Abstract: In order to establish a new method to quickly determine melamine in milk powder, a chemiluminescence (FI-CL) system of luminol and potassium permanganate was coupled with flow injection technology. In the method, the chemiluminescence (CL) reaction between luminol and potassium permanganate was significantly reduced by melamine. Under the optimal experimental conditions, melamine concentration in the range of 1 × 10-11 to 1 × 10-6 mol/L was linearly proportional to the depression of CL signals. The detection limit was 4.0 × 10-8 mg/L, with a RSD of 1.1% for 11 replicate determinations. The recovery rates for melamine in a certain brand of milk powder were in the range of 96.1% to 102.2%. This method has been successfully applied to the determination of melamine in real milk powder samples.

Key words: melamine, flow injection-chemiluminescence, luminol, potassium permanganate, milk powder