DETERMINATION OF MELAMINE IN MILK BY REVERSED PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY WITH DIODE ARRAY DETECTION

Abstract

A simple, rapid and accurate high performance liquid chromatography (HPLC) method has been used for detection of melamine in milk. Analysis was carried out on C-18 column using an isocratic elution system of 0.10% TFA/methanol (70:30). The flow rate was 1.0mL min^-1 and the detection was performed at 240nm. No interfering peaks were observed with an overall analytical run time of 18 min. The calibration curve was found to be linear with the regression equation y = 0.411 x + 2.0737, and a correlation coefficient of 0.9892 (R²) over a concentration range of 1–40 µg/ml. The method yielded good results with a detection limit of 0.26µg/ml and a quantification limit of 0.47µg/ml. Melamine was recovered in range of 92.6-97.2%  with relative standard deviation of less than 8.3% (n=3). The method is simple, cost effective and does not require any preliminary treatment of the samples.