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: Alloy -> silver

Citations 3

"Automated Method For The Selective Determination Of Gold By Online Solvent Extraction And Reversed Micellar-mediated Luminol Chemiluminescence Detection"
Microchem. J. 1994 Volume 49, Issue 2-3 Pages 183-193
Fujiwara T., Murayama K. and ImdadullahKumamaru T.

Abstract: A stream of aqueous Au solution (5 ml/min) was merged with a stream of CHCl3 containing tri-n-octylphosphine oxide (2 ml/min) and passed through a PTFE extraction column (3 m x 0.5 mm i.d.). The Au passed into the organic phase which was separated from the aqueous phase by a microporous PTFE membrane which was impermeable to water. Luminol reagent (sodium carbonate-buffered luminol solution of pH 11-8 in a reversed micellar bulk solvent of CHCl3/cyclohexane (6:5) containing 0.05 M hexadecyltrimethylammonium chloride) was sucked into a 100 µL loop and inserted into the CHCl3 carrier stream (2 ml/min). The reagent was mixed with the extract stream in a 70 µL coiled flow cell for chemiluminescence detection. Calibration graphs were linear for 10^-5000 ng/ml of Au with detection limits of 1 ng/ml. The RSD (n = 5) was 2.3% within the linear range. Interference effects of foreign ions are discussed. The method was applied to the determination of Au in Ag-alloys.
Gold Chemiluminescence Sample preparation Interferences Solvent extraction Teflon membrane Micelle

"Development Of New Hybrid Analytical Methods Based On The Combination Of Solvent Extraction With Reversed Micellar-mediated Chemiluminescence Detection And Their Application To The Trace Determination Of Precious Metals"
Bunseki Kagaku 1994 Volume 43, Issue 4 Pages 363-364

Abstract: A summary of the author's Ph.D. Thesis (Hiroshima Univ. 1993) is presented, which describes the study of the chemiluminescence reaction of tetrachloroaurate(III) with luminal in a reversed micellar system of hexadecylammonium chloride/H2O (buffered with Na2CO3)/CHCl3/hexane. Au(III) behavior was investigated by UV-visible spectrometry. Using a FIA system, the calibration graph was linear from 1-1000 pg/l and the detection limit was 10 fg/l of Au(III); the RSD was 3% for 20 pg/l of Au(III). A method based on the direct combination of solvent extract with the reversed micellar-chemiluminescence system was developed for the determination of Au in aqueous solution Interferences were eliminated by extraction with tri-n-octylphosphine oxide in CHCl3. The method was used to determine Au in Ag-based alloys. Catalysis of the system by Rh(III) was also evaluated.
Gold Chemiluminescence Sample preparation Interferences Solvent extraction Micelle

"Ionometric Determination Of Zinc In Alloys"
Zavod. Lab. 1996 Volume 62, Issue 8 Pages 16-17
Gur'ev, I.A.;Zyuzina, L.F.;Rusyaeva, Y.I.

Abstract: Alloy (3 g) was dissolved in 1:1 HNO3 and made up to 50 mL with water. A 1 mL portion of the solution was diluted with water to 100 mL. Then 10 mL of this solution was passed through a sorption column at 9 ml/min. The sorbed Zn was eluted with 5 mL 1 M KCl at 2 ml/min. A standard solution of zinc salt with a concentration of 6.6 mM, the eluate and a standard solution with a concentration of 6.6 mM were introduced consecutively into a FIA system with a chloride ISE based on tetradecylammonium chloride as indicator electrode for the ionometric determination of Zn. To analyze Ag solder, 1 g alloy was dissolved in 1:1 HNO3 and made up to 25 mL with water. A 3 mL portion of the solution was mixed with 1 mL 1 mM KCl. The sediment was filtered out and the filtrate and washing water were mixed with 30 mL 1 M KCl and made up to 100 mL with water. Of this 20 mL was passed through an ion-exchange column. The sorbed Zn ions were eluted with 5 mL 1 M KCl. Flow injection determination of Zn was carried out as above. The method was used to determine Zn in brasses and Ag solders. RSD did not exceed 6%. The detection limit was 2.2 mM Zn ions.
Zinc Ion exchange Electrode Indirect Column