STABILITY OF BIOGENIC SILICA EXTRACT OF JARAGUA GRASS (Hyparrhenia rufa) IN NaOH SOLUTION

摘要

STABILITY OF BIOGENIC SILICA EXTRACT OF JARAGUA GRASS (Hyparrhenia rufa) IN NaOH SOLUTION. Biogenic silica is used to describe compounds of hydrated silica (SiO2 center dot nH(2)O), with specific shapes and sizes, deposited in plants. The chemical composition of biogenic silica and its stability in Jaragua grass was studied in increasing concentration of NaOH. The analytical results demonstrated high concentration of Si, Al, Fe, Mg, P and low of Cu, Cd and Zn in the phytoliths composition. The silica bodies stability in NaOH solution with increasing concentration was different among the shapes and sizes. Silicified stomata and silicified plant tissues were dissolved along with the dumbbells because they are the less stable forms of biogenic silica.