ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Determination of small amounts of HCl and of polyuronic acids and acidic polysaccharides, containing carboxyl groups

R. Kohn, V. Tibenský, and I. Furda

Slovak Academy of Sciences, Bratislava 9

Abstract: Poly(methacrylic acid), alginic acid, pectic acid, acidic pectin of various esterification %, and acidic apricose gum (Prunus armeniaca) were examd. The potentiometric titrn. with NaOH gives the sum of HCl and acidic polysaccharide. HCl in acidic polysaccharides, including poly(methacrylic acid), is detd. by argentometric and potentiometric titrns. with a mean error (+0.5 ± 0.1) × 10^-5 equiv. HCl/l., and with a mean error for a single detn. of 0 to 10 × 10^-5 equiv. HCl/l. Addn. of 1M KCl makes the titrn. curve steeper at the inflection point. The carboxyl group of the acidic polysaccharide and of the poly(methacrylic acid) is calcd. from the total amt. of NaOH used for the titrn. of both acids and from the argentometric detn. of HCl. For a concn. of 8 × 10^-4 to 2 × 10^-2 equiv. COOH/l., the mean error is ± 0.5%. Adding KCl in the detn. of acidic polysaccharides does not improve the end point. The detn. of a small amt. of HCl and of acidic polysaccharides in the presence of alkali metal chlorides is presented, with 1 example described.

Full paper in Portable Document Format: 194a259.pdf (in Slovak)

Chemical Papers 19 (4) 259–271 (1965)