| Summary: | 碩士 === 國立臺灣大學 === 生物產業機電工程學研究所 === 106 === Chitosan is an important biomaterial used widely in tissue engineering and environmental application. Degree of deacetylation (DD%) is the most important quality parameter of chitosan. Several methods have been developed to determine DD% for chitosan. NMR (Nuclear Magnetic Resonance) and FTIR (Fourier Transform Infrared Spectroscopy) are typical method for detecting DD%. However, these methods are both expensive and time-consuming.
In this study, we developed a rapid and low-cost method to detect DD% by UV-VIS spectroscopy. We found that Sunset yellow FCF (SY), Ponceau 4R (P4R) and Tartrazine can chelate with chitosan, and have absorbance change. Because SY absorbance change is higher than P4R and Tartrazine, we chose SY as our indicator. The result showed that SY absorbance change had positive correlation (R2=0.9718) with DD%. In addition, it is not influenced by Chitosan molecular weight. After method optimization, pH 4.0 20 mM Acetic buffer and 10 mg/L chitosan are the best for DD% determination.
Finally, We use 25 chitosan samples(MW=10-1000 kDa) to produce a calibration curve (R2=0.9417). Compared our mehod with 13C-NMR results to detect unknown DD% chitosan samples and their results had an error in less than 2 %, except for one sample which its yellow color had the effect on our detection. The process takes only 1 min and it has the potential for DD% rapid screening in the future.
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