Chemical Degradation Methods Permanganate Oxidation

The major drawback of the method is that only structures in lignin carrying free phenolic hydroxyl groups can be analyzed Therefore, the information obtained accounts for only a fraction of the total lignin structure However, in many cases, this information is sufficient to allow conclusions about the structure of a particular lignin Where such is not the case, alternative approaches are available to increase the number of free phenolic hydroxyl groups prior to analysis. 

In the original analytical method developed by Freudenberg and coworkers, wood was first subjected to alkaline hydrolysis at high temperature followed by a methylation with dimethyl sulfate The free phenolic hydroxyl groups were converted by this treatment to methoxyl groups and the phenolic units were thus stabilized toward oxidative breakdown The oxidation step was carried out by addition of portions of solid potassium permanganate at a pH at or near 7 until the purple color of the solution remained (Freudenberg et al 1936) 

The method of oxidative degradation using permanganate was later adopted by Miksche and co-workers In their comprehensive work, covering approximately a 10-year period, the methodology was greatly improved and modern spectroscopic methods were introduced Thus, it was found that the yield of 

Springer Series in Wood Science Methods in Lignin Chemistry (Edited by S Y Lin and C W Dence) 

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G Gellerstedt. Chemical degradation methods Permanganate oxidation. In SY Lin, CW Dence, eds. Methods in Lignin Chemistry. Berlin Heidelberg Springer-Verlag, 1992, pp. 322-333. 

Methods to remove trace organic compounds of all types from aqueous solution (J5, 16, 17) have been studied extensively. One was to deal with pesticide pollution of water supplies by using an oxidant for chemical degradation. Among the many chemical oxidants available, certain ones have shown that they reduce the concentration of organic contaminants—e.g., ozone, chlorine dioxide, chlorine, the peroxides, and potassium permanganate (iS, 19, 20, 21). 

Chemical methods of degradation include 1) reduction using metals, hydrogen, or metal hydrides 2) oxidation using copper oxide, permanganate, or chlorine and 3) alkaline... 

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