Matrix effects in the simultaneous determination of fenicol antibiotics in swine muscle and casings by ultra performance liquid chromatography-tandem mass spectrometry

Abstract

Animal tissue samples were extracted with ethyl acetate or alkalized ethyl acetate, and purified with MCX or LC-18 solid-phase extraction columns, and the matrix effects (ME%) in the simultaneous determination of four fenicol antibiotics including chloramphenicol (CAP), thiamphenicol (TAP), florfenicol (FF), and florfenicol amine (FFA) were studied by ultra performance liquid chromatography-tandem mass spectrometry. ME% for FFA in swine muscle and casings extracted by ethyl acetate with LC-18 column cleanup were 11.1% and 10.4%, and in swine muscle extracted by ethyl acetate and alkalized ethyl acetate with MCX column cleanup ME% were 8.1% and 16.1%, respectively, showing strong signal suppression; while ME% for FF in swine muscle extracted by ethyl acetate and alkalized ethyl acetate with LC-18 column cleanup were 148.5% and 146.9%, and in swine muscle extracted by ethyl acetate and alkalized ethyl acetate with MCX column cleanup were 234.3% and 150.9%, showing strong signal reinforcement. Deuterated chloramphenicol-d5 could only be used as an internal standard to eliminate matrix effects for CAP determination. It may be that the most effective method to eliminate matrix interference in the simultaneous determination of the four analytes is quantified by using matrix-matched solutions. Under the optimum conditions of sample pretreatment and quantitative analysis, the decision limits (ccα as specified in European Directive 2002/657/EC) for FFA, TAP, CAP and FF in swine muscle were determined to be 0.4, 0.05, 0.02 and 0.02 μg kg−1, and 0.5, 0.1, 0.04 and 0.03 μg kg−1 in casings; the detection capabilities in swine muscle were determined to be 0.7, 0.09, 0.05 and 0.05 μg kg−1, and 1.2, 0.19, 0.12 and 0.07 μg kg−1 in casings, respectively.