Document Detail

Frequency-domain fluorescence lifetime measurements via frequency segmentation and recombination as applied to pyrene with dissolved humic materials.
MedLine Citation:
PMID:  18546063     Owner:  NLM     Status:  MEDLINE    
In this study, the association behavior of pyrene with different dissolved humic materials (DHM) was investigated utilizing the recently developed segmented frequency-domain fluorescence lifetime method. The humic materials involved in this study consisted of three commercially available International Humic Substances Society standards (Suwannee River fulvic acid reference, SRFAR, Leonardite humic acid standard, LHAS, and Florida peat humic acid standard, FPHAS), the peat derived Amherst humic acid (AHA), and a chemically bleached Amherst humic acid (BAHA). It was found that the three commercial humic materials displayed three lifetime components, while both Amherst samples displayed only two lifetime components. In addition, it was found that the chemical bleaching procedure preferentially removed red wavelength emitting fluorophores from AHA. In regards to pyrene association with the DHM, different behavior was found for all commercially available humics, while AHA and BAHA, which displayed strikingly similar behavior in terms of fluorescence lifetimes. It was also found that there was an enhancement of pyrene's measured lifetime (combined with a decrease in pyrene emission) in the presence of FPHAS. The implications of this long lifetime are discussed in terms of (1) quenching mechanism and (2) use of the fluorescence quenching method used to determine the binding of compounds to DHM.
Hadi M Marwani; Mark Lowry; Baoshan Xing; Isiah M Warner; Robert L Cook
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2008-06-11
Journal Detail:
Title:  Journal of fluorescence     Volume:  19     ISSN:  1053-0509     ISO Abbreviation:  J Fluoresc     Publication Date:  2009 Jan 
Date Detail:
Created Date:  2009-02-05     Completed Date:  2009-05-11     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9201341     Medline TA:  J Fluoresc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  41-51     Citation Subset:  IM    
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
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MeSH Terms
Fluorescent Dyes / chemistry*,  standards
Humic Substances*
Luminescent Measurements / methods*
Oxygen / chemistry
Pyrenes / chemistry*,  standards
Surface Properties
Time Factors
Reg. No./Substance:
0/Fluorescent Dyes; 0/Humic Substances; 0/Pyrenes; 129-00-0/pyrene; 7782-44-7/Oxygen

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