Determination of olaquindox,carbadox and cyadox in animal feeds by ultra-performance liquid chromatography tandem mass spectrometry

Olaquindox, carbadox, and cyadox are chemically synthesised antibacterial and growth-promoting agents for animals. At high doses they may exert mutagenicity and hepatic and adrenal toxicities in animals. Regrettably, these substances are frequently abused or misused when added into animal feeds. Thus, developing a sensitive and reliable method for simultaneous determination of olaquindox, carbadox, and cyadox in different kinds of animal feeds is crucially important for food safety monitoring. In this paper we optimised instrumental conditions, extraction solvents, solid phase extraction cartridges, and pH of the loading solvents on the Oasis HLB cartridge. Under the optimal conditions, mean recoveries ranged from 74.1 to 111%, and intra-day and inter-day variations were lower than 14.6% and 10.8%, respectively. The limits of quantification for olaquindox, carbadox, and cyadox were 0.05 mg kg^?1, 0.10 mg kg^?1, and 0.025 mg kg^?1, respectively. The proposed method uses ultra-performance liquid chromatography tandem mass spectrometry and is sensitive and reliable for the simultaneous determination of olaquindox, carbadox, and cyadox in three kinds of animal feeds (specifically, mixed feed, concentrated feed, and additive premixed feed). This method has good precision, high sensitivity, and good reproducibility, and thus it can be used for convenient and accurate determination of olaquindox, carbadox, and cyadox in different kinds of animal feeds.     

超高效液相色谱-三重四级杆质谱法测定牛干巴中2种喹噁啉类药物残留

目的建立超高效液相色谱-三重四级杆质谱法测定牛干巴中卡巴氧及喹赛多的含量的分析方法。方法样品经乙酸乙酯-乙腈提取,正己烷脱色净化后,以乙腈-0.1%甲酸溶液为流动相,经ACQUITYTMBEH18柱分离,采用多反应监测正离子模式进行定性及定量分析。结果卡巴氧及喹赛多的检出限分别为0.2和2.0μg/kg, 3个加标水平回收率范围为66.4%～115.0%,相对标准偏差为4.2%～8.2%。结论该方法灵敏度高、重复性好、准确度高、分析时间短、样品前处理操作简便,适用于牛干巴中卡巴氧及喹赛多的测定。     

Estimation of residue depletion of cyadox and its marker residue in edible tissues of pigs using physiologically based pharmacokinetic modelling

Physiologically based pharmacokinetic (PBPK) models are powerful tools to predict tissue distribution and depletion of veterinary drugs in food animals. However, most models only simulate the pharmacokinetics of the parent drug without considering their metabolites. In this study, a PBPK model was developed to simultaneously describe the depletion in pigs of the food animal antimicrobial agent cyadox (CYA), and its marker residue 1,4-bisdesoxycyadox (BDCYA). The CYA and BDCYA sub-models included blood, liver, kidney, gastrointestinal tract, muscle, fat and other organ compartments. Extent of plasma-protein binding, renal clearance and tissue-plasma partition coefficients of BDCYA were measured experimentally. The model was calibrated with the reported pharmacokinetic and residue depletion data from pigs dosed by oral gavage with CYA for five consecutive days, and then extrapolated to exposure in feed for two months. The model was validated with 14 consecutive day feed administration data. This PBPK model accurately simulated CYA and BDCYA in four edible tissues at 24–120 h after both oral exposure and 2-month feed administration. There was only slight overestimation of CYA in muscle and BDCYA in kidney at earlier time points (6–12 h) when dosed in feed. Monte Carlo analysis revealed excellent agreement between the estimated concentration distributions and observed data. The present model could be used for tissue residue monitoring of CYA and BDCYA in food animals, and provides a foundation for developing PBPK models to predict residue depletion of both parent drugs and their metabolites in food animals.     

喹赛多对肉用齐卡兔生产性能的影响

选择30日龄体重基本一致的齐卡兔60只(公、母各半),随机分成5组,其中对照组饲喂基础日粮,试验组分别在基础日粮中添加喹赛多50 mg/kg、喹赛多100 mg/kg、喹乙醇50 mg/kg和喹乙醇100 mg/kg,进行为期60 d的饲养试验;研究喹赛多和喹乙醇对肉用齐卡兔生产性能的影响.结果表明:试验组与对照组相比,平均日增重提高显著(P＜0.05);100 mg/kg喹赛多组与对照组日耗料量相当,而其它各组日耗料量则显著低于对照组(P＜0.05);试验组与对照组相比料重比降低显著(P＜0.05),但试验组间差异不显著(P＞0.05);试验组肉兔腹泻率降低.喹赛多组优于喹乙醇组,其适宜添加量为100 mg/kg.