金霉素和代谢物差向金霉素在肉鸡肌肉和肝脏中的残留分布

Residue Distribution of Chlortetracycline and Its Metabolite 4-Epi-chlortetracycline in Broiler Chicken Muscle and Liver

关键词:  金霉素  差向金霉素  残留分布  肉鸡肌肉  肉鸡肝脏

Key words:  chlortetracycline  4-epi-chlortetracycline  residue distribution  broiler chicken muscle  broiler chicken Liver

摘要:

旨在研究金霉素（CTC）、差向金霉素（ECTC）在肉鸡肌肉、肝脏中的残留分布情况。样品经提取液提取后过Oasis HLB SPE小柱净化，采用电喷雾正离子模式（ESI+）和多反应监测模式（MRM），用高效液相色谱-串联质谱仪检测。结果表明：该方法测定肉鸡肌肉和肝脏中CTC检测限和定量限分别为5.0、10.0μg/kg；ECTC检测限和定量限分别为20.0、30.0μg/kg。CTC和ECTC在肉鸡肌肉中平均回收率分别在73.0%~95.20%和81.80%~101.60%，相对标准偏差（RSD）分别在8.85%~12.18%和2.05%~9.29%；在肝脏中平均回收率分别在67.06%～90.80%和78.64%～106.98%，RSD分别在2.90%～8.88%和4.72%～9.48%。试验组鸡按体重以50 mg/kg-?d剂量内服CTC，连续5d，每天给药1次，肉鸡肌肉和肝脏中CTC、代谢物ECTC的残留量分别在给药后第1d、5d时达到最高；肉鸡肝脏中ECTC的残留量约占总残留量的1/2；停药后CTC及其代谢物ECTC代谢缓慢，在停药第6d时，仍能检测到CTC及其代谢物ECTC，但其残留量均低于最高残留限量（MRLs）。

Abstract:

A study on chlortetracycline（CTC）and 4-epi-chlortetracycline（ECTC）residue distribution was conducted in broiler chickens muscles and livers .The samples were extracted using （extracting solution）and purified by Oasis HLB SPE column. Electrospray positive ion mode （ESI ）and multiple reaction monitoring（MRM）were adopted. Finally, Chlortetracycline (CTC) and 4-Epi-chlortetracycline (ECTC) in chicken muscle and liver were determinated by high performance liquid chromatography coupled with tandem quadruple mass spectrometry (HPLC-MS/MS) In this method, the limits of detection (LODs) and the limits of quantitation (LOQs) of chlortetracycline were5.0μg/kg and 10.0μg/kg, respectively; the LODs and LOQs of 4-Epi-chlortetracycline were 20.0μg/kg and 30.0μg/kg, respectively. The average recoveries in broiler chicken muscles were 73.0%~95.20% and 81.80% ~101.60%, with the relative standard deviation (RSD) of 8.85%~12.18% and 2.05%~9.29%, respectively; the average recoveries in broiler chicken livers were 67.06%~90.80% and 78.64%~06.98%, with the RSD of 2.90%~8.88% and 4.72%~9.48%, respectively. After the chickens were orally administered successively chlortetracycline of 50 mg/kg of body weight one time every day for 5 days, the residues of chlortetracycline and 4-Epi-chlortetracycline in broiler chicken muscles and livers were the highest on day 1 and day 5, respectively. The residues of 4-epi-chlortetracycline in broiler chicken livers accounted for half of the total residues. The metabolism of CTC and its metabolite ECTC was slow and could still be detected 6 days after withdrawal of drugs under the limits of the maximum residues (MRLs).