University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Geological -> mineral -> silicate

Citations 3

"Flow Analysis Of Silicate Rocks For Zirconium"
Talanta 1991 Volume 38, Issue 10 Pages 1119-1123
R. Kuroda, K. Oguma, K. Kitada and S. Kozuka

Abstract: A flow analysis system involving online configuration of an anion-exchange column has been examined to enrich and determine trace concentration of Zr of several ppm to hundred ppm levels in silicate rocks and minerals. About 100 mg of sample was decomposed by fusion with boric acid - Li2CO3 and taken up with 1 M HCl to 100 mL. A 1- or 4 mL portion of sample was introduced into an aqueous carrier stream, merged with H2SO4 and passed through a Bio-Rad AG1-X8 (100 to 200 mesh; Cl- form) column, eluted with HCl, color-developed with Arsenazo III and detected spectrophotometrically at 665 nm. Effects of foreign ions are tabulated.
Zirconium Spectrophotometry Sample preparation Column

"Determination Of Thorium And Uranium In Mineral Sands By Ion Chromatography"
J. Chromatogr. A 1994 Volume 671, Issue 1-2 Pages 181-191
P. E. Jackson*, J. Carnevale, H. Fuping and P. R. Haddad

Abstract: A number of sample dissolution and cleanup procedures were evaluated for the determination of U and Th in mineral sands. These included acid leaching and alkali fusion with peroxide, borate, carbonate, hydroxide and pyrosulfate fluxes, together with solvent extraction, cation exchange and selective complexation to remove matrix interference effects. The optimum sample preparation procedure involved tetraborate fusion and HNO3 leaching followed by either cation exchange pre-treatment or direct injection after dilution in α-hydroxyisobutyric acid (I). Ion chromatography was carried out on columns (30 cm x 3.9 mm i.d.) of Waters µBondapak C18, with 400 mM I/10% methanol of pH 4 as the mobile phase at a flow-rate of 1 ml/min, post-column derivatization with 0.13 mM Arsenazo III/10 mM urea/62 mM acetic acid and detection at 658 nm. The results agreed with those obtained by XRF and ICP-MS for ilmenite, synthetic rutile, zircon and rutile mineral sands with detection limits of 1 µg/ml for U and Th.
Thorium-232 Uranium Mass spectrometry HPLC Sample preparation Interferences

"Atomic Absorption Spectrophotometric Determination Of Magnesium In Silicates By Flow Injection Method"
Bunseki Kagaku 1986 Volume 35, Issue 8 Pages 690-693
Oguma, K.;Nara, T.;Kuroda, R.

Abstract: The powdered sample was fused with Li2CO3 and H3BO3 (in the ratio 1:3:3) and the product was dissolved in 1 M HCl. A portion of the solution was diluted with 1 M HCl until Mg concentration. was <2.5 ppm and was then injected into a flow injection system for blending with a solution containing 0.4% of La (to suppress interference from Al, phosphates and silicates) and injection into the air - acetylene (25:6) flame for AAS measurement of Mg at 285.2 nm. The coefficient of variation based on results from 16 reference materials was 0.77%.
Magnesium Sample preparation Spectrophotometry Interferences Reference material