Determination of calcium, boron and impurities in colemanite by inductively coupled plasma-atomic emission spectrometry (ICP-AES)
Inductively coupled plasma atomic emission spectrometry (ICP-AES) has been used for the determination of the major elements (B and Ca) and the most significant impurities (Al, Fe, Mg, Si, and Sr) in colemanite (Ca2B6O11. 5H(2)O). Impurities were detected by X-ray fluorescence spectrometry. Samples were prepared by two decomposition methods (acid attack and fusion by sodium carbonate); no spectral interferences were observed except at the Al 396.152 nm line; preparation of standards of impurities by adding an equal amount of calcium (matrix matching) improved the results; Ca inter-element correction factor for B 208.959 nm line was alpha = 2.92x10(-3); the best detection limits (3 sigma criterion) were found for Al 396.125 nm, Fe 238.204 nm, Mg 279.553 nm, Si 251.611 nm, and Sr 407.771 nm lines. The procedure developed in this work can be applied to analyze other boron minerals too.