Factors influencing fluorescence spectra of free porphyrins
We recorded fluorescence excitation and emission spectra of uro- and coproporphyrin under different experimental conditions, to see how these conditions influence quantification based on measurement of fluorescence intensity. We found that, for bands α and β of the emission spectra and the main peak...
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todo:paper_00099147_v34_n4_p757_Polo2023-10-03T14:08:52Z Factors influencing fluorescence spectra of free porphyrins Polo, C.F. Frisardi, A.L. Resnik, E.R. Schoua, A.E.M. Del Batlle, C.A.M. porphyrin fluorescence nonhuman Coproporphyrins Hydrogen-Ion Concentration Osmolar Concentration Porphyrins Solvents Spectrometry, Fluorescence Support, Non-U.S. Gov't Uroporphyrins We recorded fluorescence excitation and emission spectra of uro- and coproporphyrin under different experimental conditions, to see how these conditions influence quantification based on measurement of fluorescence intensity. We found that, for bands α and β of the emission spectra and the main peak of the excitation spectra, fluorescence depends on pH and is minimal near pH 5 and near pH 7-7.5 for copro- and uroporphyrin, respectively. For band γ of the emission spectra there was a constant decrease of fluorescence with increasing alkalinity of the solution. The intensity of porphyrin fluorescence also depends on ionic strength, reaching sharp maxima at 0.1 mol/L (for uroporphyrin) and 1 mol/L (for coproporphyrin). The organic mixture ethyl acetate:acetic acid (4:1 by vol), commonly used to extract porphyrins from biological samples, markedly diminishes the fluorescence of both porphyrins as compared with the same concentration of each porphyrin in aqueous acidic solvent. Furthermore, when we measured different ratios of uro:copro mixture at three distinct pHs and buffers, we found that at pH 10.5 (in carbonate buffer) the measured units of fluorescence depend only on total porphyrin concentration and not on the composition of the mixture. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00099147_v34_n4_p757_Polo |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
porphyrin fluorescence nonhuman Coproporphyrins Hydrogen-Ion Concentration Osmolar Concentration Porphyrins Solvents Spectrometry, Fluorescence Support, Non-U.S. Gov't Uroporphyrins |
| spellingShingle |
porphyrin fluorescence nonhuman Coproporphyrins Hydrogen-Ion Concentration Osmolar Concentration Porphyrins Solvents Spectrometry, Fluorescence Support, Non-U.S. Gov't Uroporphyrins Polo, C.F. Frisardi, A.L. Resnik, E.R. Schoua, A.E.M. Del Batlle, C.A.M. Factors influencing fluorescence spectra of free porphyrins |
| topic_facet |
porphyrin fluorescence nonhuman Coproporphyrins Hydrogen-Ion Concentration Osmolar Concentration Porphyrins Solvents Spectrometry, Fluorescence Support, Non-U.S. Gov't Uroporphyrins |
| description |
We recorded fluorescence excitation and emission spectra of uro- and coproporphyrin under different experimental conditions, to see how these conditions influence quantification based on measurement of fluorescence intensity. We found that, for bands α and β of the emission spectra and the main peak of the excitation spectra, fluorescence depends on pH and is minimal near pH 5 and near pH 7-7.5 for copro- and uroporphyrin, respectively. For band γ of the emission spectra there was a constant decrease of fluorescence with increasing alkalinity of the solution. The intensity of porphyrin fluorescence also depends on ionic strength, reaching sharp maxima at 0.1 mol/L (for uroporphyrin) and 1 mol/L (for coproporphyrin). The organic mixture ethyl acetate:acetic acid (4:1 by vol), commonly used to extract porphyrins from biological samples, markedly diminishes the fluorescence of both porphyrins as compared with the same concentration of each porphyrin in aqueous acidic solvent. Furthermore, when we measured different ratios of uro:copro mixture at three distinct pHs and buffers, we found that at pH 10.5 (in carbonate buffer) the measured units of fluorescence depend only on total porphyrin concentration and not on the composition of the mixture. |
| format |
JOUR |
| author |
Polo, C.F. Frisardi, A.L. Resnik, E.R. Schoua, A.E.M. Del Batlle, C.A.M. |
| author_facet |
Polo, C.F. Frisardi, A.L. Resnik, E.R. Schoua, A.E.M. Del Batlle, C.A.M. |
| author_sort |
Polo, C.F. |
| title |
Factors influencing fluorescence spectra of free porphyrins |
| title_short |
Factors influencing fluorescence spectra of free porphyrins |
| title_full |
Factors influencing fluorescence spectra of free porphyrins |
| title_fullStr |
Factors influencing fluorescence spectra of free porphyrins |
| title_full_unstemmed |
Factors influencing fluorescence spectra of free porphyrins |
| title_sort |
factors influencing fluorescence spectra of free porphyrins |
| url |
http://hdl.handle.net/20.500.12110/paper_00099147_v34_n4_p757_Polo |
| work_keys_str_mv |
AT polocf factorsinfluencingfluorescencespectraoffreeporphyrins AT frisardial factorsinfluencingfluorescencespectraoffreeporphyrins AT resniker factorsinfluencingfluorescencespectraoffreeporphyrins AT schouaaem factorsinfluencingfluorescencespectraoffreeporphyrins AT delbatllecam factorsinfluencingfluorescencespectraoffreeporphyrins |
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1807322685871489024 |