A simple spectrophotometric method was developed to quantify chitosan in the concentration range of 0.01 � 1%. The method is based on change in absorbance intensity of eosin due to alteration of the solution's pH with different concentrations of chitosan. The method is rapid, absorbance can be read between 30 minutes and 3 hours, but is dependent on the molecular weight and degree of acetylation of chitosan. The concentration-absorbance relationship is polynomial having R2 values of over 0.99, with the exception of high molecular weight chitosan in the concentration range 0.1 � 1% where R2 = 0.949, and water soluble chitosan in the concentration range 0.01 - 0.1% where R2 = 0.935. The method may have application in experiments where chitosan solutions are filtered or differently manipulated prior to, for example, analysis of antimicrobial properties, film formation, electrospinning, and encapsulation.

Determination of chitosan in aqueous solutions

240th National Meeting (2010)

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