摘要：

This paper describes a novel method to determine the degree of deacetylation of chitosan by 1 H NMR spectroscopy. Measurements were carried out at 70°C by using 2 wt% CD 3 COOD/D 2 O and 2 wt% DC1/D 2 O as solvents for chitosan. In the case of DC1/D 2 O system, effect on hydrolysis of chitosan should be taken into consideration, and the pulse repetition delay required for 45° pulse is 40s. Whereas, in regard to CD 3 COOD/D 2 O system, 6s pulse repetition delay is enough for 45° pulse, and moreover, high magnetic field NMR apparatus is necessary, because signal of CD 2 H residue in CD 3 COOD overlaps with that of CH 3 residue in N-acetyl residue and determination of the difference of two spectra is required. The proposed method is more effective, precise and simple, comparing with the conventional colloid titration and elemental analysis methods. Assignments of 1 H and 13 C NMR spectra of chitosan are also reported.

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