Analysis of metabolites of nitrofuran antibiotics in animal-derived food by UPLC-MS/MS

Abstract

An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was used for the simultaneous detection of four metabolites of nitrofuran (NF) antibiotics in eight animal-derived foods, namely porcine muscle, chicken, fish, duck, pork liver, crab, shrimp, and egg. Briefly, the sample was first acid-hydrolysed, derivatised, and extracted by ethyl acetate. The extract was then analysed by UPLC-MS/MS. Later, sample pre-treatment and UPLC-MS/MS conditions were optimised. The results showed that the method had good linearity over the range of 0.5~50 μg·kg-1. The average recoveries were 80.3~119.0%, and the relative standard deviations (RSDs) were < 8.1 and < 10.9% for intra-assay and inter-assay precision, respectively. The limits of detection (LODs) for 3-amino-2-oxazolidinone (AOZ), semicarbazide (SEM), 5-morpholino-3-amino-2-oxazolidone (AMOZ), and 1-amino-hydantoin (AHD) were 0.1, 0.2, 0.2, and 0.4~0.5 μg·kg-1, respectively, and the limits of quantification (LOQs) for AOZ, SEM, AMOZ, and AHD were 0.4, 0.5, 0.5, and 0.8~1.0 μg·kg-1, respectively. The proposed method was used to detect NF residues in 100 animal-derived food samples and quality control samples. The results were close to those detected by the China national standard method GB/T 20752-2006, and the results of quality control samples were within the detectable ranges. The results can provide a theoretical basis for the detection of NF residues in different kinds of animal-derived foods.