Improved method for i.r. determination of the degree of N-acetylation of chitosan.
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%.
Baxter
A
A
Department of Food Studies, Humberside Polytechnic, Grimsby, UK.
Dillon
M
M
Taylor
K D
KD
Roberts
G A
GA
D000107:Acetylation; D000818:Animals; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry; D048271:Chitosan; D033364:Decapoda; D015394:Molecular Structure; D013055:Spectrophotometry, Infrared / Q000379:methods*
D002686:Chitin; C012693:N-acetylchitosan; D048271:Chitosan