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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Ildiko Ipolyi

Abbrev:
Ipolyi, I.
Other Names:
Address:
Department of Applied Chemistry, Szent Istvan University, Budapest Hungary
Phone:
+36-1-372-6253
Fax:
+36-1-466-4272

Citations 3

"Development Of A Method For The Determination Of Selenoamino Acids And Se(IV) By Direct Hydride Generation"
Magy. Kem. Foly. 2001 Volume 107, Issue 1 Pages 31-35
I. Ipolyi, Zs. Stefánka and P. Fodor

Abstract: The speciation of selenocystine (SeCys), selenomethionine (SeMet), selenoethionine (SeEt) and Se(IV) was performed by on-line coupling of high performance liquid chromatography (HPLC) and atomic fluorescence spectrometry (AFS) with hydride generation (HG) as high efficiency sample introduction system. Reversed-phase liquid chromatography was applied to separate the selenium species with 10 mM ammonium-acetate buffer eluent adjusted to pH 4. The operating conditions for chromatographic separation (gradient elution, run time) and hydride generation (concentration of HCl and NaBH4 solution, argon and hydrogen flow rates) were carefully optimized. The efficiency of hydride generation for all of the four species vas determined. Detection limits (DLs) obtained for SeCys, SeMet, SeEt and Se(IV) are 18, 70, 96, and 16 µg L-1 respectively. The analytical performance of the method was controlled by measuring the selenium content of spiked selenium food supplements. The recoveries were in the range 90-110%.
Speciation

"Speciation Of Inorganic Selenium And Selenoamino Acids By An HPLC-UV-HG-AFS System"
J. Autom. Methods Manag. Chem. 2001 Volume 23, Issue 6 Pages 167-172
I. Ipolyi, W. Corns, P. Stockwell, P. Fodor

Abstract: For the on-line speciation of selenocystine (SeCys), selenomethionine (SeMet), selenoethionine (SeEt), selenite (Se(IV)) and selenate (Se(VI)), a high-performance liquid chromatography-UV irradiation-hydride generation-atomic fluorescence spectrometric method is described. Separation was carried out on a conventional reversed-phase C18 column modified with didodecyl-dimethylammonium bromide with gradient elation applying two concentrations of amonium acetate as the mobile phase. UV irradiation and hydride generation parameters were optimized, The obtained detection limits for SeCys, SeMet. SeEt, Se(IV) and Se(VI) were 0.31. 0.43, 0.7, 0.44 and 0.32 ng mL-1, respectively using a 100 µL loop. The method was tested with spiked mineral water and two volunteers urine samples.

"Speciation Of Se(IV) And The Selenoamino Acids By High-performance Liquid Chromatography-direct Hydride Generation-atomic Fluorescence Spectrometry"
Anal. Chim. Acta 2001 Volume 435, Issue 2 Pages 367-375
I. Ipolyi, Zs. Stefánka and P. Fodor

Abstract: The speciation of selenocystine (SeCys), selenomethionine (SeMet), selenoethionine (SeEt) and Se(IV) was performed by on-line coupling of high-performance liquid chromatography (HPLC) and atomic fluorescence spectrometry (AFS) with hydride generation (HG) as high efficiency sample introduction system. Reversed-phase liquid chromatography was applied to separate the selenium species with 0.01 M ammonium acetate buffer (pH = 4) eluent containing 0.5% (v/v) methanol and 0.1 mol L-1 of DDAB. The operating conditions for chromatographic separation (gradient elution, run time) and hydride generation (concentration of HCl and NaBH4 solution, argon and hydrogen flow rates) were carefully optimized. The efficiency of hydride generation for all of the four species was measured. Detection limits (DLs) obtained for SeCys, SeMet, SeEt and Se(IV) are 18, 70, 96, and 16 µg L-1, respectively. The analytical performance of the method was controlled by measuring the selenium content of spiked selenium food supplements. The range of obtained recoveries is 90-110%.
Speciation