Residue Depletion Of Nitrovin And Nifuroxazide In Broiler Chicken

Nitrofurans are a class of synthetic and broad-spectrum antibacterial drugs. Due to the low price and good treat effect, they were widely used as curative or feed additive in livestock and aquiculture. However, many nitrofurans and their metabolites have been proven to show potential carcinogenic and mutagenic effects. The broad use of these drugs will produce their residues in animal derived samples that are dangerous to the consumers, so the use of nitrofurans in livestock and quiculture has been prohibited in many countries, e.g. European Union, America, China, and Japan. The objectives of this study were to develop the high performance liquid chromatography methods (HPLC) to determine nitrovin, nifuroxazide and its acid-hydrolysable side-chain 4-hydroxybenzhydrazide, and to study their residue depletions in chicken.The limit of detection for nitrovin in tissue and plasma sample were 0.1 ng/g(mL) and the recoveries from the blank fortified samples were in the range of 71.1%-85.7%. The experiment began when the chickens were 15 days old, and birds were feed with feeds containing 10 mg/kg of nitrovin for 7 consecutive days. Five chickens were killed at withdrawal period of 0, 3, 7, 14, 21, 28d, and liver, kidney, fat, muscle and plasma were collected and determined by the HPLC method. The results showed that at withdrawal period of 0 days the residue concentration of nitrovin in plasma was the highest (average 84.98 ng/mL), compared with those in muscle, fat, liver and kidney (average 21.04, 61.18, 24.04, and 68.28 ng/g, respectively). At withdrawal period of 28 days, the residue levels of nitrovin in muscle, fat, liver and plasma were all higher than 1.0 ng/g(mL) and the highest concentration was in liver (average 5.8 ng/g).The limit of detection for nifuroxazide in tissue and plasma sample were 0.1 ng/g(mL) and the recoveries from the blank fortified samples were in the range of 71.0%-85.1%. The limit of detection for its acid-hydrolysable side-chain 4-hydroxybenzhydrazide (HBH) in tissue and plasma sample were 1pg/g(mL). The recoveries from the blank fortified samples of the free HBH were in the range of 71.4%-83.4% and that of for the tissue bound HBH were in the range of 57.2%-74.6%. The experiment began when the chikens were 7days old and the birds were feed with feeds containing 50mg/kg of nifuroxazide for 7 consecutive days. Five chickens were killed at withdrawal period of 0, 3, 7, 14, 21, 28d, and liver, kidney, muscle and plasma were collected and determined by the HPLC method. The results showed that nifuroxazide was metabolized in vivo and it was not detectable in these samples after 14 days of cessation. HBH was formed and at withdrawal period of 0 day its total residues in these samples were high: liver, 83.8 ng/g; kidney 38.5 ng/g; muscle, 49.4 ng/g; plasma, 22.1 ng/g. After 28 days of cessation, the total residues of HBH in these samples were still higher than 1.0 ng/g and the highest level was in liver (6.8 ng/g). Moreover, the concentrations of tissue-bound HBH were much higher than that of free HBH.In general terms, the high performance liquid chromatography methods (HPLC) for determination of nitrovin, nifuroxazide and its acid-hydrolysable side-chain 4-hydroxybenzhydrazide in the tissue and plasma of the chickens were developed and the residue depletion of these analytes in chicken were studied. The results are in support of the ban of nitrovin as a feed additive in food producing animals; the depletion behavior of nifuroxazide in chicken was similar to the previously found for other nitrofurans in chicken and the data provided a base for controlling the residue of nifuroxazide in the future.