Fig 2. (a) 1H NMR spectrum of commercial chitosan sample S1 (10 mg i 1.96 ml D20/0.04 ml DCl) and (b) Variation in degree of acetylation of commercial chitosan samples as determined by NMR, as reported by supplier: (horizontal black line); range: (black corner); and (horizontal black line with corner arrow); greater than S1-S3: supplied by Sigma-Aldrich; T1-T3: supplied by Tahira Chemical Corp.).
