University of North Florida
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Contact Info

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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Koichi Oguma

Abbrev:
Oguma, K.
Other Names:
Address:
Department of Materials Technology, Faculty of Engineering, Chiba University, Yayoicho, Inage, Chiba 263-8522, Japan
Phone:
+81-43-290-3502
Fax:
+81-43-290-3502

Citations 12

"Flow Injection Simultaneous Determination Of Iron(III) And Copper(II) And Of Iron(III) And Palladium(II) Based On Photochemical Reactions Of Thiocyanato-complexes"
Talanta 2002 Volume 58, Issue 6 Pages 1077-1087
Koichi Oguma and Osamu Yoshioka

Abstract: The flow injection analysis systems have been developed for the simultaneous determination of iron(III) and copper(II) and of iron(III) and palladium(II) based on the photochemical reactions of their thiocyanato-complexes. In the first system, a sample solution was injected in to nitric acid solution and mixed with ammonium thiocyanate solution, followed by spectrophotometric monitoring of the thiocyanato-complexes formed. Another aliquot of the same sample solution was injected and the thiocyanato-complexes formed in the same way were irradiated by UV light before spectrophotometric monitoring. In another system, the absorbance of thiocyanato-complexes formed by each sample injection was monitored with two flow cells aligned with the same optical path before and after UV irradiation. The difference in the extent of photochemical decomposition of the thiocyanato-complexes enabled simultaneous determinations of iron(III) and copper(II) and of iron(III) and palladium(II) at levels of several µg mL-1 to some tens µg mL-1 in their admixtures. Sample throughputs are 40 and 20 h-1 by the former and latter systems, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.

"Microchemical Determination Of Iodate And Iodide In Sea-waters By Flow Injection Analysis"
Microchim. Acta 1993 Volume 110, Issue 1-3 Pages 71-77
Koichi Oguma, Kazuyuki Kitada and Rokuro Kuroda

Abstract: Filtered seawater samples were diluted to a salinity of 1.2%. The total inorganic iodine (i.e. IO3- and I-) was determined by injecting the diluted samples (128 µL) into a carrier stream of aqueous 2% NaCl. The sample stream was merged with a flow of 50 mM ammonium ferric sulfate solution in 4.6 M HNO3. The stream then merged with a stream of 2.4 mM KSCN - 1.5 mM NaNO2 before passing through a reaction column at 50°C. The absorbance of the column effluent was monitored at 460 nm. Determination of IO3- was effected by passing the sample carrier stream through a Bio-Rad AG1-X4 anion-exchange resin column (10 cm x 0.5 mm) to remove I- before repeating the above procedure. Recoveries were >97% and the coefficient of variation was 1.3%. The method was applied to seawater samples with a total iodine content ranging from 0.75 to 150 ng mL-1. Results are presented.
Iodate Iodide Sea Spectrophotometry Resin Biorad

"Determination Of Cobalt In Seawater By Flow Injection Analysis"
J. Flow Injection Anal. 1996 Volume 13, Issue 2 Pages 168-168
Oguma, K.

Abstract: A brief review is presented, which includes techniques especially for in situ flow injection analysis of seawater from various depths from on board the research ship. (5 references).
Cobalt Sea Environmental Remote instrument Review

"Flow Injection Analysis Bibliography (22)"
J. Flow Injection Anal. 1994 Volume 11, Issue 2 Pages 199-217
Oguma, K.

Abstract: A bibliography is presented. All titles are in English. (? references).
Bibliography

"Online Column Separation And Preconcentration In Flow Injection Analysis"
J. Flow Injection Anal. 1993 Volume 10, Issue 2 Pages 173-186
Koichi Oguma

Abstract: A review is presented of the use of online column separation and pre-concentration in FIA. The methods reviewed have greatly improved the sensitivity and selectivity of FIA. (34 references).
Review Preconcentration Selectivity Sensitivity

"Flow Injection Analysis"
Bunseki 1989 Volume 1989, Issue 6 Pages 408-418
Oguma, K.

Abstract: A review with 18 references is given on the working principle, characteristics, and application of flow-injection analysis (FIA), basic and special FIA systems. (SFS)
Review

"Flow Injection Analysis. Its Application To Inorganic Analysis"
Bunseki 1988 Volume 1988, Issue 1 Pages 31-36
Oguma, K.

Abstract: A review with 139 references is given on the theory, application, and detectors in flow-injection analysis and determination of inorganic components by using flow-injection analysis. (SFS)
Review

"Differential Determination Of Traces Of Arsenic (III) And Arsenic (V) In Water By Flow Injection On-line Preconcentration-graphite Furnace AAS"
Bunseki Kagaku 2001 Volume 50, Issue 12 Pages 885-891
Yoshihiro Hirano, Hiroki Sakurai, Akihiro Endo, Koichi Oguma and Yasushi Terui

Abstract: A flow injection (FI) on-line pre-concentration-graphite furnace atomic absorption spectrometric method was developed for the determination of traces of As-III. and As-V in water. For an As-III determination, 2 mL of sample was mixed in a FI system with an ammonium pyrrolidinedithiocarbamate (APDC) solution; an As-III-PDC complex was formed. The complex was adsorbed on a C-18 silica gel microcolumn and then eluted with ethanol. The eluate zone containing the highest analyte concentration was injected into the graphite furnace via an autosampler nozzle. After the injection of a Pd matrix modifier solution, As-III. was atomized. The determination of As-V was performed by the same FI system by replacing the APDC solution and ethanol with a Mo-Malachite Green (MG) solution and dimethylsulfoxide (DMSO), respectively. Four milliliters of the sample were mixed with a Mo-MG solution, and the resulting As-V-Mo-MG aggregate was adsorbed on the microcolumn and then eluted with DMSO. The eluate zone containing the highest analyte concentration was injected into a graphite furnace and atomized in the same nrl as in the As-III determination. The method was successfully applied to the determination of As and As-V in lake water. The sensitivity enhancement was about 20-fold for both 2 mL of an As-III. solution and 4 mL of an As-V solution. The detection limits, based on three-times the standard deviation of six replicate measurements of a blank solution, were 0.042 and 0.017 µg L-1 for As-III. and As-V, respectively. The recoveries were 98±6.(5) and 98±6.(0)%, and the sample throughputs were 15 and 12 samples per hour for As-III and As-V, respectively.
Speciation Extraction

"Preparation Of A Tellurium Ion-selective Membrane Electrode Using An Anion-exchange Resin And Its Application To Chemical Analysis Of Industrial Materials"
Bunseki Kagaku 2000 Volume 49, Issue 10 Pages 791-794
Nobutaka Yoshikuni, Seiichi Nishiumi and Koichi Oguma

Abstract: The preparation and application of a coated-graphite tellurium(IV) ion-selective electrode, based on the TeCl62- form anion-exchange resin fixed in a poly(vinyl chloride) matrix, are described. The effects of the hydrochloric acid concentration and interference ions were investigated. The electrode showed a near-Nernstian slope of 30±2 mV/decade over a tellurium(IV) ion concentration range of 3 x 10^-4 - 10^-2 mol L-1 and a response time of 30 s in 6 mol L-1 hydrochloric acid solution. Na+, K+ and Ca2+. do not interfere, but other ions, such as Bi3+, Cd2+, Fe3+, Ga3+, Sb3+,ClO4-, PO43- and SO42-, cause interference. The electrode has been successfully used to determine tellurium in Bi2Te3 and CdTe after the separation of tellurium from bismuth or cadmium by the hydroxide precipitation method in the presence of EDTA as a masking reagent for bismuth and cadmium.

"Indirect Determination Of Uranium By The On-line Reduction And Fluorimetric Detection Of Cerium(III)"
Anal. Sci. 2005 Volume 21, Issue 2 Pages 155-159
Chatchalida BOONPANAID* and Koichi OGUMA**

Abstract: A novel flow injection method has been developed for the indirect determination of uranium by the on-line reduction and subsequent fluorimetric detection of cerium(III). A sample solution containing uranium(VI), prepared as a sulfuric acid solution, was injected into a sulfuric acid carrier solution and passed through a column packed with metal bismuth to reduce uranium(VI) to uranium(IV). The sample solution was merged with a cerium(IV) solution to oxidize uranium(IV) to uranium(VI) and the cerium(III) generated was then monitored fluorimetricaly. The present method is free from interference from zirconium, lanthanides, and thorium, and has been successfully applied to the determination of uranium in monazite coupled with an anion-exchange separation in a sulfuric acid medium to eliminate iron(III). The sample throughput was 25 per hour and the lowest detectable concentration was 0.0042 mg l-1.

"On-line Preconcentration And Determination Of Traces Of Lead In River-water And Seawater By Flow Injection-flame Atomic Absorption Spectrometry And ICP-mass Spectrometry"
Anal. Sci. 2002 Volume 18, Issue 3 Pages 351-354
Tatsuya SEKI), Yoshihiro HIRANO) and Koichi OGUMA

Abstract: In 1994, a lead-selective chromatographic resin was developed by Horwitz et al. The resin was prepared by impregnating Amberchrom CG-71 md resin (Supelco) with an isodecanol solution of bis-4,4'(5')-[tert-butylcyclohexano]-18-crown-6 and it is now commercially available as Pb-Spec™ (EIChrom Industries, Darien, IL). Pb-Spec™ exhibits high selectivity to lead(II) and shows no affinity for the alkali metal ions and other heavy metal ions, therefore, the resin has been successfully applied by the present authors to pre-concentration of lead in steel by an FI technique. This work was undertaken to extend the excellent utility of Pb-Spec™ to the precise determination of traces of lead in river-water and seawater by FI on-line pre-concentration coupled with flame atomic absorption spectrometry (FAAS) or ICP Mass Spectrometry (ICP-MS).

"On-line Preconcentration And Determination Of Lead In Iron And Steel By Flow Injection-flame Atomic Absorption Spectrometry"
Anal. Sci. 2000 Volume 16, Issue 5 Pages 513-516
Tatsuya SEKI), Hiroyuki TAKIGAW), Yoshihiro HIRANO), Yoichi ISHIBASHI) and Koichi OGUMA

Abstract: A flow injection method has been developed for the determination of lead in steel samples by coupling on-line pre-concentration on a lead selective resin, Pb.SpecTM, with flame atomic absorption spectrometry. The sample prepared as a nitric acid solution is passed through a column packed with Pb.SpecTM. The lead retained on the column is then eluted with ammonium oxalate solution and introduced directly into the nebulizer of a flame atomic absorption spectrophotometer. The proposed method was successfully applied to the determination of lead in pure iron certified reference material [0.19±0.01 ppm (n=6); certified value: 0.2 ppm] and lead-free cutting steel certified reference material [0.0952±0.0008% (n=3); certified value: 0.097%]. The detection limit (3 ) was 0.05 g of lead.