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 -> barite

Citations 1

"Selective And Rapid Ion-chromatographic Determinations Of Alkaline-earth Metals And Applications To The Analysis Of Barite"
Fresenius J. Anal. Chem. 1989 Volume 335, Issue 7 Pages 687-691
Daren Yan, Jingan Zhang and Georg Schwedt

Abstract: Alkaline-earth metals, Pb and Cd were separated on a column (20 cm x 4 mm) of Nucleosil SA (10 µm) with 20 mM oxalic acid - 10 mM citric acid - 2 or 3 mM ethylenediamine, adjusted to pH 3.4, as mobile phase (1 mL min-1). A solution containing 1 mM 4-(2-pyridylazo)resorcinol, 0.5 mM ZnEDTA and 2 M NH3 (pH 11) was used for post-column derivatization (flow rate 0.33 mL min-1), with absorbance measurement at 495 nm and quantitation based on peak areas. Complete separation of the above metals, Cu, Zn, Fe and Mn required a mobile phase (0.9 mL min-1) of 2 mM oxalic acid - 3 mM ethylenediamine - 0.02% of NaCl (pH 2.8). To determine alkaline-earth metals in barite, 0.1 g of sample was fused with 5 g of Na2CO3 - K2CO3 (4:1) at 700°C for 30 min, the cooled melt was leached with hot water, and the ppt. was filtered off and dissolved in HCl. The resulting solution was diluted and filtered before analysis of a 0.1 mL portion (pH ~1.5). Detection limits ranged from 25 to 100 µg L-1 and recoveries were quantitative. At mg L-1 levels, coefficient of variation ranged from 0.7 to 1.6%.
Metals, alkaline earth HPIC Spectrophotometry Column Post-column derivatization Peak analysis Detection limit