Probe Compounds to Assess the Photochemical Activity of Dissolved Organic Matter

Rosario‐Ortiz, Fernando L.; Canonica, Silvio

doi:10.1021/acs.est.6b02776

Cited by 247 publications

(218 citation statements)

References 175 publications

(502 reference statements)

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“…The polydisperse flow of dry aerosols was used to generate a monodisperse flow with a TSI differential mobility analyser (DMA; TSI model 3082) operating with a sheath-to-sample flow ratio of 10 : 1. The monodispersed dry aerosol flow was subsequently split in two and sampled by a TSI condensation particle counter (CPC-3772) and a Droplet Measurement Technologies cloud condensation nuclei chamber (CCNC-100) (Roberts and Nenes, 2005;Rose et al, 2008). The CCNC operated with a total flow of 0.5 L min −1 , corresponding to a high RH exposure time of approximately 10 s for the aerosols.…”

Section: Cloud Condensation Nuclei Counter Setupmentioning

confidence: 99%

Photomineralization mechanism changes the ability of dissolved organic matter to activate cloud droplets and to nucleate ice crystals

et al. 2019

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Abstract. An organic aerosol particle has a lifetime of approximately 1 week in the atmosphere during which it will be exposed to sunlight. However, the effect of photochemistry on the propensity of organic matter to participate in the initial cloud-forming steps is difficult to predict. In this study, we quantify on a molecular scale the effect of photochemical exposure of naturally occurring dissolved organic matter (DOM) and of a fulvic acid standard on its cloud condensation nuclei (CCN) and ice nucleation (IN) activity. We find that photochemical processing, equivalent to 4.6 d in the atmosphere, of DOM increases its ability to form cloud droplets by up to a factor of 2.5 but decreases its ability to form ice crystals at a loss rate of −0.04 ∘CT50 h−1 of sunlight at ground level. In other words, the ice nucleation activity of photooxidized DOM can require up to 4 ∘C colder temperatures for 50 % of the droplets to activate as ice crystals under immersion freezing conditions. This temperature change could impact the ratio of ice to water droplets within a mixed-phase cloud by delaying the onset of glaciation and by increasing the supercooled liquid fraction of the cloud, thereby modifying the radiative properties and the lifetime of the cloud. Concurrently, a photomineralization mechanism was quantified by monitoring the loss of organic carbon and the simultaneous production of organic acids, such as formic, acetic, oxalic and pyruvic acids, CO and CO2. This mechanism explains and predicts the observed increase in CCN and decrease in IN efficiencies. Indeed, we show that photochemical processing can be a dominant atmospheric ageing process, impacting CCN and IN efficiencies and concentrations. Photomineralization can thus alter the aerosol–cloud radiative effects of organic matter by modifying the supercooled-liquid-water-to-ice-crystal ratio in mixed-phase clouds with implications for cloud lifetime, precipitation patterns and the hydrological cycle.Highlights. During atmospheric transport, dissolved organic matter (DOM) within aqueous aerosols undergoes photochemistry. We find that photochemical processing of DOM increases its ability to form cloud droplets but decreases its ability to form ice crystals over a simulated 4.6 d in the atmosphere. A photomineralization mechanism involving the loss of organic carbon and the production of organic acids, CO and CO2 explains the observed changes and affects the liquid-water-to-ice ratio in clouds.

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Section: Cloud Condensation Nuclei Counter Setupmentioning

confidence: 99%

Photomineralization mechanism changes the ability of dissolved organic matter to activate cloud droplets and to nucleate ice crystals

et al. 2019

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“…Because 1 O 2 is a selective electrophile preferentially reacting with electronrich functional groups like suldes, phenols, alkenes and aromatic compounds, anilines, furans, and other electron-rich heterocycles, 58,65,66 it was hypothesized QACs would have limited interaction with this reactive oxygen species. Moreover, because DOM can be a microheterogeneous environment in which 1 O 2 potentially reaches higher steady-state concentrations 51,67 and QACs will associate with DOM, enhanced reactivity might occur if in fact they do react with 1…”

Section: Assessing Reactivity With Other Pprismentioning

confidence: 99%

Photochemical fate of quaternary ammonium compounds in river water

Hora

Arnold

2020

Environ. Sci.: Processes Impacts

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“…26,27 DOM photochemistry is commonly evaluated with the 3 DOM probes sorbic acid (HDA) and 2,4,6-trimethylphenol (TMP), and the 1 O 2 probe furfuryl alcohol (FFA). 28 While HDA and TMP directly measure 3 DOM and 1 O 2 is formed from the reaction of 3 DOM and O 2 , there is evidence that these probes measure distinct 3 DOM subpopulations. 15,29 Recent reviews have proposed using a combination of multiple probes to better describe 3 DOM photoreactivity.…”

Section: Introductionmentioning

confidence: 99%

“…15,29 Recent reviews have proposed using a combination of multiple probes to better describe 3 DOM photoreactivity. 30,31 …”

Section: Introductionmentioning

confidence: 99%

Relationships Between Dissolved Organic Matter Composition and Photochemistry in Lakes of Diverse Trophic Status

Maizel

Remucal

2017

Environ. Sci. Technol.

138

167

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The North Temperate Lakes Long-Term Ecological Research site includes seven lakes in northern Wisconsin that vary in hydrology, trophic status, and landscape position. We examine the molecular composition of dissolved organic matter (DOM) within these lakes using Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) and quantify DOM photochemical activity using probe compounds. Correlations between the relative intensity of individual molecular formulas and reactive species production demonstrate the influence of DOM composition on photochemistry. For example, highly aromatic, tannin-like formulas correlate positively with triplet formation rates, but negatively with triplet quantum yields, as waters enriched in highly aromatic formulas exhibit much higher rates of light absorption, but only slightly higher rates of triplet production. While commonly utilized optical properties also correlate with DOM composition, the ability of FT-ICR MS to characterize DOM subpopulations provides unique insight into the mechanisms through which DOM source and environmental processing determine composition and photochemical activity.

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Probe Compounds to Assess the Photochemical Activity of Dissolved Organic Matter

Cited by 247 publications

References 175 publications

Photomineralization mechanism changes the ability of dissolved organic matter to activate cloud droplets and to nucleate ice crystals

Photomineralization mechanism changes the ability of dissolved organic matter to activate cloud droplets and to nucleate ice crystals

Photochemical fate of quaternary ammonium compounds in river water

Relationships Between Dissolved Organic Matter Composition and Photochemistry in Lakes of Diverse Trophic Status

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