Spectrophotometric determination of deacetylation degree of chitinous materials dissolved in phosphoric acid.

A simple spectrophotometric method is proposed for determining deacetylation degrees (DD) of chitinous materials using phosphoric acid as the UV-transparent solvent system. Calibrating by the extinction coefficients (A(210)) of D-glucosamine and N-acetyl-D-glucosamine, DD values (24-88%) were computed numerically. The results correlated well (R(2) = 0.9805, n = 50) with those obtained by solid-state (13)C NMR. Comparison of the results obtained by the proposed UV method and solid-state (13)C NMR.

[1]  K. Chang,et al.  Heterogeneous N-deacetylation of chitin in alkaline solution , 1997 .

[2]  M. C. Ferreira,et al.  Determination of the degree of acetylation of chitin materials by 13C CP/MAS NMR spectroscopy. , 2001, International journal of biological macromolecules.

[3]  P. Methacanon,et al.  Heterogeneous N-deacetylation of squid chitin in alkaline solution , 2003 .

[4]  J. Synowiecki,et al.  Production, Properties, and Some New Applications of Chitin and Its Derivatives , 2003, Critical reviews in food science and nutrition.

[5]  O. Smidsrod,et al.  Compositional heterogeneity of heterogeneously deacetylated chitosans , 1996 .

[6]  E. Curotto,et al.  Quantitative determination of chitosan and the percentage of free amino groups. , 1993, Analytical biochemistry.

[7]  M. Hasegawa,et al.  Preparation of low-molecular-weight chitosan using phosphoric acid , 1993 .

[8]  Sek-Man Wong,et al.  The degree of deacetylation of chitosan: advocating the first derivative UV-spectrophotometry method of determination. , 1998, Talanta.

[9]  J. Desbrières,et al.  An infrared investigation in relation with chitin and chitosan characterization , 2001 .

[10]  M. N. R. Kumar.  A review of chitin and chitosan applications , 2000 .

[11]  K. Vårum,et al.  Quantitative determination of chitosans by ninhydrin , 1999 .

[12]  Richie L. C. Chen,et al.  Use of Chitosan Membrane from the Carapace of the Soldier Crab Mictyris brevidactylus for Biosensor Construction , 2003, Marine Biotechnology.

[13]  W. Zhong,et al.  A new linear potentiometric titration method for the determination of deacetylation degree of chitosan , 2003 .