Abstract:

A method for the determination of melamine in animal-derived foods by ultra performance liquid chromatography (UPLC) was established. Egg samples were extracted with a mixture of 1% trichloroacetic acid and acetonitrile (3:1, V/V) and cleaned up using a PCX-SPE column, and the chromatographic separation was achieved on a CR column filled with a mixture of SCX and C18 (1:4, m/m). Melamine in rabbit meat samples was extracted with acetonitrile and injected without clean up into a PAK SCX UG80 column for the chromatographic separation. The detection was performed at UV wavelength of 236 nm. For the analysis using CR column, the calibration curve was linear in the range of 1.00－5.00 mg/L. The average recoveries of melamine in eggs spiked at three levels (1.00, 2.00 and 5.00 mg/kg) were 89.24%－91.06%, with a relative standard deviation less than 6.00%. For the analysis using PAK SCX UG80 column, the calibration curve was linear in the range of 0.4－4 mg/L. The average recoveries in rabbit meat spiked at three levels (2.00, 5.00 and 10.00 mg/kg) were 82.65%－86.54%, with a relative standard deviation less than 7.50%. This method is simple, and its sensitivity, accuracy and prevision all can meet the analytical requirements for melamine.

Key words: melamine, egg, rabbit meat, UPLC