ICP-AES ANALYSIS OF A RARE-EARTH ORE BY MEANS OF SPECTRAL FITTING

A spectral fitting method is described to analyze the ICP-AE spectrum of a crude rare-earth chloride obtained from a monazite ore. Each wind ow for a rare-earth element (width, 1 nm; 400 data) was successively a nalyzed using some developed software. The linear additivity of observ ed reference spectra of rare-earth elements in a spectrum database was assumed to synthesize a simulated spectrum, and differences between t he simulated spectrum and an observed spectrum were minimized by a lea st-squares method which varies linear coefficients. Consequently, dete rmined rare-earth elements (mass% of total rare-earth) were Y(0.42%), La(23.7%), Ce(45.5%), Pr(5.38%), Nd(19.8%), Sm(3.60%), Eu(0.011%), Gd( 1.17%), Tb(0.077%), Dy (0.26%), Ho(0.032%), Er(0.029%) and Yb(0.005%). Tm and Lu could not be determined due to weak line intensities. It to ok less than 2 min to analyze each window, when a personal computer eq uipped with an 80486 CPU was used. The obtained analytical results agr eed well with those obtained by isotachophoresis-particle induced X-ra y emission, confirming the utility of this method for such samples wit h heavy spectrum interference.