Résumé : Synthetic mixtures of 15 of the 18 most common amino acids (cystine, methionine and tryptophan excepted) were boiled with 6N HCl in the presence and absence of carbohydrate. The decomposition products from starch and glucose do not interfere with the chromatographic determination of the amino acids on ion exchange columns. In no instance was the observed recovery of an amino acid lowered by as much as 3 per cent by the addition of carbohydrate (2 g) to 25-50 mg of amino acids per 200 ml 6N HCl. The dilute conditions of hydrolysis correspond to those adopted for the determination of the amino acid composition of foods of high carbohydrate content. © 1953.