A rapid, acetonitrile-free, HPLC method for determination of melamine in infant formula

A simple, precise, accurate and validated, acetonitrile-free, reverse phase high performance liquid chromatography (HPLC) method is developed for the determination of melamine in dry and liquid infant formula. The separation is performed on a Kromasil C18 column (150 mm x 3.2 mm I.D., 5 microm particle size) at room temperature. The mobile phase (0.1% TFA/methanol 90:10) is pumped at a flow rate of 0.3 mL min(-1) with detection at 240 nm. Melamine elutes at 3.7 min. A linear response (r>0.999) is observed for samples ranging from 1.0 to 80 microg mL(-1). The method provides recoveries of 97.2-101.2% in the concentration range of 5-40 microg mL(-1), intra- and inter-day variation in <1.0% R.S.D. The limit of detection (LOD) and limit of quantification (LOQ) values are 0.1 microg mL(-1) and 0.2 microg mL(-1), respectively.