Figure 3: NMR spectrum of OCM-CS. Peak for –CH2 at O-6 is intense compare to that present at O-3 and N-2. Abbreviations: OCM-CS, 6-O-carboxymethyl chitosan; C1–6, carbon atom of OCM-CS unit; C=O, carbonyl group; CH2, mehtylene group; O-3, O-6, oxygen present at the third and the sixth carbon of OCM-CS; N-2, nitrogen present at the second carbon atom of OCM-CS.