Untreated or treated, 1 g of chitosan was put into a 330 mL vessel fully filled with bidistilled water containing dissolved oxygen (∼8–10 mg L−1) and hermetically plugged with an electrode sensitive to dissolved oxygen, which was registered by means of oxymeter Oxi level 2.Thesorbed (desorbed) amounts of oxygen were evaluated according tothe dissolved oxygen concentration change in wate