Optimization of carbohydrate silylation for gas chromatography

We developed and optimized a new carbohydrate mono- and disaccharides silylation reaction, replacing pyridine and requiring lower reaction temperature and less time. Our method consists of three basic steps. The first one is oxime formation, the second one silylate derivative and the last one gas chromatography separation and quantification with an internal standard. We evaluated several solvents, including acetonitrile, hydroxylamine and aniline. We found aniline to be the best reaction media for oxime formation with hydroxylamine hydrochloride. Among silylation agents we found N,O-bis(trimethyl)trifluoroacetamide (BSTFA) was the most efficient. Together these reagents favored both a short analysis time and fewer by-products. We evaluated the method with model solutions containing: arabinose and co-eluting xylose, fructose, glucose, sucrose and salicin (internal standard) and found it suitable for processed food analysis.