Singlet Oxygen Phosphorescence as a Probe for Triplet-State Dissolved Organic Matter Reactivity

Erickson, Paul R.; Moor, Kyle J.; Werner, Jeffrey J.; Latch, Douglas E.; Arnold, William A.; McNeill, Kristopher

doi:10.1021/acs.est.8b02379

Cited by 90 publications

(112 citation statements)

References 49 publications

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“…Finally, the higher photochemical reactivity of PLFA might be related to its molecular composition, which is dominated by bacterial-and algal-derived organic matter. 20 This difference in source material compared to terrestrially-derived DOM might result in a different distribution of S oxidation states, an increased photochemical reactivity (already documented for triplet DOM-related processes) 25 , or a combination of these two factors.…”

mentioning

confidence: 99%

Photochemical Production of Sulfate and Methanesulfonic Acid from Dissolved Organic Sulfur

Ossola

Tolu

Clerc

et al. 2019

Environ. Sci. Technol.

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Photodegradation processes play an important role in releasing elements tied up in biologically refractory forms in the environment, and are increasingly recognized as important contributors to biogeochemical cycles. While complete photooxidation of dissolved organic carbon (to CO 2), and dissolved organic phosphorous (to PO 4 3-) has been documented, the analogous photoproduction of sulfate from dissolved organic sulfur (DOS) has not yet been reported. Recent high-resolution mass spectrometry studies showed a selective loss of organic sulfur during photodegradation of dissolved organic matter, which was hypothesized to result in the production of sulfate. Here, we provide evidence of ubiquitous production of sulfate, methanesulfonic acid (MSA) and methanesulfinic acid (MSIA) during photodegradation of

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mentioning

confidence: 99%

Photochemical Production of Sulfate and Methanesulfonic Acid from Dissolved Organic Sulfur

Ossola

Tolu

Clerc

et al. 2019

Environ. Sci. Technol.

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“…However, these processes do not necessarily modify the compounds themselves. The quenching rate constant describes the sum of physical quenching and actual reactions, and it can be determined by laser flash photolysis using either proxy molecules (the triplet states of which simulate the behavior of 3 CDOM*) or, more recently, actual CDOM [56,57]. Unfortunately, the quenching rate constants are only upper limits for the reaction rate constants that are involved in the actual transformation of the substrates.…”

Section: Reaction With 3 Cdom*mentioning

confidence: 99%

A Critical View of the Application of the APEX Software (Aqueous Photochemistry of Environmentally-Occurring Xenobiotics) to Predict Photoreaction Kinetics in Surface Freshwaters

Vione

2019

Molecules

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The APEX (aqueous photochemistry of environmentally occurring xenobiotics) software computes the phototransformation kinetics of compounds that occur in sunlit surface waters. It is free software based on Octave, and was originally released in 2014. Since then, APEX has proven to be a remarkably flexible platform, allowing for the addressing of several environmental problems. However, considering APEX as a stand-alone software is not conducive to exploiting its full potentialities. Rather, it is part of a whole ecosystem that encompasses both the software and the laboratory protocols that allow for the measurement of substrate photoreactivity parameters. Coherently with this viewpoint, the present paper shows both how to use APEX, and how to experimentally derive or approximately assess the needed input data. Attention is also given to some issues that might provide obstacles to users, including the extension of APEX beyond the simple systems for which it was initially conceived. In particular, we show how to use APEX to deal with compounds that undergo acid-base equilibria, and with the photochemistry of systems such as stratified lakes, lakes undergoing evaporation, and rivers. Hopefully, this work will provide a reference for the smooth use of one of the most powerful instruments for the modeling of photochemical processes in freshwater environments. All authors have read and agreed to the published version of the manuscript. Molecules 2020, 25, 9 2 of 34 the main ones in surface waters being chromophoric dissolved organic matter (CDOM), nitrate, and nitrite [3,4]. The irradiation of all the mentioned photosensitizers yields the photoreactive transient • OH (hydroxyl radical), which can produce another transient (CO 3 •− , the carbonate radical) upon reaction with inorganic carbon species (HCO 3 − and CO 3 2− ) [5]. Irradiated CDOM can also produce reactive triplet states ( 3 CDOM*), and the latter yield singlet oxygen ( 1 O 2 ) upon reaction with dissolved O 2 [3,6]. All the mentioned transient species ( • OH, CO 3 •− , 3 CDOM*, and 1 O 2 ) are involved to some extent in indirect pollutant phototransformation, depending on the reactivity of the given pollutant towards each transient [7,8]. Although they play a key role in indirect phototransformation of pollutants, the transients are mostly scavenged/quenched by natural water components. The latter include: (i) dissolved organic matter (DOM, either chromophoric or not), HCO 3 − and CO 3 2− in the case of • OH (plus Br − , which plays the main role in some saltwaters and in seawater); (ii) DOM again in the case of CO 3 •− ; (iii) dissolved O 2 for 3 CDOM*; and (iv) the water solvent for 1 O 2 [7]. The main mentioned formation and scavenging processes are summarized by the reactions below [3-7]: Molecules 2020, 25, 9 3 of 34 to validate this approach by comparing the predicted kinetics with known field data of pollutant phototransformation. Validation has been obtained in the cases of carbamazepine [18], ibuprofen [19], diclofenac and naproxen [20], atrazine [2...

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“…Finally, the higher photochemical reactivity of PLFA might be related to its molecular composition, which is dominated by bacterialand algal-derived organic matter. 10 This difference in source material compared to terrestrially derived DOM might result in a different distribution of S oxidation states, an increased photochemical reactivity (already documented for triplet DOM-related processes) 15 , or a combination of these two factors.…”

Section: Photochemical Production Of Sulfate From Dosmentioning

confidence: 99%

Photochemical Production of Sulfate and Methanesulfonic Acid from Dissolved Organic Sulfur in Natural Waters

Ossola

Tolu²,

Clerc³

et al. 2019

Preprint

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Despite its importance in biological processes and its influence on metal bioavailability, the biogeochemical cycle of dissolved organic sulfur (DOS) in aquatic systems is still poorly understood. Recent high-resolution mass spectrometry (HRMS) studies showed a selective loss of organic sulfur during photodegradation of dissolved organic matter (DOM), which was hypothesized to result in the production of sulfate. Here, we provide evidence of ubiquitous production of sulfate, methanesulfonic acid (MSA) and methanesulfinic acid (MSIA) during photodegradation of DOM samples from a wide range of natural terrestrial environments. We show that photochemical production of sulfate is generally at least one order of magnitude more efficient than the production of MSA and MSIA, as well as volatile S-containing compounds (i.e., CS2and COS). We also identify possible molecular precursors for sulfate and MSA, and we demonstrate that a wide range of relevant classes of DOS compounds (in terms of S oxidation state and molecular structure) can liberate sulfate upon photosensitized degradation. This work indicates that photochemistry plays a more significant role in the aquatic and atmospheric cycle of DOS than currently believed.

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Singlet Oxygen Phosphorescence as a Probe for Triplet-State Dissolved Organic Matter Reactivity

Cited by 90 publications

References 49 publications

Photochemical Production of Sulfate and Methanesulfonic Acid from Dissolved Organic Sulfur

Photochemical Production of Sulfate and Methanesulfonic Acid from Dissolved Organic Sulfur

A Critical View of the Application of the APEX Software (Aqueous Photochemistry of Environmentally-Occurring Xenobiotics) to Predict Photoreaction Kinetics in Surface Freshwaters

Photochemical Production of Sulfate and Methanesulfonic Acid from Dissolved Organic Sulfur in Natural Waters

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