EN
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed for the determination of melamine in feed samples. After a preliminary dissolution in acetonitryle and 0.05 M phosphate buffer, the obtained extract was sonicated for 10 min and supernatant was collected. The supernatant was cleaned up on SCX solid phase extraction cartridges. Melamine was determined, using electrospray ionisation in the positive mode, followed by separation on the carbon column Thermo Hypercarb. The whole procedure was validated for the identification and determination purposes. Feed samples were spiked with melamine solution at levels corresponding to 0.5-1.0-2.5-10.0 mg/kg. At the studied levels, trueness ranged between 78.0% and 82.3% and within-laboratory reproducibility expressed as a relative standard deviation was lower than 15%. The limit of detection was estimated at the level of 0.58 mg and limit of quantitation was 0.65 mg/kg.