Fast quantification of free amino acids in food by microfluidic voltage-assisted liquid desorption electrospray ionization-tandem mass spectrometry.

A method based on microfluidic voltage-assisted liquid desorption electrospray ionization-tandem mass spectrometry (VAL-DESI-MS/MS) has been developed for fast quantification of free amino acids in food. Food extracts were transferred to the microfluidic platform and analyzed by liquid desorption ESI-MS/MS. Deuterated aspartic acid (i.