Huang Lingli, Xiao Aiguo, Fan Shengxian, Yin Juyi, Chen Pin, Liu Dengcai, Qiu Yinsheng, Wang Yulian, Yuan Zonghui
Reference Laboratory State of Veterinary Drug Residues, MOA Key Laboratory of Food Safety Evaluation, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China.
J AOAC Int. 2005 Mar-Apr;88(2):472-8.
Quinocetone (QCT), a new antimicrobial growth promotant of quinoxalines, can effectively improve the growth and feed efficiency of food animals with more safety than is provided by olaquindox and carbadox. To clarify its metabolism and residue levels in animals, a liquid chromatographic method with UV-Vis detection was developed for the determination of QCT and its main metabolites, desoxyquinocetone (DQCT) and 3-methylquinoxaline-2-carboxylic acid (MQCA), in muscle, liver, kidney, and fat of swine and chicken. For sample pretreatment, QCT and DQCT were extracted with ethyl acetate and purified with iso-octane; after alkaline hydrolysis of the tissue, MQCA was extracted with ethyl acetate and citric acid buffer (pH 6.0), and the extract was purified over a cation-exchange column (AG MP-50 resin). Detection was at 312 and 320 nm for QCT and DQCT, respectively, and at 320 nm for MQCA. The observed limit of detection for the 3 compounds was 0.025 microg/g in various tissues. The methods were linear over the concentrations range of 0.01-0.64 microg/mL with mean recoveries of approximately 71-86% and relative standard deviations of about 4-12% at the levels of 0.05, 0.10, and 0.20 microg/g. The method is highly selective and can be applied to the determination of QCT and its main metabolites in animal tissues, which would accelerate the pharmacokinetic and residue study of QCT in food animals.
喹烯酮（QCT）是一种新型喹喔啉类抗菌生长促进剂，与喹乙醇和卡巴氧相比，它能更有效地提高食用动物的生长性能和饲料效率，且安全性更高。为阐明其在动物体内的代谢情况和残留水平，建立了一种带有紫外可见检测的液相色谱法，用于测定猪和鸡的肌肉、肝脏、肾脏及脂肪中的QCT及其主要代谢物脱氧喹烯酮（DQCT）和3-甲基喹喔啉-2-羧酸（MQCA）。样品预处理时，用乙酸乙酯提取QCT和DQCT，并用异辛烷纯化；组织经碱性水解后，用乙酸乙酯和柠檬酸缓冲液（pH 6.0）提取MQCA，提取物通过阳离子交换柱（AG MP - 50树脂）纯化。QCT和DQCT的检测波长分别为312 nm和320 nm，MQCA的检测波长为320 nm。在各种组织中，这3种化合物的检测限均为0.025 μg/g。该方法在0.01 - 0.64 μg/mL的浓度范围内呈线性，在0.05、0.10和0.20 μg/g的添加水平下，平均回收率约为71 - 86%，相对标准偏差约为4 - 12%。该方法具有高度选择性，可用于动物组织中QCT及其主要代谢物的测定，这将加速QCT在食用动物体内的药代动力学和残留研究。
