Indicators, absorption maxima definition

There is very little information on the preparation of polysaccharide adducts. Senti and Witnauer28 have reported the only polysaccharide adducts of a definite stoichiometric type. Their method consisted of equilibrating the alkali metal hydroxide adduct (see Section III) of the polysaccharide with the proper salt in 20-25% aqueous ethanolic medium. Absorption of salt, with concurrent displacement of hydroxide, increases with increase in concentration of the salt in the exchange medium. Above certain concentrations of the salt, absorption can become virtually independent of the concentration, indicating that maximum absorption has been attained and that a stable adduct of definite stoichiometric compo-... 

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