Determination of melamine in milk powder, milk and fish feed by capillary electrophoresis: a good alternative to HPLC.

BACKGROUND: Since September 2008, an increased incidence of kidney stones and renal failure in infants, associated with the ingestion of infant formula contaminated with melamine has been reported in China. Furthermore, melamine was not only found in many protein-based food commodities, but also in the feeds for cattle and poultry. So it is necessary to develop a suitable method to determine melamine. RESULTS: A capillary zone electrophoresis (CZE) method for analysis of melamine was developed by use of running electrolyte containing 35 mmol L−1 sodium dihydrogen phosphate at pH 3.5, with UV detection at 210 nm. Regression equation revealed linear relationships (r = 0.9999) between the peak-area and the content of melamine from 0.8 to 80 µg mL−1. The detection limit was 0.08 µg mL−1. The method was successfully applied to the determination of melamine in milk powder, milk and fish feed, with the recoveries from 94.5% to 103.7%. CONCLUSION: The performance of the CZE method evaluated in terms of precision, limits of detection, accuracy and quantification were comparable and in good agreement with those obtained by the HPLC method, with the advantage of shorter analysis time and lower cost. Copyright © 2010 Society of Chemical Industry