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
Email: schalk@unf.edu
Website: @unf

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Geostandards Newsletter

  • Publisher: Wiley
  • FAD Code: GSNL
  • CODEN: GENEE7
  • ISSN: 0150-5505
  • Abbreviation: Geostand. Newsl.
  • DOI Prefix: 10.1111/j.1751-908X
  • Other Name(s): The Journal of Geostandards and Geoanalysis, Geostandards and Geoanalytical Research
  • Language: English
  • Comments: Fulltext from 1977 V1

Citations 9

"Use Of Chelating Resin YPA4 Micro-columns For The On-line Preconcentration And Separation Of Gold(III), Silver(I), Palladium(II) And Platinum(IV) In Geological And Environmental Samples And Their Determination By Inductively Coupled Plasma-atomic Emission"
Geostand. Newsl. 2004 Volume 28, Issue 3 Pages 383-390
Yiwei Wu, Zucheng Jiang and Bin Hu

Abstract: A simple and selective method of flow injection (FI) using a micro-column packed with chelating resin YPA4 as solid phase extractant was developed for the pre-concentration and separation of trace amount of noble metals, Au(III), Ag(I), Pd(II) and Pt(IV), followed by ICP-AES determination. In HNO3 media, the chelating resin was selective towards Au(III), Ag(I), Pd(II) and Pt(IV), and the analyzed ions were readily desorbed quantitatively with 5 mL of 2.5% (m/v) thiourea. Effects of acidity, sample flow rate and concentration, elution solution and interfering ions on the recovery of the analytes were systematically investigated. Under optimum conditions, the adsorption capacities of YPA4 for Au(III), Ag(I), Pd(II) and Pt(IV) were 67.2, 43.1, 64.8 and 27.6 mg per gram of resin in HNO3 media, respectively. It was found that YPA4 could be used for more than eight runs in HNO3 media without loss of capacity. The proposed method was used for the determination of trace noble metals in geological and environmental samples, and the analytical results obtained were in good agreement with the recommended values.

"Off-line And On-line Determination Of Eleven Rare Earth Elements In Silicate Rocks By ICP-AES Using Dowex Minicolumns For Separation Of Interfering Elements In Continuous Flow Systems"
Geostand. Newsl. 2002 Volume 26, Issue 1 Pages 63-73
Geraldo R. Boaventura, Robson C. De Oliveira and Ricardo E. Santelli

Abstract: The methodologies developed in this work comprise ion-exchange separation of interfering elements from rare earth elements (Fe, Al and Ca), by using resin minicolumns (Dowex-50W-X8 200-400 mesh) for the determination of La, Ce, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb and Lu by inductively coupled plasma-atomic emission spectrometry, using both off-line and on-line continuous flow systems. These methods can be used to determine rare earth elements in common silicate rocks, such as granite, basalt, rhyolite and andesite. Thirteen geochemical reference materials were used to evaluate the accuracy and precision of the off-line and on-line methods. Chondrite-normalized diagrams were obtained and compared to values reported in the literature. When compared to conventional procedures, the proposed methods provide fast and low cost rare earth elements determinations in the analysis of silicate rocks. Eighteen samples per hour could be analyzed by the proposed method using the automated procedure for the determination of the eleven rare earth elements.
Preconcentration

"Determination Of Chromium, Nickel, Copper And Zinc In Milligram Samples Of Geological Materials Using Isotope Dilution High Resolution Inductively Coupled Plasma-mass Spectrometry"
Geostand. Newsl. 2002 Volume 26, Issue 1 Pages 41-51
Akio Makishima, Katsura Kobayashi and Eizo Nakamura*

Abstract: A simple and accurate method for the determination of Cr, Ni, Cu and Zn at ?g g-1 levels in milligram-sized bulk silicate materials is reported using isotope dilution high-resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS) with a flow injection system. Silicate samples with Cr, Ni, Cu and Zn spikes were digested with HF-HBr and Br2, and subsequently decomposed at 518 K in a Teflon bomb. In this procedure, all sulfides and chromite, major hosts of these elements, were completely decomposed, thus allowing for isotope equilibration between the sample and spike. Magnesium and Al fluorides formed after the digestion of the sample were removed by centrifugation, and the supernatant was directly aspirated into a HR-ICP-MS at a mass resolution of 7500, where interfering oxide ions, ArO +, CaO+, TiO+, CrO+ and VO +, were separated from Cr+, Ni+, Cu+ and Zn+. No matrix effects were observed down to a dilution factor of 50. Detection limits for these elements in silicate samples were < 0.04 ?g g-1. The effectiveness of the technique was demonstrated by the analysis of 13 to 40 mg test portions of USGS and GSJ silicate reference materials with a major element composition ranging from andesite to peridotite, in addition to 8-23 mg of the Smithsonian reference Allende. Both the reproducibility and the deviation from the reference value for most reference materials of various rock types were < 9%, and thus confirm that the method gives accurate analytical results for small sample sizes over a wide range of Cr, Ni, Cu and Zn contents. This method is, therefore, suitable for analyzing small and/or precious bulk samples, such as meteorites, mantle peridotites and mineral separates, and for the characterisation of silicate and sulfide minerals for use as calibration samples in secondary ion mass spectrometry or laser ablation ICP-MS.

"Determination Of Selenium Concentration In Sixty Five Reference Materials For Geochemical Analysis By GFAAS After Separation With Thiol Cotton"
Geostand. Newsl. 2001 Volume 25, Issue 2-3 Pages 317-324
Marin, L.;Lhomme, J.;Carignan, J.

Abstract: Selenium has been determined in sixty five geological reference materials of different origins by graphite furnace atomic absorption spectrometry Samples were decomposed with a mixture of nitric and hydrofluoric acids. Selenium was reduced to Se-IV with hydrochloric acid, and then fixed and separated from the matrix on thiol cotton. After digestion of the thiol cotton in hot nitric acid, the Se concentration was measured using palladium and magnesium nitrates as a matrix modifier. The limit of determination was 0.02 µg g-1, the precision of the results (relative standard deviation of 3 to 8 replicates) varied from 2.6 to 17.7% with an average of 7.9% in the range 0.02-42.7 µg g-1 and was similar to the value obtained for synthetic samples. Our results are in good agreement with available literature values.

"Routine Analyses Of Trace Elements In Geological Samples Using Flow Injection And Low Pressure On-line Liquid Chromatography Coupled To ICP-MS: A Study Of Geochemical Reference Materials BR, DR-N, UB-N, AN-G And GH"
Geostand. Newsl. 2001 Volume 25, Issue 2-3 Pages 187-198
Jean Carignan, Pascal Hild, Guy Mevelle, Jacques Morel and Delphine Yeghicheyan

Abstract: We describe analytical procedures for trace element determinations developed at the CNRS Service d'Analyse des Roches et des Mine?raux (SARM) and report results obtained for five geochemical reference materials: basalt BR, diorite DR-N, serpentinite UB-N, anorthosite AN-G and granite GH. Results for rare earth elements, U and Th are also reported for other reference materials including dunite DTS-1, peridotite PCC-1 and basalt BIR-1. All rocks were decomposed using alkali fusion. Analyses were done by flow injection ICP-MS and by on-line low pressure liquid chromatography (LC)-ICP-MS for samples containing very low REE, U and Th concentrations. This latter method yielded limits of determination much lower than data by direct introduction and eliminated possible isobaric interference on these elements. Although results agree with most of the working values, when available, results for some elements differed slightly from the recommended concentrations. In these cases, we propose new values for Co, Y and Zn in basalt BR, Zr in diorite DR-N, Sr and U in granite GH, and Ga and Y in anorthosite AN-G. Furthermore, although the Sb concentration measured in AN-G was very close to our limit of determination, our value (0.3 ± 0.1 ?g g-1) is much lower than the reported working value of 1.4 ± 0.2 ?g g-1. These new values would need to be confirmed by a new inter-laboratory program to further characterise these reference materials. Results obtained for REE, Th and U concentrations using the on-line low pressure LC-ICP-MS yielded good limits of determination (ng g-1 to sub ng g-1 for rocks and ng L-1 to sub ng L-1 for natural waters) and accurate results. The efficiency of the matrix separation allowed accurate measurements of Eu without the need to correct the BaO isobaric interference for samples having Ba/Eu ratios as high as 27700. For REE concentrations in PCC-1 and DTS-1, differences with values reported in the literature are interpreted as resulting from possible heterogeneity of the reference materials. Thorium and U values are proposed for these two samples, as well as for AN-G and UB-N. Copyright © Association Scientifique pour la Ge?ologie et ses Applications.

"Techniques For The Determination Of Cyanide In A Process Environment: A Review"
Geostand. Newsl. 2000 Volume 24, Issue 2 Pages 183-195
Deon E. Barnes, Peter J. Wright, Sandra M. Graham and Elaine A. Jones-Watson

Abstract: The determination of cyanide in various forms is important for industrial processes as well as for environmental investigations and monitoring associated with these processes. The accurate determination of cyanide is difficult for various reasons. Depending on the pH of the solution, cyanide is present both in molecular form (HCN) and ionic form (CN-). Furthermore, cyanide is a good complexing reagent and reacts with almost all cations resulting in complexes with widely varying properties, such as stabilities, solubilities and rates of reaction. Cyanide also breaks down in sunlight. and air, so that sampling and sample treatment become very important aspects to consider in the methodologies. During the last fifty years the determination of cyanide has been approached from various angles and a myriad of methods has been developed for its determination. This study represents a survey of methods commonly used in industrial laboratories for the analysis of cyanide-containing solutions. An overview of the nomenclature often used for the various forms of cyanides is discussed and the values resulting from a particular analysis will be interpreted. Most common interferences in samples originating from gold processing plants will be discussed.

"Determination Of Selenium In Fifty Two Geochemical Reference Materials By Hydride Generation Atomic Absorption Spectrometry"
Geostand. Newsl. 2000 Volume 24, Issue 1 Pages 83-86
Shigeru Terashima and Noboru Imai

Abstract: The selenium content of fifty two geochemical reference samples, issued by several reference material producers (ANRT, GIT-IWG, USGS, NIST and GSJ) has been determined by continuous hydride generation and atomic absorption spectrometry. Selenium(VI) in the digested solutions was prereduced to selenium(UV) by heating in 6 mol L-1 HCl solution. The limit of detection was 3 ng g-1 selenium in common geological samples. Some samples which contain a large amount of heavy metals were analyzed by the standard addition technique. The agreement between the reported results and published data is satisfactory.

"Determination Of Molybdenum, Antimony And Tungsten At Sub Mu G G (super -1) Levels In Geological Materials By ID-FI-ICP-MS"
Geostand. Newsl. 1999 Volume 23, Issue 2 Pages 137-148
Akio Makishima and Eizo Nakamura

Abstract: We have developed a rapid and accurate method for the determination of Mo, Sb and W in geological samples using isotope dilution inductively coupled plasma-mass spectrometry with a flow injection system (ID-FI-ICP-MS). The chemical procedure requires HF digestion of the sample with a Mo-Sb-W mixed spike, subsequent evaporation and dissolution of Mo, Sb and W from Mg and Ca fluorides with HF. Recovery yields of Mo, Sb and W in the extraction were > 94% for samples of peridotite, basalt and andesite composition, with the exception of W in samples of peridotite composition for which recovery was 81%. No matrix effects were observed in the determination of the isotope ratios of Mo, Sb and W in solutions prepared from peridotite, basalt and andesite samples down to a dilution factor of 100. Detection limits of Mo, Sb and W in silicate materials were at the several ng g-1 level. Analysis of the silicate reference materials PCC-1, DTS-1, BCR-I, BHVO-1, AGV-1 from the US Geological Survey and JP-1, JB-1, -2, -3, JA-1, -2, and -3 from the Geological Survey of Japan as well as the Smithsonian reference Allende powder yielded reliable Mo, Sb and W concentrations. The repeatability in the analysis of basalts and andesites was < 9%. This technique requires only 0.2 mL sample solution, and is therefore suitable for analyzing small and/or precious samples such as meteorites, mantle peridotites and their mineral separates.
Dilution

"Determination Of Zirconium, Niobium, Hafnium And Tantalum At Ng G (super -1) Levels In Geological Materials By Direct Nebulisation Of Sample HF Solution Into FI-ICP-MS"
Geostand. Newsl. 1999 Volume 23, Issue 1 Pages 7-20
Akio Makishima, Eizo Nakamura* and Toshio Nakano

Abstract: We have developed a rapid and accurate method to determine Zr, Nb, Hf and Ta (denoted as HFSE) in geological samples by inductively coupled plasma-mass spectrometry fitted with a flow injection system (FI-ICP-MS). The method involves sample decomposition by HF followed by HF dissolution of HFSE coprecipitated with insoluble Mg and Ca fluoride residues formed during the initial HF attack. This HF solution was directly nebulized into an ICP mass spectrometer. An external calibration curve method and an isotope dilution method (ID) were applied for the determination of Nb and Ta, and of Zr and Hf, respectively. Recovery yields of HFSE were, 96% for peridotite, basalt and andesite compositions, apart from Zr and Hf for peridotite (, 85%). No matrix effects for either signal intensities of HFSE or isotope ratios of Zr and Hf were observed in basalt, andesite and peridotite solutions down to a dilution factor of 100. Detection limits in silicate rocks were 40, 2, 1 and 0.1 ng g-1 for Zr, Nb, Hf and Ta, respectively. This technique required only 0.1 mi of sample solution, and thus is suitable for analyzing small and/or precious samples such as meteorites, mantle peridotites and their mineral separates. We also present newly determined data for the Zr, Nb, Hf and Ta concentrations in USGS silicate reference materials DTS-1, PCC-1, BCR-1, BHVO-1 and AGV-I, GSJ reference materials JB-1, -2, -3, JA-1, -2 and -3, and the Smithsonian reference Allende powder.