A novel mixed-mode solid phase extraction for simultaneous determination of melamine and cyanuric acid in food by hydrophilic interaction chromatography coupled to tandem mass chromatography.

Utilizing a solid phase extraction column (MCT) containing mixed hydrophilic functional gel and cation exchange sorbent, a sensitive and rapid HPLC-MS/MS method for simultaneously determining the residues of melamine (MEL) and cyanuric acid (CYA) in human foodstuffs was developed. MEL and CYA in egg, pork, liver, kidney and pork, shrimp, sausage casing, honey, soybean milk, soybean powder and dairy product were extracted using acetonitrile/water, defatted with hexane and isolated using MCT solid phase extraction column. The residues were separated upon a hydrophilic interaction liquid chromatography (HILIC) column and analyzed by electrospray ionization under negative-positive switched mode on a triplequadrupole mass spectrometry.