Determination Klason lignin

Determination of Lignin Content. Lignin content in plants (wood) is determined by direct or indirect methods (21). The direct method includes measurement of acid-insoluble (ie, Klason) lignin after digesting wood with 72% sulfuric acid to solubilize carbohydrates (22). The Klason lignin contents of representative lignifted materials are shown in Table 2. 

DF dietary fiber Cel cellulose Rha rhamnose Fuc fucose Ara arabinose Xyl xylose Man mannose Gal galactose Glu glucose U. ac. uronic acids KL Klason lignin n.d. not determined t traces Source Englyst and Cummings 1988 Englyst and others 1988 Marlett and Vollendorf 1994. 

Chemical and Spectroscopic Analyses. Acid insoluble lignin (Klason lignin) contents of wood species before and after extractions were determined using a modified procedure suitable for small samples (35). 

Yasuda and Terashima (11) recently showed that lignin under Klason lignin determination conditions afforded mefa-linked products. Vanillyl alcohol (4) yielded after reflux in 5% sulfuric acid, mefa-linked product (8) (Fig. 3). 

The solid phase was washed with water, dried at 40°C, and the yield and composition (xylan, arabinan, glucan, Klason lignin) were determined. 

Feedstock material and processed solids were analyzed for glucan, xylan, arabinan, and acetyl groups by quantitative acid hydrolysis according to standard methods (25). The acid-insoluble residue was considered as Klason lignin, after correction for the acid-insoluble ash (determined by igniting the contents at 575°C for 5 h). 

Determination of Acid-Insoluble (Klason) Lignin in Wood and Pulp... 

Pearl IA, Busche LR (1960) Studies on the chemistry of aspenwood XI The Klason lignin determination as applied to aspenwood with special reference to acid-soluble lignin Tappi 43 961-970... 

Srinivasa Rao Y, Shukla RN, Maheshwari S, Kulkarni AY, Jivendra Y (1983) Determination of permanganate and kappa number of pulp with high ash content. IPPTA 20(3) 55-56 Stewart CM, Foster OH, Cohen WE, Leslie RT, Watson AJ (1951) The selection and preparation of a reporducible wood sample for chemical studies. Appita 5 267- 311 Swan B (1965) Isolation of acid-soluble lignin from the Klason lignin determination. Sven Papperstidn 68 791-795... 

The Klason lignin content was determined by the TAPPI procedure (tf), and the ash content was determined at 750 °C. Viscosity determinations on a number of hemicellulose preparations indicated an average degree of polymerization of between 60 and 70 (7). 

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