Abstract
AbstractThe purpose of this research is to develop the optimized sample pretreatment for the determination of fly ash by spectrometric ICP instruments and to characterize the chemical composition of fly ash samples using a modified sequential extraction procedure. Experimental results indicate that an one-step high pressure bomb acid digestion (HNO3+H2O2+HF=3ml:5ml:2ml) on 190℃ for 5 hr should be the optimum pretreatment for determining multi-element by ICP-MS as well as ICP-AES. It shows that Al, Ca, Cr, Fe, K, Mg, Na, Pb, S and Zn can be determinated by ICP-AES and As, Ba, Cd, Cu, Mn, Ni, Sb, Se, Sr and V by ICP-MS. Accurate as well as precise analutical result has been generally obtained . The relative standard deviations for recoveries of most elements were within 10%. To further understand the influence of spectroscopic interference as well as chemical loss on the determinations of As and V, a standard addition experiment and the HR-ICP-MS measurement were performed. A sequential extraction experiment has also been performed to resolve the elements of fly ash into the following chemical forms: (1)soluble ; (2) exchangeable ; (3) carbonate ; (4) oxide ; (5) organic metal ; (6)silicate.