Molar mass distribution of lignins

Forss, K. Kokkonen, R. Sagfors, P.-E. Determination of the Molar Mass Distribution of Lignins by Gel Permeation Chromatography ACS Symp. Ser. 1989, this volume. 

Determination of the Molar Mass Distribution of Lignins by Gel Permeation Chromatography... 

A method is needed for the determination of the molar mass and molar mass distributions of lignins. The method should give reproducible results when used in different laboratories. The procedure should not be complicated, and the calibration components must be readily available and reasonably priced. 

It has been shown that the molar mass distributions of lignin sulfonates and kraft lignin can be determined by gel permeation chromatography. Calibration of the columns with lignin sulfonates of known molar mass or, alternatively, with commercially available proteins and polypeptides has been shown to give the same result. 

It should be noted that the broad molar mass distribution of fraction I in Figure 3 reflects the molar mass distribution of the lignin-carbohydrate compounds and not that of the lignin portion of the lignin-carbohydrate compounds. 

Figure 9. Molar mass distribution of pine kraft lignin (fractions 1-IV in Figure 8).

Bo, H. Turunen, E. Kokkonen, P. Molar mass and size distribution of lignins. In Handbook of Size Exclusion Chromatography and Related Techniques, Wu, C.-S., Ed. Chromatographic Science Series 91 Marcel Dekker, Inc. New York, 2004 355-383. 

Data concerning the elemental composition and methods for isolating lignin from the wood structure, as well as the mean molar masses and distributions of the obtained fragments, are given in Table II (1,5). 

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