Abstract: A method is presented for the quantitative determination and confirmation of cyanuric acid in infant formula by mixed-mode solid-phase extraction cartridge clean up-gas chromatography-mass spectrometry (GC-MS). Cyanuric acid was extracted from infant formula with an acetic acid solution at 84 ℃. An aliquot of the supernatant was cleaned up using mixed-mode solid-phase extraction cartridge containing C18 and graphitized carbon black (GCB), and evaporated to dryness under nitrogen. The residues were converted to trimethylsilyl derivatives, then determined by GC-MS in selected ion monitoring (SIM) mode. The linear range was from 0.01－2 mg/L. The recoveries were 80%－103% and the relative standard deviations were 7.7%－14.5% in the spiked range of 0.25－2.5 mg/kg. The limit of detection was 0.10 mg/kg and the limit of quantification was 0.25 mg/kg. The method is rapid, sensitive, accurate, specific, and rugged. It is suitable for the quantitative determination and confirmation of cyanuric acid in infant formula.

Key words: cyanuric acid, infant formula , mixed-mode solid-phase extraction cartridge clean up, gas chromatography-mass spectrometry(GC-MS)