Table 1 . --Inorganic content of Cottonwood and the isolated 

 polysaccharide components 



Component 



Ash 



Ca 



K 



P 



Fe 



Na 









- Percent dry 



we%ght - 







Wood 



0.37 



0.059 



0.065 



.0122 



.0074 



.006 



Extracted wood 



.29 



.058 



.016 



.0006 



.0057 



.006 



Holocellulose 



1.02 



.020 



.001 



.0014 



.0032 



1 .394 



Cellulose 



.15 



.002 



.002 



.0003 



.0063 



.003 



Base-extracted xylan 



.15 



.001 



.001 



.0003 



.0060 



.070 



DMSO-extracted xylan 



.41 













^■Additions due to 



base extraction procedure. 









of the polysaccharides (holocellulose component) to the sugars indicated the presence 

 of cellulose, "xylan," and "mannan." These polysaccharides were isolated using the 

 procedure of Jones and others (1961). This gave 42 percent cellulose, 18 percent 

 4-0-methylglucuronoxylan, and 4.1 percent glucomannan based on original wood substance, 



Component 



Percent of 

 dry wood 



Percent of 

 extracted wood 



Benzene-alcohol (2:1) soluble 

 Alcohol soluble 



7.4 



Total extractives 



.2 



Klason lignin 6 



Cell wall polysaccharides 



31.9 

 76.1 



The holocellulose fraction was also extracted with dimethyl sulfoxide (DMSO) to 

 give a small yield of 0-acetyl -4-0-methylglucuronoxylan . This was used for the deter- 

 mination of acetyl groups, which are hydrolyzed under the alkaline condition of the 

 systematic fractionation. Analysis of this product showed 9.9 percent acetyl content. 



Hydrolysis of the "xylan" and analysis of the hydrolyzate showed the presence of 

 D-xylose and only a trace of D-glucose impurities. However, as usual, no 4-0-methyl- 

 D-glucuronic acid was detected. The presence of this component was ascertained through 

 methoxyl determination of 4-0-methylglucuronoxylan. This gave a value of 17.5 percent 

 for the uronic acid residue in the acetylated "xylan." On the basis of these data the 

 0-acetyl -4-0-methylgluronoxylan component contains an average of one uronic acid for 

 each seven D-xylose units and about half of the D-xylose units contain an acetyl group. 

 The glucomannan on hydrolysis provided D-glucose and D-mannose in the ratio of 1:1. 



The composition of inorganic materials found in the original wood as the ash 

 content and composition of these materials in the isolated cell wall polysaccharides as 

 impurities were analyzed as a part of this study. This analysis was carried out with 

 flame photometry for calcium, potassium, and sodium. Iron and phosphorus were deter- 

 mined by colorimetry following wet digestion. The data are presented in table 1 and 

 this information is used for determining the effect of inorganic materials on thermal 

 decomposition of wood and the effect on related cell wall polysaccharides. This infor- 

 mation will also allow comparison with other thermal analyses reported in the literature 



D Includes acid decomposition products. 



