Simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry.
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.
Miao
Hong
H
Department of Contaminant Monitoring and Control, Institute of Nutrition and Food Safety, Chinese Centre for Disease Control and Prevention, Beijing 100050, China.
Fan
Sai
S
Wu
Yong-Ning
YN
Zhang
Lei
L
Zhou
Ping-Ping
PP
Li
Jing-Guang
JG
Chen
Hui-Jing
HJ
Zhao
Yun-Feng
YF
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*
D005411:Flame Retardants; D014227:Triazines; C004632:cyanuric acid; C067139:ammelide; C000089:ammeline; C011907:melamine