FIRST DERIVATIVE UV-SPECTROPHOTOMETRIC DETERMINATION OF THE DEGREE OF DEACETYLATION OF CHITOSAN

The degree of deacetylation of chitosan was determined directly by 1st derivative UV spectrophotometry using hydrochloric acid as solvent and N acetyl D glucosamine (ACGLSM) as standard. Good linearity between the values of 1st derivative (d A /d λ ) and concentrations of ACGLSM in the range of 0.0025~0.0400mg·ml -1 was obtained. The linear regression equation obtained was given as follows: d A /d λ =2.349 C +0.0008 ( r =0 9996). RSD′s found by analyzing 5 samples ( n =5 each) were in the range of 0.20% to 0.76%. Recoveries obtained from the analytical results of 5 samples were in the range of 99.8% to 101.4%. Under the analytical condition of this method, interferences from co existing substances, turbidities and colors were successfully removed. This method was proved to be simple, accurate and precise.