Project Number: 1235-52000-045-00
Project Type: Appropriated

Start Date: Feb 22, 2004
End Date: Feb 21, 2009

Objective:
To develop comprehensive methods for the determination of S and Se in proteins and free amino acids in foods. Of particular interest are the secondary metabolite (non-protein) amino acids that have been implicated in the prevention of chronic disease.

Approach:
Proteins and free amino acids will be separated from other food components. Proteins will be hydrolyzed chemically and/or enzymatically and methionine, cysteine, selenomethionine, and selenocysteine will be determined using high performance liquid chromatography (HPLC) or reaction with cyanogen bromide. Free amino acids will be separated and derivatized for separation by HPLC or gas chromatography (GC). S and Se-containing compounds will be identified using inductively coupled plasma-mass spectrometry (ICP-MS) or pulsed flame photometric detection (PFPD). The organic component of the non-protein amino acids will be characterized using HPLC-MS with electrospray ionization.