This report described a method for simultaneous determination of cyanuric acid (CYA) and melamine
(MEL) in dairy products. The samples were extracted by a mixture of acetonitrile/water and cleaned by
graphite carbon/strong cation exchange (CARB/SCX) mixed-mode solid phase extraction column. The
CYA and MEL were derivatized with bis(trimethylsily1)trifluoroacetamide (BSTFA) containing 1% Trimethylchlorosilane
(TMCS), and quantified with the internal standards of 15N3-cyanuric acid and
13C3-melamine by GCeMS. The results indicated that CARB/SCX mixed solid phase extraction column
could be used for sample pretreatment. The fortification recoveries were 80.8e101.5%, and the relative
standard deviations (RSDs) were 3.6e7.9%. The detection limits of CYA and MEL were 0.025 mg kg1 and
0.01 mg kg1 respectively.