INTRODUCTION Recent investigations of death and health problems of babies in China have revealed that some baby foods (milk powder) have been contaminated by melamine (structure shown in Figure 1). Some manufacturers illegally used melamine as an adulterant to increase the apparent protein content. Standard methods enacted by the Chinese government for determining melamine in raw milk and dairy products included HPLC-UV, LC-MS, and GC-MS methods.However, the high cost of operation and maintenance of GC/LC-MS systems as well as the labor intensive derivatization that GC-MS requires limits their use in the milk product factories. The HPLC-UV method therefore is presently the popular choice for most factories. In this method, melamine is separated on a C8 or C18 column using an ion pair buffer (mixture of citric acid and sodium 1-octane sulfonate) and acetonitrile mobile phase.