|Inglesby, Maria - FORMERLY USDA,ARS,WRRC|
Submitted to: Characterization of the Cellulosic Cell Wall
Publication Type: Book / Chapter
Publication Acceptance Date: August 25, 2004
Publication Date: May 12, 2006
Citation: Inglesby, M.K., Wood, D.F., Gray, G.M. 2006. Effect of chemical fractionation treatments on silicon dioxide content and distribution in oryza sativa. In: Characterization of the Cellulosic Cell Wall, D.D. Stokke and L.H. Groom, eds, Blackwell Publishing, Ames, IA, pp 192-212. Technical Abstract: In this study, rice straw and rice plant stems were subjected to nonconventional chemical fractionation methods to investigate the treatment of effects on the silica content of the straw as well as SiO2 content and distribution in rice stem tissue. The treatments included sodium hydroxide, an acid-catalyzed ethanol, and a hydrogen peroxide-catalyzed formic acid extraction. In addition, the Department of Energy, National Renewable Energy Laboratory, Golden, Colorado, performed four exploratory clean-fractionation experiments on the rice straw. Total and acid insoluble ash contents of all samples were determined by modified Tappi methods. The final acid-insoluble ash fractions were submitted for elemental analysis to establish the amounts present of silicon and of other inorganic constituents. The sodium hydroxide treatment reduced rice straw and stem silica contents to below 2% based on sample weights. For all other treatments it was shown that the silica remained with the solids fraction, as was evidenced by apparent SiO2 content increases. The localization of SiO2 in untreated and treated rice stem tissue was determined by energy dispersive X-ray (EDX). Two-dimensional elemental spatial distribution maps clearly showed the distinct localization of silicon in stem control samples. The formic acid treatment appeared to affect the silicon distribution in stem tissue. The use of FTIR as a rapid qualitative tool for the detection of SiO2 was explored.