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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Coal

Classification: Geological -> rock -> coal

Citations 10

"Determination Of Arsenic And Selenium In Coal By Continuous-flow Hydride-generation Atomic Absorption Spectrometry And Atomic Fluorescence Spectrometry"
Anal. Chim. Acta 1987 Volume 194, Issue 1 Pages 177-187
Les Ebdon and John R. Wilkinson

Abstract: Powdered coal (0.7 g) was digested with 72% HClO4 with cautious heating (and quenching in iced water if ignition appeared imminent) until all carbonaceous material had dissolved and was then heated under reflux for a further 10 min. After cooling, the solution was transferred, with washing with 5 M HCl, to a 50 mL flask. In order to remove interfering metal ions, portions (10 to 20 ml) of the digest were transferred to a PTFE centrifuge tube and 2 mL of 10% LaCl3 solution was added followed by 1 mL of either 10% NaI solution (for As) or 10% NaBr solution (for Se). The mixture was cooled, centrifuged, and treated with further 10% LaCl3 solution, the supernatant solution was discarded and the ppt. was dissolved in 5 M HCl and diluted to volume Hydride-generation AAS or AFS was used to determine As or Se; the AFS detection limit was 25 or 10 ng g-1, respectively.
Arsenic Selenium Fluorescence Spectrophotometry Interferences

"Flow Injection Spectrofluorimetric Determination Of Sulfate Using Calcein And Zirconium"
Anal. Chim. Acta 1994 Volume 298, Issue 3 Pages 401-404
N. Chimpalee, D. Chimpalee, S. Suparuknari, B. Boonyanitchayakul and D. Thorburn Burns

Abstract: Sulphate can be determined spectrofluorimetrically (lambdaem = 505 nm, lambdaex = 410 nm) based on the formation of a ternary complex between sulphate, zirconium and calcein in a flow-injection system. The carrier stream was deionised water and the reagent streams were 100 µg mL-1 Zr (as ZrOCl2) in 1% (v/v) hydrochloric acid, and 40 µg mL-1 calcein in 0.1 M potassium hydroxide. The injection rate was 50 h-1. The calibration graph was linear up to 25 µg mL-1 SO2-4 based on 250 µL injection volumes. The relative standard deviation (n = 10) was 1.95% for 10 µg mL-1 SO2-4; the detection limit was 0.82 µg mL-1 SO2-4. The system has been applied to the determination of sulphur in NIST coal samples after oxygen bomb combustion.
Sulfate Fluorescence Indirect

"Direct Determination Of Beryllium In Coal Slurries Using Graphite Furnace Atomic Absorption Spectrometry With Automatic Injection"
Analyst 1989 Volume 114, Issue 10 Pages 1331-1333
Lana Haraldsen and M. A. Bruno Pougnet

Abstract: A Perkin-Elmer autosampler (AS-40) was modified by incorporating magnetic stirring of the samples for the analysis of slurries. Platform atomisation and matrix modification were used for the determination of beryllium in three South African Reference Material coals SARMs 18, 19 and 20. The good precision and accuracy of the procedure are illustrated by the results obtained for the SARM samples.
Beryllium Spectrophotometry Automation Slurry

"Flow Injection Systems For Directly Coupling Online Digestions With Analytical Atomic Spectrometry. 2. Reactions In A Microwave Field"
J. Anal. At. Spectrom. 1993 Volume 8, Issue 5 Pages 697-704
Thomas J. Gluodenis Jr. and Julian F. Tyson

Abstract: A stopped-flow pressure heater mounted within a microwave oven was used for sample digestion for flame AAS or ICP-AES. The pressure transducer (2.0 in. x 2.75 in. diameter) was made from stainless-steel and PTFE components and operated at 400 lb/in. for 5 min, test samples being digested in HNO3. The sample preparation was compared with two conventional procedures involving hotplate digestion, dry-ashing, slurry preparation and microwave digestion with use of three reference materials, and results showed no significant difference except that low recoveries were obtained from a coal sample, due possibly to incomplete dissolution of silicates. (For Part I see Anal. Abstr., 1993, 55, 2H233).
Silicate Sample preparation Sample preparation Spectrophotometry Spectrophotometry Microwave Online digestion Method comparison Stopped-flow Reference material Slurry

"Slurry Injection Atomic Absorption Spectrometry For Analysis Of Whole Coal"
Anal. Chem. 1979 Volume 51, Issue 12 Pages 1905-1915
James E. O'Reilly and Donald G. Hicks

Abstract: A method is described which permits the determination of a wide variety of major-, minor-, and trace-level elements directly in powdered whole coal by aspiration of aqueous slurries into a conventional atomic absorption spectrophotometer. Relative precisions and accuracies are in the range of ±1-5% and 5-25%, respectively. The relative atomization efficiencies of almost every element studied are remarkably constant; an element in a coal matrix will produce an absorption signal 20±6% that of a purely aqueous solution of equivalent concentration. The details of sample preparation, the most critical aspect of the entire procedure, and which must be carefully and reproducibly performed, are given. Considerable savings in operator and turnaround times over normal ashing-acid dissolution procedures can be achieved.
Copper Chromium Iron Nickel Strontium Zinc Spectrophotometry Slurry

"Determination Of Thallium In Minerals And Coal By AAS And ICP-AES"
Fresenius J. Anal. Chem. 1981 Volume 306, Issue 5 Pages 385-393
H. Berndt, J. Messerschmidt, F. Alt und D. Sommer

Abstract: A procedure is described for the determination of Tl in mineral materials and coal after pre-concentration. After dissolution of the sample, the Tl is complexed with dithio-phosphorus acid-O,O-diethylester, ammonium salt, and the complex is adsorbed onto an activated carbon filter. This complexing agent renders it possible to separate the Tl even from strongly acid solutions - and also when Fe is present - up to 90%. By treating the activated carbon with nitric acid a trace concentrate is obtained practically free of matrices (separation factor > 103), from which the Tl can then be determined without interferences by various spectroscopical methods. When applying ICP/AES (inductively coupled plasma/atomic emission spectrometry) a detection limit of 2 g/g is obtained; with the usual method of flame-AAS the detection limit is 0.4 g/g. With the more sensitive graphite furnace technique and the new platinum loop method of flame-AAS, a detection limit of 0.01 g/g is reached in respect of each of these procedures. By making use of a transient recorder additional information concerning the temporal vaporization behavior of Tl from the sample matrix can be gained.
Thallium Spectrophotometry Spectrophotometry Spectrophotometry Carbon filter Preconcentration

"Effect Of Slurry Mineralogy On Slurry ICP-AES"
Fresenius J. Anal. Chem. 1996 Volume 355, Issue 7-8 Pages 801-802
C. J. Walker, D. E. Davey, K. E. Turner Contact Information and I. C. Hamilton

Abstract: A sample (0.01-2 g) was ground with 20 mL water in a micronizing mill using sintered corundum rods. After dilution with water to 100 ml, the slurries were sonicated for 10 min and analyzed by FIA ICP-MS (Dickinson et al., BHP Research, Central Research Laboratories, 1990, CRL/S/18/90). The background noise was reduced by increasing grinding time, e.g., the peak area RSD for Cu in pyrite was reduced from 17% to 3% by increasing grinding time from 15 to 30 min. Sphalerite, pyrite, haematite, pyrrhotite, goethite and two types of coal slurries containing 2-176 mg/l Fe had the same linear calibration graph of Fe content vs. peak area; results were not affected by the slurry density or mineral hardness or density. The determination of Zn in ZnO, ZnS, sphalerite, pyrite and pyrrhotite was also unaffected by slurry mineralogy.
Copper Mass spectrometry Sample preparation Spectrophotometry Slurry

"Determination Of Arsenic And Selenium In Coal And Fly Ash By Continuous-flow Hydride-generation ICP-AES"
Bunseki Kagaku 1987 Volume 36, Issue 9 Pages T95-T99
Etoh, M.

Abstract: Coal was digested with HNO4 and HClO3 and fly ash was digested with HNO3 and H2SO4. The As and Se were separated from co-existing elements (except for Sb, Sn and Ge) by distillation with HBr and Br. Arsenic and Se were determined by continuous-flow hydride-generation ICP-AES. Recoveries were 98 to 104%, and coefficient of variation were 2.4 to 3.5 and 2.7 to 4.5%, respectively, for As and Se. Tin, Sb and Ge did not interfere at concentration. present in the samples used.
Arsenic Selenium Sample preparation Spectrophotometry Interferences

"Determination Of Pyritic Sulfur In Coal Or Iron(III) In Aqueous Solutions By Flow Injection Analysis"
J. Coal Qual. 1985 Volume 4, Issue 1 Pages 68-71
Whitaker, M.J.; Bryant, M.F.

Abstract: The simple automated method described for determining pyritic S involves initial acid digestion of the sample to oxidize pyritic Fe to Fe(III), and use of NH4SCN solution as the carrier stream and color reagent for Fe(III). About 60 samples can be analyzed in 1 h for 5 to 150 ppm of Fe(III) (0.05 to 1.7% of pyritic S for 1-g samples); the coefficient of variation is <1%. A computer capable of collecting several signals simultaneously is used in conjunction with software by which data are plotted, sample peak-height values can be edited, and laboratory reports are prepared.
Sulfur Iron(III) Sample preparation Spectrophotometry Computer

"Advances In Online Particulate Composition Analysis"
Powder Technol. 1992 Volume 69, Issue 1 Pages 93-99
Harrison R. Cooper

Abstract: A review is presented, with 32 references, of techniques including X-ray diffraction, XRF, prompt NAA, magnetic resonance methods and flow injection spectrophotometry in online analysis of bulk powdered solids, e.g., ores and coals. Measurements required to define properties of particulate materials include size, composition and density among the important variables. In managing a particulate-related process, one or more of these variables would be significant to defining control parameters for materials being treated in the process. Therefore, inspection methods for size, composition and density are of particular interest. Advances in methods employed for inspection are reviewed from the standpoint of establishing particulate composition data. Principle attention is given to on-line automated procedures adaptable for use with controls.
Spectrophotometry Review