A method for hexosamine measurement in chitin hydrolysates

摘要

A simplified procedure for measuring water-soluble hexosamines in chitin hydrolysates has been developed. The analysis is performed in a single test tube and involves hydrolysis with 2 M HCl for 3 h, followed by the Elson-Morgan colorimetry or the Somogyi-Nelson colorimetry. The procedure is based on the possibility of incomplete HCl neutralization after the stage of hydrolysis. Although glucosamine is not affected at the stage of hydrolysis, N-acetyl-D-glucosamine, which undergoes partial decomposition under these conditions, is used for calibration (the instability of the compound is taken into account in building the calibration curve). The content of hexosamines in chitodextrin preparations, measured by the method, is in precise agreement with the result of total nitrogen measurement by the Kjeldahl method. The new method has been used in gel chromatography of chitin oligosaccharides.