[Analysis of polysaccharides used as food additives. V. Gaschromatographic identification of hydrolysis products in uronic acids containing polysaccharides].

Alduronic acids can be found among the monomeric units of polysaccharides, which are used as stabilisators in the food industry. Gaschromatographically they cannot be separated directly by the way of their aldonitrilacetates but it is possible by the procedure described. The 1-0-methylalduronic-acidmethylesters, obtained by the methanolysis of the polysaccharides, are reduced with boronhydrid to the corresponding methyl glycosides; there are split with acid to the aldoses, which are converted in pyridine with hydroxylamine to the aldoximes and than with acetic anhydride to the aldonitrilacetates, which can be separated by gaschromatography without difficulty.