title: Simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry.
abstract: OBJECTIVE
  To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry (GC-MS/MS).
  
  
  METHODS
  Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile (10:40:50, V/V/V). After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/tandem mass spectrometry using multiple reactional monitoring (MRM) with 2, 6-Diamino-4-chloropyrimidine (DACP) being used as an internal standard.
  
  
  RESULTS
  The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the four compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% (n=6). The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3.
  
  
  CONCLUSIONS
  This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.
authors.affiliation: Department of Contaminant Monitoring and Control, Institute of Nutrition and Food Safety, Chinese Centre for Disease Control and Prevention, Beijing 100050, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Miao
authors.forename: Sai
authors.initials: S
authors.lastname: Fan
authors.forename: Yong-Ning
authors.initials: YN
authors.lastname: Wu
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Ping-Ping
authors.initials: PP
authors.lastname: Zhou
authors.forename: Jing-Guang
authors.initials: JG
authors.lastname: Li
authors.forename: Hui-Jing
authors.initials: HJ
authors.lastname: Chen
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002417:Cattle; D002849:Chromatography, Gas; D005411:Flame Retardants / Q000032:analysis; D005506:Food Contamination; D008892:Milk / Q000737:chemistry*; D008969:Molecular Sequence Data; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry; D014227:Triazines / Q000737:chemistry*
chemical_list: D005411:Flame Retardants; D014227:Triazines; C004632:cyanuric acid; C067139:ammelide; C000089:ammeline; C011907:melamine