FC法测定木素和纸浆中的酚羟基

Determination of the Content of Phenolic Hydroxyl Groups in Lignin and Pulp with FC-Method

应用FC法(Folin-Ciocalteu试剂法)测定了硫酸盐木素与H2O2反应前后酚羟基含量的变化,并测定了蒸煮、氧脱木素和H2O2漂白后不同纸浆中残余木素的酚羟基含量。测定结果表明,硫酸盐木素在与碱性H2O2反应后,酚羟基含量降低,高温H2O2反应后的下降程度更为明显;浆料残余木素中酚羟基含量随浆料卡伯值的降低而下降。

The FC-method using the reagents of Folin and Ciocalteu （FC） for the determination of the content of free phenolic hydroxyl groups in the lignin and the residual lignin in pulp is a simple and rapid method. In this paper, the FC-method was adopted to determine the change of the phenolic hydroxyl groups in the kraft lignin before and after the reaction with hydrogen peroxide. The phenolic hydroxyl groups in pulp samples with different kappa number after cooking, oxygen delignification and peroxide bleaching were also determined. The results showed that after the reaction with alkaline hydrogen peroxide, the content of phenolic hydroxyl groups in lignin goes down. The drop becomes more obvious under high temperature. The results from the pulp samples indicated that the phenolic hydroxyl group＇ s contents in the pulp decreases with the decrease of kappa number.