Furaltadone is a banned drug for use in food producing animals and the marker residue of furaltadone in edible tissues is its metabolite, 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ). In this study, a novel polyclonal antibody of furaltadone was produced by using of the conjugate of furaltadone-bovine serum albumin as immunogen. The obtained antibody showed good specificity and sensitivity toward AMOZ with an IC 50 value of 2.3 ng/mL. Then, an indirect competitive immunoassay (ELISA) with heterologous coating antigen was developed to directly determine AMOZ in animal meat with a simple sample preparation. The limit of detection for AMOZ in meat was 0.4 ng/g. At three fortification levels, the intra-and inter-assay recoveries from blank samples were in a range of 85.0%Á103%. The ELISA method was further confirmed with a HPLC method in which AMOZ was determined after derivatization with 2-naphthaldehyde. The two methods showed good agreement from the analysis of incurred pork samples.

In this study, the residue depletion of nitrovin in chicken was studied after feeding the birds with dietary feeds containing 10 mg/kg of nitrovin for 7 consecutive days. Tissues (muscle, fat, kidney, and liver) and plasma were collected at different withdrawal periods and determined by a high-performance liquid chromatography-ultraviolet (HPLC-UV) method. The limit of detection for nitrovin in tissue and plasma samples was 0.1 ng/(g or mL), and the inter- and intrarecoveries from the blank fortified samples were in the range of 71.1-85.7%. At the withdrawal period of 0 days, the residue concentration of nitrovin in plasma was the highest (average of 84.98 ng/mL) compared to those in muscle, fat, liver, and kidney (average of 21.04, 61.18, 24.04, and 68.28 ng/g, respectively). At the withdrawal period of 28 days, the residue levels of nitrovin in muscle, fat, liver, and plasma were all higher than 1.0 ng/(g or mL) and the highest concentration was in liver (average of 5.8 ng/g). These data are in support of the ban of nitrovin as a feed additive in food-producing animals.

The tissue-bound HBH could be used as a marker to monitor the residue of nifuroxazide in chicken and the best target tissue should be liver. This is the first paper reporting the residue depletion of nifuroxazide in chicken.