CONCENTRATIONS OF VARIOUS ELEMENTS AND INORGANIC-IONS IN RICE STRAW AND ASH

Various elements and inorganic ions in rice straw and ash samples were analyzed by using inductively coupled plasma atomic emission spectrometry (ICP-AES) and ion chromatography (TC). Five major elements: Mg, Mn, Al, Ca, and Fe and eight minor and trace elements: Cr, Cu, Ti, Zn, La, Sr, Ba, and Bg were detected in these samples, at more than ppm-level. In ash samples the trace elements such as Y, As, V, Se, and Sc were also identified. The concentrations of SO4, PO4, Cl, Na, and K ions in these samples were higher than those of other ions measured. These elements and inorganic ion concentrations were approximately one order of magnitude higher in the ash than in the straw samples. Gas chromatography/mass spectrometry (GC/MS) and library search showed the presence of fatty-, carboxylic- and nicotinic acids, and their derivatives in small quantities in the straw samples.