| Author | Shrestha, Anjala |
| Call Number | AIT Thesis no. BP-98-15 |
| Subject(s) | Chitosan
|
| Note | Thesis report submitted in partial fulfillment of the requirements for the degree of Master
of Science in Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | New methods are proposed for determining the degree of deacetylation of chitosan.
Metal adsorption, ninhydrin and Ehrlich's reagent were used to quantify -NH2 content in chitin
and chitosan. In solid state, chitin shows less adsorption capacity as compared to chitosan
There is a decrease in Cu(Il) adsorption as % DD increases. Spectrometric determination of
metal ions is not enough sensitive to distinguish among the samples. So the metal adsorption
method has not enough accuracy to determine the % DD of chitosan.
Direct absorbance of dilu te solution of chitosan in 0.1 M acetic acid at a concentration
of 0.01 g of chitosan per litre shows maximum absorbance at 190 nm. At this wavelength,
chitosan of different % DD (60%, 75%, 86% and 95%) gives a straight line having a negative
slope which is due to absorbance of N-acetylglucosamine moieties. This technique can be used
to detect % DD by comparing with the standard curve of% DD at 190 nm.
Ehrlich's reagent can directly react with a chitosan dissolve in 0. 1 M acetic acid. The
final chromogen has OD at 410 nm and it has also linear relationship between concentration
and absorbance. A good straight line is obtained with % DD of chitosans and their absorbance
at 5 mg/ml concentration. By estimating the amount of glucosamine in the sample, % DD is
calculated. This method estimates lower value of -NH2 than the reference method, i. e. Acid
hydrolysis-HPLC method.
There is no significant difference between the water-binding capacity of chitin and
chitosan samples tested in a saturated environment of water at room temperature (22-25°C).
Equlibrium is reached after 24 hours of putting in saturated environment of water. In dry
ambiance, dehydration of chitin and chitosan is very fast in first 24 hours. |
| Year | 1998 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Bioprocess Technology (BP) |
| Chairperson(s) | Didier, Montet; |
| Examination Committee(s) | Stevens, Willem F. ;Suwalee Chandrkrachang ;Rakshit, Sudip Kumar ;Pakorn Nuchnoi ; |
| Scholarship Donor(s) | H.M.King's Scholarship, Thailand ; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1998 |