title: [Simultaneous analysis the residues of 20 hormones in foods of animal origin by liquid chromatography tandem mass spectrometry].
abstract: OBJECTIVE
  To develop a quick and accurate method for simultaneous determining the multi-residues of hormones in foods of animal origin by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and to investigate these residues in swine, bovine, egg and milk collected from local markets in Shenzhen.
  
  
  METHODS
  The sample was firstly extracted with acetonitrile, and then subjected to solid-phase extraction clean-up using HLB-NH2 cartridges after defatted with hexane, lastly detected by high performance liquid chromatography-tandem mass spectrometry. Identification was achieved by electrospray ionization (ESI) in both positive and negative mode using multiple reaction monitoring. Quantification was performed by internal standard calibration.
  
  
  RESULTS
  The study showed that there was a certain amount of endogenous hormones in collected samples. The limits of quantification were 0.5 - 1.0 microg/kg for 20 hormones in swine, bovine, egg and milk. Average recoveries were 60.4% -118.2%, and the relative standard deviations were 2.5% - 16.2%.
  
  
  CONCLUSIONS
  This method was quick and accurate which could be used for determination of hormones in foods of animal origin (such as swine, bovine, egg and milk).
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China. gliu_686@hotmail.com
authors.forename: Guihua
authors.initials: G
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Qin
authors.forename: Honghe
authors.initials: H
authors.lastname: Liu
authors.forename: Zhou
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004350:Drug Residues / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D012739:Gonadal Steroid Hormones / Q000032:analysis*; D008460:Meat / Q000032:analysis*; D008892:Milk; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013552:Swine; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D012739:Gonadal Steroid Hormones