重铬酸钾氧化-连续流动法测定烟草中纤维素含量

Determination of Cellulose Content in Tobacco by Using Potassium Dichromate Oxidation-Continuous Flow Method

建立重铬酸钾氧化-连续流动法测定烟草中纤维素含量的方法,采用80%醋酸-硝酸混合液(80%醋酸∶硝酸=9.5∶0.5)除去试样中的半纤维素、木质素,纤维素在硫酸作用下被重铬酸钾氧化成二氧化碳和水,过量的重铬酸钾用连续流动分析仪测定。结果表明:采用醋酸-硝酸混合液能有效除去半纤维素、木质素的干扰,方法回收率为97.70%~99.49%,日内RSD为0.69%~1.61%,日间RSD为1.24%。说明该法可以应用于烟草中纤维素含量的测定。

We established the potassium dichromate oxidation-continuous flow method for the determination of cellulose content in tobacco. In this method,80% acetic acid-nitric acid mixed liquor（ 80% acetic acid ∶ nitric acid = 9.5 ∶ 0.5） was used to remove the hemicelluloses and lignin in tobacco samples; under the action of sulfuric acid,the cellulose was oxidized by potassium dichromate into carbon dioxide and water,and the excess potassium dichromate was determined by using continuous flow analyzer.The results showed that： using the acetic acid-nitric acid mixed liquor could effectively remove the hemicelluloses and lignin; the recovery rate by this method was 97. 70% ～ 99. 49%; the intraday RSD varied from 0. 69% to 1. 61%; the interday RSD was1.24%. So,this method can be used for the determination of cellulose content in tobacco.