Determination of degree of substitution in succinic anhydride modified cellulose by headspace gas chromatography

This paper reports on a headspace gas chromatographic method (HS-GC) for rapid determination of degree of substitution in succinic anhydride (SA) modified celluloses. The method is based on the reaction between the carboxyl groups in SA modified cellulose and bicarbonate solution in a closed headspace sample vial. The CO2 released from the reaction was measured by HS-GC. The completion of the reaction was achieved within 25 min at 80 °C when a small sample size (<20 mg) was used. The relative standard deviation (RSD) measurement of precision was less than 4.1%, and the results were within 8.0% of those obtained with the traditional titration for determining the degree of substitution. The present method is simple, practical, automated, and suitable for use in anhydride modified cellulose research.