metabolite florfenicol amine in three soils (Nanchang, Hangzhou, and Changchun) under sterilized and native conditions was investigated and the transformation rate of florfenicol amine from florfenicol was evaluated.