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: Metal -> gold

Citations 3

"Determination Of Free Cyanide In Gold Cyanidation Process Liquors By Ion-interaction Chromatography With Post-column Derivatization"
J. Chromatogr. A 1991 Volume 550, Issue 1-2 Pages 559-571
Peter A. Fagan and Paul R. Haddad

Abstract: Leach liquor (10 µL) was applied to a column (15 cm x 4.6 mm) of Nova-Pak C18 with aqueous 25% acetonitrile in 5 mM low-UV PIC A as mobile phase (1 mL min-1). Cyano complexes of Cu(I), Fe(II), Ag(I), Fe(III) and Au(I) and thiocyanate were detected at 214 nm. Free CN- was detected in the void volume at 500 nm after online post-column reaction with N-chlorosuccinimide - succinimide and isonicotinic acid - barbituric acid. Three hardware configurations are described in the first of which the column eluate is passed directly to the post-column reactor. In the second system the eluate is passed to a valve allowing a selected portion of eluate to be passed to the post-column reactor. The third is the same as the second but with an ion-exclusion column (15 cm x 7.8 mm) inserted before the post-column reactor. Calibration graphs were rectilinear up to 300 ppm of free CN- by all three configurations. The coefficient of variation for determination of free CN- in leach liquor was 0.2%.
Cyanide, free HPIC Column Post-column derivatization

"Determination Of Arsenic In Gold By Flow Injection Inductively Coupled Plasma Mass Spectrometry With Matrix Removal By Reductive Precipitation"
Spectrochim. Acta B 1996 Volume 51, Issue 14 Pages 1823-1827
Paul Becotte-Haigha, Julian F. Tysona,*, Eric Denoyerb and Michael W. Hindsc

Abstract: Gold was dissolved in HCl/HNO3 (3:1) with heating until the volume had been reduced by half, then 1% HCl was added until the Au concentration was 0.05% (w/w), and a 40 g portion of this solution was treated with 20 mL each of 10% ascorbic acid/10% KI solution and HCl and diluted to 200 g. The precipitate was collected on glass wool and dissolved in aqua regia, and the solution was diluted to 200 mL. A 0.1 mL portion of this solution was diluted to 100 g, and a 0.5 mL portion was injected into a carrier stream of 10% HCl (10 ml/min) that then merged with a stream of NaBH4 solution in 0.05% (w/w) NaOH (5 ml/min). The gas-liquid separator was a slight modification of that described by Welz and Schubert-Jacobs (At. Spectrosc., 1991, 12, 91). The operating conditions of the ICP mass spectrometer are tabulated. For 29.7 µg/g of As found in gold the standard deviation (n = 4) was 0.972 µg/g; the results agreed with those obtained by GFAAS and by another ICP-MS method.
Arsenic Mass spectrometry Precipitation Method comparison Phase separator

"Determination Of Base Metals In Gold Bullion By Flow Injection Inductively Coupled Plasma Atomic-emission Spectrometry"
Can. J. Anal. Sci. Spectrosc. 1995 Volume 40, Issue 4 Pages 89-93
Hinds, M.W.;Valente, G.

Abstract: Gold bullion (250 mg) was heated gently with 5 mL HNO3 and the mixture was cooled. Portions (20 ml) of HCl were successively added and the solutions were heated and cooled until all the sample had dissolved. The cooled digest was diluted to 100 mL with HCl and a 500 µL portion was injected into a carrier stream of water (2.5 ml/min) of a flow injection system. The sample was carried to the nebulizer of the ICP and atomized (instrumental parameters given) and the absorbance of the atomized species were measured by AES at 324.754, 259.940, 231.604, 220.351 and 213.856 nm, respectively for base metals Cu, Fe, Ni, Pb and Zn. The corresponding detection limits were 0.7, 0.3, 0.5, 0.4 and 0.5 µg/ml (in solution) and 0.02, 0.04, 0.08, 0.01 and 0.02%, (% wt/wt) respectively, in the solid sample. Average recoveries were 97, 107, 98, 104 and 108%, respectively, for Cu, Fe, Ni, Pb and Zn with an RSD of 0.5-4%. The method was applied to the analysis of the base metals in two standard gold bullion samples. Results were in good agreement with those obtained by the fire assay method.
Metals, transition Copper Iron Nickel Lead Zinc Spectrophotometry Method comparison