Determination of the Degree of Deacetylation in Chitosan and its Salts by Proton Nuclear Magnetic Resonance Spectroscopy

Document Type : compile

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Abstract

Chemical reactions on the structure of polymers, especially natural polymers result in
production of new properties. One of these cases is chitin deacetylation reaction for
production of chitosan. Property and application of chitosan with extensive uses in food,
cosmetic, healing and drug industries depend on the degree and percent of acetyl groups
or in other words the degree deacetylation (DDA). Proton nuclear magnetic resonance
spectroscopy (1HNMR) is the simplest, most accurate and fastest method for quantitative
determination of the degree of deacetylation in chitosan and its salts. In this method,
the degree of deacetylation, ranging from 50 to 100%, with acceptable accuracy and
repeatability is determined by a small amount of material without undergoing degradation
and simple calculation. In addition, if the molecular weight of polymer is low, this test
method can determine the number average degree of polymerization (DPn) in chitosan and
chitosan salts for use in biomedical and pharmaceutical applications.

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