Influences of Ash Correction on Simultaneous Determination of ADF and ADL in Tobacco by Van Soest Method

In order to determine the acid detergent fiber(ADF) and acid detergent lignin(ADL) in tobacco simultaneously, and taking account of that the ADF value inclusive of ash could be obtained during the ADL analyzing process of Van Soest method, the influences of ash correction on the measurement of ADF in tobacco samples of different types were investigated and the relationship between the residual silicate contents in ADF and ADL was studied. The results showed that: 1) The silicate content in ADF extremely significantly positively correlated to the ash content in samples and the silicate content in ADL. 2) For tobacco samples of high ash content, excluding flue-cured tobacco, the residual silicate would create bigger positive deviations in ADF determination. However, a relative deviation of less than 5% could be achieved via correcting the original measurement in said ADL analyzing. The analysis efficiency was improved remarkably by achieving the simultaneous determination of ADF and ADL dispensing with ADF ashing.