13c Cp Mas Nmr Pectin Chitosan

The structures of acetylated and deacetylated monomers of chitosan are presented in fig.

13c cp mas nmr pectin chitosan. One could not expect to detect the da less than 10 in 15 n nmr and 13 c nmr techniques due to line broadening effects their high coefficient of variation 10. Nishioka sulfated derivatives of chitosan and their characterization with respect to biological activity chitin in nature and technology 10 1007 978 1 4613 2167 5 461 468 1986. 100 mg is dissolved in a known volume of aqueous hcl 0 010 mol l 1 and the solution is then ti trated with 0 1 mol l 1 naoh while the ph of the solution is measured at constant ionic strength 0 1 mol l 1 nacl. Cp mas 13 c nmr spectra of sclerotized insect cuticle and of chitin.

In this study the relaxation delay and contact time leading to quantitative chitin and deacetylated chitin 13 c cp mas nmr spectra have been determined. A new method utilizing 13c cp mas nmr spectra was developed for the simultaneous quantitative and structure analysis of pectin in tobacco. Chitin and chitosan were analyzed by x ray 13c cp mas nmr 13c ft chitin samples in a alpha form structure were isolated from beetle larva cuticle and silkworm bombyx mori pupa exuvia by treatment with 1 n hcl and 1 n naoh. Cp mas 13 c nmr and cp mas 15 n nmr are appropriate methods for insoluble chitin chitosan samples even the samples are associated with impurities and humidity ottøy et al 1996.

1h and 13c nmr spectra of chitosan allow a good characterization of the starting materials. A double air bearing probe and a zirconium oxide rotor were used. 2 presents the 400 mhz 1 h nmr spectrum of chitosan pcch00005 dda 87 at 70 c. The degree of acetylation of chitin and deacetylated chitin samples determined from the 13 c cp mas nmr spectra acquired with the optimised relaxation delay 5 s and contact time 1 ms is 0 68 and 0 16 respectively.

Table 1 shows the chemical shifts of chitosan protons in d 2 o dcl at 70 c. Chitosan was prepared by treating them in 40 naoh containing nabh 4. The assignment of chitosan peaks have already been reported in the literature. The polysaccharidic component of these hydrogels is chitosan while the novel cross linking agent is diethyl squarate des.

The conditions of acid extraction of tobacco samples and. The cp mas 13 c nmr spectra were recorded at 292 1 k on a bruker amx 300 instrument operating at 7 05 t. The solvent hod proton resonates at 4 67 ppm. Dd obtained by solid state 13 c nmr for low acetyl chitosan was not coincident with the.

Acquisition was performed with a standard cp pulse sequence using a 3 5 μs proton 90 pulse a 800 μs contact pulse and a 2 5 s. The mas rate was in the 4 5 khz range. In dried chitosan des networks. The graph with the variation of ph versus the.

Cp mas 13 c nmr heux et al.