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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Journal of Fluorescence

  • Publisher: Springer
  • FAD Code: JFLU
  • CODEN: JOFLEN
  • ISSN: 1053-0509
  • Abbreviation: J. Fluor.
  • DOI Prefix: 10.1007/s10895
  • Language: English

Citations 4

"Photo-induced Fluorescence Of Fluometuron In A Continuous-flow Multicommutation Assembly"
J. Fluor. 2007 Volume 17, Issue 1 Pages 29-36
I. Cydzik, J. R. Albert-García and J. Martínez Calatayud

Abstract: This paper deals with the photo-induced fluorimetric determination of the herbicide Fluometuron with the aid of a continuous-flow assembly of the emergent and new methodology known as Multicommutation which was provided with an on-line photoreactor. Maximum fluorescence intensity was observed at basic pH solutions, 1 x 10^-4 mol L-1 NaOH, after 1.4 min of irradiation and being the maximum at ?exc 247.0 nm and ?em 325.0 nm. The influence of different experimental parameters either chemical (pH, surfactants presence, solvent polarity and temperature) or hydrodynamic (time of photo-degradation, size and number of different segments and flow-rate) was tested. The linear dynamic range was from 0.01 to 4.0 mg L-1 of Fluometuron; the inter-day reproducibility (as RSD) of the slope was 0.001% and 1.7% from the peaks intra-day reproducibility. A large series of potential interferents was studied and finally the method was applied to human urine, soil, formulation and water samples. © Springer Science+Business Media, LLC 2007.

"Chemiluminescence Determination Of Sodium New Houttuyfonate In Pharmaceutical Preparations Based On Tween 80-rhodamine B System"
J. Fluor. 2007 Volume 17, Issue 1 Pages 15-21
Xiao-Feng Yang, Hanchun Yao, Ji-Bao Zhai and Hua Li

Abstract: Strong chemiluminescence (CL) emission was observed when sodium new houttuyfonate (SNH) was mixed with Tween 80 in sulfuric acid medium in the presence of rhodamine B. Base on this phenomenon, a sensitive flow injection-CL method for the determination of SNH was developed. Under the optimum conditions, the CL emission is linearly with SNH concentration in the range 8.0-4000 ng mL-1, with a detection limit of 2.7 ng mL-1 (3?). As a preliminary application, the proposed method was successfully applied to the determination of SNH in pharmaceutical preparations. The possible CL mechanism was also discussed in this paper. © Springer Science+Business Media, LLC 2007.

"FIA-fluorimetric Determination Of The Pesticide 3-indolyl Acetic Acid"
J. Fluor. 2006 Volume 16, Issue 1 Pages 61-67
J. Martínez Calatayud, J. Gonçalves de Ascenção and J. R. Albert-García

Abstract: The paper presents the determination of the pesticide 3-indolyl acetic acid based on its native fluorescence; the method has been optimized either in a flow injection analysis (FIA) assembly or in batch. Maximum fluorescence intensity was observed at basic pH solutions at ?exc = 280 nm and ?em = 364 nm. The influence of different empirical parameters as pH, surfactants presence, solvent polarity, solved oxygen amount, and temperature was studied; highest outputs only required the pH in aqueous solutions to be adjusted over the range 9.5-10.5. Different calibration ranges were obtained by working with three different sensitivity scales of the fluorimeter either in flow injection analysis or batch. With the high sensitivity scale and FIA, the linear dynamic range was from 0.005 to 0.6 mg L-1 3-indolyl acetic acid; with an relative standard deviation (RSD) of 4.9% inter-day reproducibility. A large series of potential interferents was studied and finally, the method was applied to several water samples. © 2006 Springer Science+Business Media, Inc.

"Determination Of Catechin In Aqueous Solution By Chemiluminescence Method"
J. Fluor. 2005 Volume 15, Issue 5 Pages 735-739
Jung Min Lee, Mohammad Mainul Karim and Sang Hak Lee

Abstract: A method to determine catechin in aqueous solution by measuring chemiluminescence intensities using a stopped flow system has been studied. The lucigenin-hydrogen peroxide chemiluminescence reaction was chosen for the determination of catechin. Fe(II) ion was added to the chemiluminescence system to increase the sensitivity. The chemiluminescence intensity from the lucigenin system was increased by the addition of catechin. Effects of flow rates of reagent and sample and concentrations of lucigenin, hydrogen peroxide, Fe(II) ion and KOH were investigated. The calibration curve for catechin was linear over the range from 1.0-10^-6 to 1.0-10^-3 M and the detection limit was 3.0-10^-7 M under the optimal experimental conditions.