Abstract: The analytical method of melamine in milk and milk powder by high performance liquid chromatography (HPLC) was established. The sample was purified by a cation exchange solid-phase extraction column, separated on a Diamonsil C18 column (4.6 mm×200 mm, 5 μm) with acetonitrile-0.01 mol/L sodium heptanesulfonate (pH 3.3) (10∶90, v/v) as mobile phase at a flow rate of 1.0 mL/min, and determined by a photodiode array detector. A linear calibration curve was obtained in the concentration range of 1-500 mg/L. The qualification limit was 0.2 mg/kg, and the quantification limit was 1 mg/kg. The recovery was 81.4%-83.7%.

Key words: high performance liquid chromatography (HPLC), melamine, milk , milk powder, solid-phase extraction（SPE）