title: Improved method for i.r. determination of the degree of N-acetylation of chitosan.
abstract: Three published i.r. absorption band ratios for determining the % N-acetylation of chitosan have been used to follow the rate of alkaline deacetylation of chitin. Only one, the A1655/A3450 ratio, gives the expected rate of deacetylation curve. Consideration of the various i.r. ratios has led to a new relationship, % N-acetylation = (A1655/A3450) x 115, where the absorbance of the amide I band at approximately 1655 cm-1 is determined using the baseline proposed previously. The values obtained using this proposed relationship agree closely with those obtained from dye adsorption measurements for chitosans having % N-acetylation values in the range 0-55%.
authors.affiliation: Department of Food Studies, Humberside Polytechnic, Grimsby, UK.
authors.forename: A
authors.initials: A
authors.lastname: Baxter
authors.forename: M
authors.initials: M
authors.lastname: Dillon
authors.forename: K D
authors.initials: KD
authors.lastname: Taylor
authors.forename: G A
authors.initials: GA
authors.lastname: Roberts
mesh_terms: D000107:Acetylation; D000818:Animals; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry; D048271:Chitosan; D033364:Decapoda; D015394:Molecular Structure; D013055:Spectrophotometry, Infrared / Q000379:methods*
chemical_list: D002686:Chitin; C012693:N-acetylchitosan; D048271:Chitosan