Characterization of chitosan by gel permeation chromatography - Influence of preparation method and solvent.

In this work, samples of chitosan obtained in different conditions were characterized by molecular weight distribution, using Gel Permeation Chromatography (GPC), in two different solvents. It was observed that the increase in the number of deacetylation steps promotes a increase in the degree of deacetylation followed by a decrease in the average of molecular weight and polydispersion. The GPC curves obtained for chitosan samples in the two solvents used (CH3COOH 0.30 mol/dm(3) CH3CONa 0.20 mol/dm(3) and CH3COOH 0.10 mol/dm(3) - NaCl 0.20 mol/dm(3)) showed small difference in elution volume, but significant changes in the average molecular weight (M-n and M-w) and polydispersion that, in agree with the values of Huggins constant, present evidences of chitosan aggregates formation in the second solvent.