Determination of dicyandiamide in dairy products by high performance liquid chromatography

A high performance liquid chromatographic (HPLC) method for the determination of dicyandiamide in dairy products was developed. The sample was extracted by acetonitrile, separated on an XBridge Amide column (250 mm x 4.6 mm, 3.5 mu m) using acetonitrile-water (90/10, v/v) containing 0.2% (v/v) formic acid as the mobile phase at a flow rate of 1.0 mL/min, and determined by a photodiode array detector at the wavelength of 218 nm. The calibration curve was linear in the range of 0.5 - 50 mg/L with the correlation coefficient (r(2)) of 0.999 9. The recoveries were from 96.7% to 101.0% with the relative standard deviations (RSDs) in the range of 4.5% to 4.9% (n = 6). The limit of detection was 0.2 mg/kg, and the limit of quantification was 0.5 mg/kg. The method is simple, sensitive, accurate and precise for the determination of dicyandiamide in dairy products.