Time-Resolved Fluorescence Spectra of Untreated and Sodium Borohydride-Reduced Chromophoric Dissolved Organic Matter

2020 ◽  
Vol 54 (19) ◽  
pp. 12109-12118
Author(s):  
Yuan Chen ◽  
Juan Liu ◽  
Xu Zhang ◽  
Neil V. Blough
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Sodium Borohydride ◽  
Fluorescence Spectra ◽  
Chromophoric Dissolved Organic Matter ◽  
Time Resolved Fluorescence ◽  
Time Resolved

scholarly journals Binding of Calcium and Magnesium Ions to Terrestrial Chromophoric Dissolved Organic Matter (CDOM): A Combination of Steady-State and Time-Resolved Fluorescence Study

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2182
Author(s):  
Juan Liu ◽  
Ruiya Zhou ◽  
Xu Zhang
Keyword(s):  
Organic Matter ◽  
Steady State ◽  
Fluorescence Quenching ◽  
Dissolved Organic Matter ◽  
Fluorescence Decay ◽  
Chromophoric Dissolved Organic Matter ◽  
Time Resolved Fluorescence ◽  
High Concentration ◽  
Time Resolved ◽  
Order Of Magnitude

Revealing the binding properties of calcium ion (Ca2+) and magnesium ion (Mg2+) to terrestrial chromophoric dissolved organic matter (CDOM) facilities understanding the effect of natural water components on the photophysics of dissolved organic matter. Steady-state and time-resolved fluorescence spectrometry, and dynamic light scattering were applied to investigate the fluorescence quenching process of CDOM by Ca2+ and Mg2+. Due to a remarkable decrease of the steady-state fluorescence intensity and a slight decrease of fluorescence lifetime, the fluorescence quenching of CDOM by cations mainly occurred through a static process. The fluorescence quenching was profound under longer excitation and emission wavelengths. The binding constant (K, L/mol) for Ca2+ to CDOM ranged from 4.29 to 5.09 (lgK), which was approximately one order of magnitude higher than that of Mg2+ to CDOM (3.86 to 4.56). Nevertheless, the efficiency of CDOM fluorescence quenching by Ca2+, Mg2+ was much lower than that by Cu2+. Fluorescence decay became faster in the presence of a high concentration of Ca2+ (>20 mg/L) and Mg2+ (>50 mg/L). In the presence of these two metal ions, particularly for Ca2+, the lifetime of CDOM excited states shifted to the relatively small value side, indicating fluorescence quenching of CDOM mainly occurred through the interaction of Ca2+/Mg2+ with relatively long-lived fluorophores.

A time-resolved fluorescence study of dissolved organic matter in a riverine to marine transition zone

2002 ◽  
Vol 78 (2-3) ◽  
pp. 121-135 ◽  
Author(s):  
Catherine D. Clark ◽  
Jennifer Jimenez-Morais ◽  
Guilford Jones ◽  
Eliete Zanardi-Lamardo ◽  
Cynthia A. Moore ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Transition Zone ◽  
Time Resolved Fluorescence ◽  
Fluorescence Study ◽  
Time Resolved

scholarly journals Binding of Calcium and Magnesium Ions to Chromophoric Dissolved Organic Matter (CDOM): A Combination of Steady-State and Time-Resolved Fluoresce Study

2021 ◽  
Author(s):  
Xu Zhang ◽  
Juan Liu ◽  
Ruiya Zhou
Keyword(s):  
Organic Matter ◽  
Steady State ◽  
Fluorescence Quenching ◽  
Dissolved Organic Matter ◽  
Fluorescence Decay ◽  
Chromophoric Dissolved Organic Matter ◽  
Time Resolved ◽  
Water Composition ◽  
Terrestrial Source ◽  
Order Of Magnitude

Revealing the binding properties of calcium ion (Ca2+) and magnesium ion (Mg2+) to chromophoric dissolved organic matter (CDOM) facilities understanding the effect of natural water composition on the photophysics of dissolved organic matter. Steady-state and time-resolved fluorescence spectrometry, and dynamic light scattering were applied to investigate the fluorescence quenching process of CODM by Ca2+ and Mg2+. The binding of Ca2+ and Mg2+ preferred terrestrial CDOM to aquatic CDOM. The fluorescence quenching of CDOM by cations mainly occurred in a static process, which was based on the fact that the decrease of steady-state fluorescence intensity was greater than fluorescence lifetime. The fluorescence quenching was profound under longer excitation and emission wavelength. The binding constant (K, L/mol) for Ca2+ to CDOM from terrestrial source ranged from 4.29 to 5.09 (lgK), which was approximately one order of magnitude higher than that of Mg2+ to CDOM (3.86 to 4.56). Fluorescence decay became faster in the presence of Ca2+ and Mg2+. Lifetime distribution of CDOM excited states shifted to small value side in the presence of metal ions, particularly for Ca2+, indicating fluorescence quenching of CDOM mainly through the interaction of Ca2+/Mg2+ with relatively long-lived fluorophores.

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