GC-MS Analysis of Monosaccharide Mixtures as their Diethyldithioacetal Derivatives: Application to Plant Gums Used in Art Works

摘要

Asimple GC-MS method has been studied for the determination of aldoses and uronic acids in polysaccharide hydrolysates. Unlike other methods, the derivatisation procedure give a single peak for each particular monosaccharide, including uronic acids. The method has been applied to plant gums used in decorative artefacts. A sample of gum, after acid hydrolysis, is first mercaptalated with a mixture of ethanethiol and trifluoroacetic acid (2:1) and then derivatized in the same vessel. The obtained diethyldithioacetal trimethylsilylates or peracetates are separated by capillary column gas chromatography on SE-54 stationary phase. The chroma-tographic retention indices and El mass spectra of monosaccharide standards are reported to -gether with composition data for six plant gums.