Degradation of chitosan in solution by gamma irradiation in the presence of hydrogen peroxide

摘要

Chitosan from squid pens with deacetylation degree (DD) of 70% and average molecular weight (M_(w0)) 90.5 x 10~3 in dilute lactic acid solution containing H2O2 (1%) was effectively degraded by irradiation with gamma ~(60)Co radiation (1.33 kGy/h) at doses in the range 4-16 kGy. Based on the results of M_w measured by gel permeation chromatography (GPC), it was concluded that there was particularly strong synergy between H2O2 and radiation for degradation at the lower radiation doses studied. Radiation scission yields (Gs) were found out to be 2.2 μmol/J and 0.2 μmol/J for 5% chitosan with and without 1% H2O2, respectively. The DD of degraded chitosan measured from IR spectra was almost unchanged by the treatment.