A novel method for rapid determination of alpha-cellulose content in dissolving pulps by visible spectroscopy

Abstract

A novel method has been developed for the rapid determination of the alpha-cellulose content in dissolving pulps. After alkaline treatment of the sample, the alkaline-soluble portion of the filtrate was transformed into colloids in a medium containing ethanol (80 %). The colloid solution was then measured by visible spectroscopy. The results showed a linear correlation between the root of absorbance at 500 nm and the amount of the colloid in the solution. The linear regression coefficient (R2) was 0.986 for eucalyptus pulp and 0.997 for pine pulp. A universal calibration model has been developed using the partial least square regression technique. The model is robust, and the results have good accuracy, with R2, root mean squared error cross validation, and relative prediction errors of 0.972, 0.492, and 0.51 %, respectively. The model also performed well when compared with the results from the traditional alpha-cellulose measurement method. In summary, the new method is simple, practical and suitable for use to determinate alpha-cellulose content in dissolving pulps in laboratory or industrial applications.