title: Development and validation of a liquid chromatographic/ tandem mass spectrometric method for determination of chlortetracycline, oxytetracycline, tetracycline, and doxycycline in animal feeds.
abstract: A selective and accurate LC/MS/MS method for the simultaneous determination of chlortetracycline (CTC), oxytetracycline (OTC), tetracycline (TC), and doxycycline (DC) in animal feeds was developed. Samples were extracted with Na2EDTA-McIlvaine buffer and further purified with Oasis HLB SPE columns. The purified extract was separated on an Xbridge C18 column and detected by LC/MS/MS with positive electrospray ionization in the multiple reaction monitoring mode. This method provided average recoveries of 80.9 to 119.5%, with CVs of 1.7 to 9.8% in the range of 0.5 to 50 mg/kg CTC, OTC, TC, and DC in feeds, except the average recovery of CTC was 76.0%, with a CV of 14.6% in pig feed spiked with 0.5 mg/kg CTC. The linear ranges for the four TCs determined by LC/MS/MS ranged from 0.005 to 2.5 microg/mL with a linear correlation coefficient (R2) >0.99. The LOD and LOQ for CTC, OTC, TC, and DC in pig and poultry feeds ranged from 0.003 to 0.02 and 0.01 to 0.05 microg/g, respectively. The method was successfully applied for the analysis of 30 real feed samples, and no illegal use was detected.
authors.affiliation: China Agricultural University, State Key Laboratory on Animal Nutrition, Beijing 100193, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Guo
authors.forename: Yiqiang
authors.initials: Y
authors.lastname: Chen
authors.forename: Liying
authors.initials: L
authors.lastname: Zhang
authors.forename: Wenjun
authors.initials: W
authors.lastname: Yang
authors.forename: Pingli
authors.initials: P
authors.lastname: He
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002751:Chlortetracycline / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods*; D004318:Doxycycline / Q000032:analysis*; D005504:Food Analysis / Q000379:methods; D007477:Ions; D008956:Models, Chemical; D010118:Oxytetracycline / Q000032:analysis*; D011200:Poultry; D012015:Reference Standards; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013552:Swine; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013752:Tetracycline / Q000032:analysis*
chemical_list: D007477:Ions; D013752:Tetracycline; D004318:Doxycycline; D002751:Chlortetracycline; D010118:Oxytetracycline