tailieunhanh - Báo cáo khoa học: "Determination of Roxithromycin by Liquid Chromatography/ Mass Spectrometry after Multiple-Dose Oral Administration in Broilers"

Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Determination of Roxithromycin by Liquid Chromatography/ Mass Spectrometry after Multiple-Dose Oral Administration in Broilers | J. Vet. Sci. 2003 4 1 35-39 JOURNAL OF Veterinary Science Determination of Roxithromycin by Liquid Chromatography Mass Spectrometry after Multiple-Dose Oral Administration in Broilers Jong-hwan Lim Byung-kwon Park and Hyo-in Yun Division of Veterinary Pharmacology and Toxicology College of Veterinary Medicine Chungnam National University 220 Gung-dong Yuseong-gu Daejeon Korea Received January 30 2003 Accepted March 28 2003 Abstract A highly sensitive and specific method for the determination of roxithromycin in broiler tissues by LC MS w as developed and validated. A dichloromethane extract of the sample was separated on C18 reversed-phase column with acetonitrile-50 mM ammonium acetate 80 20 v v as the mobile phase and analyzed by LC MS via atm ospheric pressure ioni-zation electrospray ionization interface. The lim it of detection and limit of quantitation were 1 ng g and 5 ng g. The method has been successfully applied to determine for roxithromycin in various tissues of broilers. Residue concentrations were associated with administered dose. At the te rm in ation of treatment roxithromycin w as found in all collected sam ples for both dose groups. Liver was detected to have the highest residual concentration of roxithromycin. Residue concentrations of roxithromycin were low er than its LOQ in all tissues from both dose groups 10 days after the treatment of roxithromycin mixed with drinking water at a dose rate of 15 mg L or 60 mg L to each broiler for 7 days. Key words roxithromycin broiler LC MS withdrawal time Introduction Roxithromycin is a semisynthetic macrolide antibiotic de-r ived from erythromycin 12 . Roxithromycin was reported to be absorbed r apidly with the long elimination half t ime giving higher plasma levels than erythromycin 9 . Therefor e it can be effect ive at lower doses with less fr equent administrations which is regarded as an advantage in clinical settings. Due to these advantages it could be applied Corresponding author Hyo-in Yun .