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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Keiji Gamoh

Abbrev:
Gamoh, K.
Other Names:
Address:
Faculty of Education, Kochi University, Akebono-cho, Kochi 780 Japan
Phone:
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Citations 4

"Enzyatmic Activities Of Glucose Oxidase Immobilized Under High-pressure Conditions"
Seibutsu Kogaku Kaishi 1998 Volume 76, Issue 10 Pages 413-418
Keiji Gamoh

Abstract: A method of immobilizing glucose oxidase(GOD)on inorganic supports under high-pressure conditions was developed. The effect of pressure on the amount of GOD adsorbed and on its activity was examined. Using aminopropylsilica gel as a support, the amount of GOD adsorbed increased with increases in the pressure employed. Although the GOD activity generally increased in accord with the amount of adsorbed GOD, the maximum amount of GOD (obtained under a pressure of 800 MPa) did not correspond to the maximum GOD activity. The fact that the GOD activity was not always proportional to the amount of GOD adsorbed indicated that the pressure used had an important bearing on the retention of GOD activity. GOD immobilized at 600 MPa was the most effective in terms of GOD activity. When four kinds of inorganic supports were as to their effectiveness in GOD immobilization, the highest GOD activity was observed when aminopropylsilica gel was used. Gel with immobilized GOD was packed in a column for D-glucose quantitation; good linearity was observed using the flow injection-chemiluminescence method. The enzymatic stability of the GOD column was maintained after the continuous elution of acidic (pH 2.2) and basic (pH 10.2) phosphate buffer solutions. It was thus shown that high pressure can be a parameter for the immobilization of GOD on inorganic supports, which means that a durable column of immobilized GOD can be conveniently produced.
Glutamic acid Chemiluminescence Immobilized enzyme

"Desorption Studies At A Hanging Mercury Drop Electrode By A Flow Injection Method"
J. Electroanal. Chem. 1990 Volume 283, Issue 1-2 Pages 421-424
Hiromiti Sawamoto and Keiji Gamoh

Abstract: A block diagram for the flow injection method is shown. The supporting electrolyte solution (usually 0.1 M KCl), from which O is removed, is placed in the reservoir. An active charcoal column is placed between the peristaltic pump and the injection valve to remove traces of surfactants dissolved in the supporting electrolyte solution. The most important part of the app. is the voltammetric cell, which is made from a Teflon cylinder in which a hanging Hg drop electrode, a calomel electrode, and a Pt electrode are placed. Surfactants are introduced via the injection valve and differential-capacitance-time (C vs. t) curves are measured in the voltammetric cell. The decrease in differential capacitance shows the adsorption of the surfactant. The C vs. t curves for Hg at -0.6 V in 0.1 M KCl with and without additions of saturated n-octyl alcohol and vitamin B12 are shown. The adsorption of the n-octyl alcohol is reversible while that of vitamin B12 is not.
1-Octanol Vitamin B12 Electrode Column Activated carbon

"Effective Separation Of C-24 Epimeric Brassinosteroids By Liquid Chromatography"
Anal. Chim. Acta 1992 Volume 256, Issue 2 Pages 319-322
Keiji Gamoh*, Suguru Takatsuto, Nobuo Ikekawa

Abstract: Brassinolide and castasterone (themselves well separated) were resolved from their 24R-epimers by conversion into 2α,3α;22,23-bis-(3-aminophenylboronate) esters before HPLC on Shim-pack RPC-ODS (5 µm). A solution of the four compounds in acetonitrile was heated at 70°C for 10 min with an equal volume of 0.1% 3-aminophenylboronic acid in acetonitrile - pyridine (99:1), and the resulting mixture was analyzed on a column (25 cm x 4.6 mm) at 45°C with 20 mM 18-crown-6 in acetonitrile - aqueous 1% acetic acid (3:1) as mobile phase (1 mL min-1) and fluorimetric detection at 400 nm (excitation at 330 nm) after post-column derivatization with phthalaldehyde - KCN. For each compound, the calibration graph of peak areas was rectilinear up to 2.4 ng injected, and the detection limit was 40 pg.
Brassinolide Castasterone HPLC Fluorescence Post-column derivatization

"Post-column Liquid Chromatographic Method For The Determination Of Cyanide With Fluorimetric Detection"
Anal. Chim. Acta 1991 Volume 251, Issue 1-2 Pages 255-259
Keiji Gamoh*, Senya Imamichi

Abstract: Cyanide ions were separated from other ions by ion-exclusion HPLC on a Shim-pack SCR-102H column operated at 40°C with 10 mM HClO4 as mobile phase (1 mL min-1). Column eluate was mixed at 40°C with 2 mM phthalaldehyde (OPA) or naphthalenedicarboxaldehyde (NDA) and 20% ethanolic 0.5 mM Na4 EDTA in carbonate - borate buffer solution and then with 2 mM amino acid and 0.5 mM Na4 EDTA in carbonate-borate buffer. Fluorimetric detection was at 400 nm (excitation at 330 nm) for CN- - OPA derivatives or at 490 nm (excitation at 420 nm) for CN- - NDA derivatives. Use of NDA gave the best sensitivity. The calibration graph was rectilinear from 0.5 µg L-1 to 2 mg L-1 of CN-. The detection limit was ~0.1 µg l-1. The coefficient of variation (n = 10) were 1.4% at 10 µg L-1 and 3.1% at 0.5 µg l-1.
Cyanide HPLC Fluorescence Buffer Column Heated reaction Post-column derivatization