Determination of degree of substitution for N-acylated chitosan using IR spectra

摘要

Chitosans with various degrees of deacetylation (D. D.), which were used as standard sample for FTIR determination, were prepared from completely deacetylated chitosan by homo- geneous N-acetylation reaction. By combining four probable probe bands, i.e. 1655, 1560, 1380 and 132 cm~-1, eight probable reference bands, i.e. 3430, 2920, 2880, 1425, 1155, 1070, 1030 and 895Cm~-1, and two baseline methods, the most suitable ratios A_probe band/A _reference band from IR spectra to determine the degree of acetylation of chitosan were evaluated from 48 combinations to be A_1560/A_2880, A_1560/A_2920 and A_1655/A_3430(A_1560/A_2880 is mostly recommended).