Rapid detection of melamine in untreated milk and wheat gluten by ultrasound-assisted extractive electrospray ionization mass spectrometry (EESI-MS).

A novel method based on ultrasound-assisted EESI-MS has been developed and applied to rapidly detect the presence of melamine in raw milk, wheat gluten and milk powder with no or minor sample pre-treatment; the high sample throughput and figures of merit make it specially useful for screening melamine levels well below the current safety limit in various food matrices.