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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Coal Fly ash

Classification: Geological -> rock -> coal -> fly ash

Citations 9

"Determination Of Cadmium, Copper And Lead In Environmental Samples. An Evaluation Of Flow Injection Online Sorbent Extraction For Flame Atomic Absorption Spectrometry"
Anal. Chim. Acta 1994 Volume 285, Issue 1 Pages 33-43
Renli Ma, Willy Van Mol and Freddy Adams*

Abstract: Lake, estuarine or river sediment, calcareous loam soil or coal fly ash were digested in a PTFE bomb with concentrated HF and HNO3 by heating until fuming. After cooling HClO4 was added, the bomb was sealed and heated for 8 h at 150°C. Silicates were removed by repeated addition of HF and HNO3 and evaporation to dryness and the residue was dissolved in HNO3, HCl and water. The solution was injected into a FIA system and mixed with 0.2% ammonium diethyldithiophosphate in 0.1 M citric acid adjusted to pH 1 with HNO3. Following pH dependent complexion with 0.1% diethylammonium-NN-diethyldithiocarbamate in 0.1 M acetic acid (described), 50 mM citric acid was added to mask Fe(III) and Mn(II). The complexes were sorbed onto C18 bonded silica gel (40-63 µm) in a conical extraction column, eluted with methanol and analyzed by AAS; elution rates and AAS nebulizer uptake rates are discussed. Calibration graphs of peak height were linear up to 50 µg/l of Cd, 300 µg/l of Cu and 1 mg/l of Pb with detection limits of 0.8, 1.4 and 10 µg/l, respectively, with a 20 s sample loading at 8.7 ml/min.
Cadmium Copper Lead Sample preparation Spectrophotometry Sample preparation Silica gel C18 Precipitation Solid phase extraction

"Determination Of Hexavalent Chromium In Industrial Hygiene Samples Using Ultrasonic Extraction And Flow Injection Analysis"
Analyst 1997 Volume 122, Issue 11 Pages 1307-1312
Jin Wang, Kevin Ashley, Eugene R. Kennedy and Charles Neumeister

Abstract: A simple, fast, and sensitive method was developed for the determination of hexavalent chromium (Cr(VI)) in workplace samples. Ultrasonic extraction in alkaline solutions with 0.05 M (NH4)2SO4-0.05 M NH3 provided good extraction efficiency of Cr(VI) from the sample and allowed the retention of Cr(VI) on an ion-exchange resin (95%). The Cr(VI) in the sample solution was then separated as an anion from trivalent chromium [Cr(III)] and other cations by elution from the anion-exchange resin with 0.5 M (NH4)2SO4 in 0.1 M NH3 (pH 8) buffer solution. The eluate was then acidified with hydrochloric acid and complexed with 1,5-diphenylcarbazide reagent prior to flow injection analysis. By analyzing samples with and without oxidation of Cr(III) to Cr(VI) using Ce(IV), the method can measure Cr(VI) and total Cr. For optimizing the separation and determination procedure, preliminary trials conducted with two certified reference materials (CRMs 013-050 and NIST 1633a) and three spiked samples (ammonia buffer solution, cellulose ester filters and acid washed sand) indicated that the recovery of Cr(VI) was quantitative (> 90%) with this method. The limit of detection for FIA-UV/VIS determination of the Cr-diphenylcarbazone complex was in the sub-nanogram range (0.11 ng). The technique was also applied successfully to a workplace coal fly ash sample that was collected from a power plant and paint chips that were collected from a heating gas pipe and a university building. The principal advantages of this method are its simplicity, sensitivity, speed and potential portability for field analysis.
Chromium(VI) Chromium(III) Sample preparation Spectrophotometry Reference material Speciation

"Certification Of A New NIST Fly Ash Standard Reference Material"
Fresenius J. Anal. Chem. 1995 Volume 352, Issue 1-2 Pages 193-196
Robert R. Greenberg, Jean S. Kane and Thomas E. Gills

Abstract: A new fly ash standard reference material was prepared from the burning of mixed Appalachian range coals in a single coal-fired power plant. The material was certified by a number of different analytical methods including isotope-dilution MS, NAA, XRF, ICP-AES, ETAAS, cold vapor AAS, flow injection AAS and flame emission spectrometry. The homogeneity of the sample was determined by NAA and XRF. Results are discussed.
Mercury Spectrophotometry Spectrophotometry Reference material

"Flow Injection Method For The Separation Of Thallium And Gold On A Sephadex Column And Their Extraction-photometric Determination With Rhodamine B"
Anal. Sci. 1990 Volume 6, Issue 3 Pages 421-424

Abstract: The method involves injection of a sample into 0.5 M HCl - 1 M LiCl as carrier solution (0.6 mL min-1), and passsage through a column (15 cm x 3 mm) of Sephadex G-25. The eluate is added to 0.04% rhodamine B (0.18 mL min-1), and the mixture is then mixed with benzene (0.2 mL min-1). After passage through a 2-m extraction coil and a phase separator, the absorbance of the organic phase is measured at 565 nm. The retention times for Tl and Au on the column are 5.5 and 11 min, respectively. From 0 to 5 mg L-1 of each metal can be determined. The method was applied to coal fly ash and ores. Recoveries were 97 to 98% for Tl and Au in the respective samples.
Thallium Gold Spectrophotometry Sample preparation Column Phase separator Organic phase detection Sephadex Solvent extraction Reference material

"Online Preconcentration Of Rare-earth Element By FIA-ICP-AES"
Anal. Sci. 1997 Volume 13, Issue suppl Pages 27-30

Abstract: A mini-column filled with Dowex 50x8 resin is developed and investigated for the analysis of trace level of rare earth element by ICP-AES. The column is installed between peristaltic pump and ICP-AES, and ng/ml level of rare earth element is analyzed directly by online FTA-ICP-AES. 6N hydrochloric acid is found to be an optimum concentration for stripping, and the optimum flow rates for loading and stripping are measured at 0.8 and 1.1 ml./min, respectively. Easily ionized elements from flux such as Na and K would be eliminated easily by 2N hydrochloric acid before stripping the rare earth element deposited on the resin. For an analysis of Sm, the absolute detection limit and linearity are found to be than 4% of reproducibility is observed for the analysis of Sm and Nd. The analytical result with NIST SRM 1633B is also found to be 20.3 ng/ml, which agrees well with tile certified value. 9 References
Metals, rare earth Samarium Neodymium Spectrophotometry Reference material Resin Optimization Column Preconcentration

"Simultaneous Determination Of Hydride And Non-hydride Forming Elements By Inductively Coupled Plasma Atomic-emission Spectrometry"
Anal. Proc. 1992 Volume 29, Issue 10 Pages 438-439
Zhang Li, Susan McIntosh and Walter Slavin

Abstract: Arsenic, Se, Sb, Bi, Cd, Cr, Cu, Fe, Mn, Ni and Pb were determined in the NIST environmental standard reference materials steel, coal fly ash, urban particulated and 1643b water by ICP-AES. A Perkin-Elmer FIAS-2000 flow injection system was used for hydride generation (experimental conditions tabulated). The sample solution was split into two streams, one being pumped directly to the nebulizer, the other mixed with HCl and NaBH4 solution in the mixing tubes of the chemifold. After separation, the hydride was swept into the spray chamber through a slightly modified cross-flow nebulizer cap. The hydride was then carried into the plasma together with sample aerosol. Recoveries of 20 µg L-1 of As, Sb and Se and 50 µg L-1 of non-hydride forming elements in river- and seawater standards were >80%.
Arsenic Selenium Antimony Bismuth Cadmium Chromium Copper Iron Manganese Nickel Lead Spectrophotometry Spectrophotometry Reference material FIAS-200 Nebulizer Volatile generation Volatile generation

"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

"Flow Injection Analysis Of MWC Fly Ash Leaching Characteristics"
J. Air Waste Manage. Assoc. 1995 Volume 45, Issue 11 Pages 871-876
Willemin, J.A.;Nesbitt, C.C.;Dewey, G.R.

Abstract: A completely mixed batch reactor leaching method utilizing flow injection analysis (the CMBR-FIA method) was developed to study the lead leaching characteristics of municipal waste combustor fly ash. Flow injection analysis coupled with atomic absorption spectrophotometry enabled the determination of lead concentrations at one minute intervals. The pH and oxidation-reduction potential of the solution were continuously monitored to characterize the leaching conditions. Automatic titration was used to alter the solution pH to defined endpoints. The CMBR-FIA method offers the ability to immediately observe alterations to the leaching solution, and grants the freedom to study a number of parameters concurrently. The CMBR-FIA method is a rapid and reliable means to investigate leaching characteristics. This paper describes the method and demonstrates its use to monitor the leaching of lead from municipal solid waste combustor fly ash as a function of pH. Soluble lead concentrations are shown to increase quickly with decreasing pH. A maximum of 50% of the total lead concentration was available in solution at pH 2. This value gradually decreased with time to over 35% of the total. (16 references)
Lead Spectrophotometry Reactor pH Process monitoring

"Development Of Flow Injection And Continuous-flow System Using 1,10-phenanthroline Chemiluminescent Detection For Determination Of Small Amounts Of Rare-earth Metal Ions"
Nippon Kagaku Kaishi 1992 Volume 1992, Issue 11 Pages 1332-1338
Ishii, M.;Anazawa, Y.;Akai, T.

Abstract: The cited system consists of three flow lines (flow rate 2.5 mL min-1 each), viz, the NaOH solution line, the surfactant and dye-sensitizer solution line, and the H2O2 and/or sample solution line. Samples are mixed with 1,10-phenanthroline (I) and EDTA and are analyzed by the flow injection or continuous-flow method. The chemiluminescence is produced by reaction of I with reactive O. For Eu, detection limits were 20 nM in 20 µL injection volume and 10 nM in 2.5 mL min-1 continuous sample flows. The upper detection limits were 0.33 to 10 µM by the flow injection method and 10 nM to 0.1 mM by the continuous-flow method. For a 30 µM Eu, the coefficient of variation (n = 5) were 2.2 and 1.7% for the flow injection and continuous-flow methods, respectively. Copper did not interfere. Other rare-earth metals behaved similarly to Eu. Coal fly ash was analyzed using this system. In order to determine small amounts of rare earth metal ions, a new flow injection and continuous-flow system using 1,10-phenanthroline (1,10-Phen) chemiluminescent (CL) detection was developed. The proposed system is comprised of three flow lines at flow rate of 2.5 mL/min each; the sodium hydroxide solution line, the surfactant and dye-sensitizer solution line and the hydrogen peroxide and/or sample solution line. Rare earth metal ion samples containing the mixed reagents of 1,10-Phen and EDTA (H4edta) are analyzed by the flow injection method or by the continuous-flow method. The 1,10-Phen CL for the determination of rare earth metal ions is produced by a reaction of 1,10-Phen and reactive oxygen species produced by a reaction of rare earth metal-edta complex and hydrogen peroxide in the alkaline solution, and enhanced by surfactant and dye-sensitizer. Typical europium(III) anal. characteristics for the proposed system are as follows. The lower detection limits are 2.0 x 10^-8 M (1 M = 1 mol L-1) in 20 µL injection volumes and 1.0 x 10^-8 M in 2.5 mL/min continuous sample flows. The magnitudes for the determination are 3.3 x 10^-7 - 1.0 x 101-5 M by the flow injection method and 1.0 x 10^-8 - 1.0 x 10^-4 M by the continuous sample flow method. Analysis time required is ~12 s by the 20 µL injection method. Relative standard deviations are 2.2% by the flow injection method and 1.7% by the continuous-flow method in 5 repeated runs of the 3 x 10^-5 M europium solutions Copper(II), the substance which may cause the largest interference to the europium CL intensity, did not interfere with the intensity even by the 3 x 10^-7 M coexistence in the 3 x 10^-5 M europium solutions The analytical properties for other rare earth metal ions such as samarium(III) showed the same tendency to those for europium. Coal fly ash was analyzed with the present system.
Metals, rare earth Europium(3+) Chemiluminescence Indirect Interferences