DETERMINATION OF THE DEGREE OF SUBSTITUTION OF CHEMICALLY-MODIFIED CYCLODEXTRINS BY A MICROCALORIMETRIC TITRATION TECHNIQUE

The degree of substitution of chemically modified cyclodextrins (hydro xypropyl-beta-cyclodextrin, hydroxyethyl-beta- cyclodextrin and methyl -beta-cyclodextrin) could be determined by a microcalorimetric titrati on technique. A linear relationship was obtained between the degree of substitution and the enthalpy of dilution. Secondly, a strong depende nce of the heat effect on the concentration of cyclodextrin was demons trated. The accuracy of measurements was proved by dilution experiment s with propan-1-ol. The results are explained by comparison with entha lpy pair and triplet interaction coefficients of ethanol and propan-1- ol from the literature.