Determination of cyanuric acid in milk powder by anion-exchange chromatography

An anion-exchange chromatographic method has been developed for simultaneous analysis of cyanuric acid (CA) and five inorganic anions (F(-), Cl(-), NO(3)(-), HPO(4)(2-) and SO(4)(2-)) in milk powder. The separation was achieved within 15 min on an anion-exchange column with simple elution of Na(2)CO(3)/NaHCO(3) buffer as mobile phase. Furthermore, the effect of the total concentration of Na(2)CO(3)/NaHCO(3) buffer on the retention of five inorganic anions was more obvious than that on CA retention, which indicated that CA retention on anion-exchange column depends not only on anion-exchange interaction but also on hydrophobic interactions between CA and anion-exchange column. The linear range of the calibration curve for CA was 0.1-100 mg L(-1). The detection limit calculated at S/N = 3 was 0.083 mg L(-1). The method was successfully applied to the analysis of CA in milk powder.