Ammonium CI-Orbitrap: a tool for characterizing the reactivity of oxygenated organic molecules

Atmospheric measurement techniques, Journal Year: 2024, Volume and Issue: 17(17), P. 5413 - 5428

Published: Sept. 13, 2024

Abstract. Oxygenated organic molecules (OOMs) play an important role in the formation of atmospheric aerosols. Due to various analytical challenges with respect measuring vapors, uncertainties remain regarding and fate OOMs. The chemical ionization Orbitrap (CI-Orbitrap) mass spectrometer has recently been shown be a powerful technique that is able accurately identify gaseous compounds due its greater resolution. Here, we present ammonium-ion-based CI-Orbitrap (NH4+-Orbitrap) as capable wide range performance NH4+-Orbitrap compared state-of-the-art spectrometers, including nitrate-ion-based pressure interface coupled time-of-flight (NO3--LTOF), new generation proton transfer reaction-TOF (PTR3-TOF), iodide-based CI-TOF equipped Filter Inlet for Gases AEROsols (I−-CIMS). instruments were deployed simultaneously Cosmic Leaving OUtdoors Droplets (CLOUD) chamber at European Organization Nuclear Research (CERN) during CLOUD14 campaign 2019. Products generated from α-pinene ozonolysis under experimental conditions measured by spectrometers. was widest OOMs (i.e., O ≥ 2), less-oxidized species highly oxygenated (HOMs). Excellent agreement found between NO3--LTOF characterizing HOMs PTR3-TOF monomeric species. OOM concentrations estimated using calibration factors derived high time-series correlations side-by-side measurements. As other spectrometry techniques used this campaign, detection sensitivity greatly affected relative humidity, which may related changes efficiency and/or multiphase chemistry. Overall, study shows NH4+-ion-based chemistry associated resolution analyzer can measure almost all inclusive compounds. result, it now possible cover entire compounds, lead better understanding oxidation processes.

Language: Английский

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Multiphysical description of atmospheric pressure interface chemical ionisation in MION2 and Eisele type inlets

Atmospheric measurement techniques, Journal Year: 2024, Volume and Issue: 17(20), P. 5989 - 6001

Published: Oct. 16, 2024

Abstract. Chemical ionisation inlets are fundamental instrument components in chemical mass spectrometry (CIMS). However, the sample gas and reagent ion trajectories often understood only a general qualitative manner. Here, we evaluate two atmospheric pressure interface (MION2 Eisele type inlet) with 3D computational fluid dynamics physicochemical models regarding estimate their efficiencies of production, delivery from source volume into ion–molecule mixing region, interaction between ions target molecules. The validated by laboratory measurements quantitatively reproduce observed sensitivities to tuning parameters, including currents changes spectra. study elucidates how different transport reactions proceed within studied inlets, where space charge can already be relevant at concentrations as low 107 cm−3, compares investigated inlet models. provide insights operate will help development future that further enhance capability CIMS.

Language: Английский

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Intrinsic Chemical Drivers of Organic Aerosol Volatility: From Experimental Insights to Model Predictions

Journal of Geophysical Research Atmospheres, Journal Year: 2024, Volume and Issue: 129(21)

Published: Nov. 5, 2024

Abstract Accurately predicting the volatilities of molecules in aerosols is challenging but crucial for understanding atmospheric effects aerosols. We used negative and positive ion electrospray ionization Fourier‐transform cyclotron resonance mass spectrometry (FT‐ICR MS) to identify differences molecular compositions gas particle phase samples from urban atmosphere. aimed intrinsic chemical parameters that determine predict organic aerosol volatility. found higher average weights, carbon percentages, double bond equivalents (DBE) lower O/C ratios oxygen percentages than phase. identified DBE, which display a significant correlation with volatility, as key parameter. proposed improve previous model volatility by incorporating DBE new variant; result showed this subsequently improved accuracy model, particularly compounds minimal or no heteroatoms (0–2) such hydrocarbons (CH). The revised offers insights into contributions carbon, nitrogen, oxygen, sulfur atoms diverse could be applied our distributions volatile ambient air.

Language: Английский

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Effect of Different Sources and Meteorological Processes on the Variability of VOC Composition in a Metropolitan City of Western India During Summer Season

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(9)

Published: May 10, 2025

Abstract High time‐ and mass‐resolution measurements of volatile organic compounds (VOCs) using proton‐transfer‐reaction‐time flight‐mass spectrometry were conducted in Ahmedabad metropolitan city India during the summer (April–May) 2014. The concentrations aromatic VOCs lower than winter (January 2014), whereas acetaldehyde acetone levels almost same both seasons. Higher isoprene (2.14 ± 0.66 ppb(v)) monoterpenes (0.34 0.13 ppb) indicate enhanced biogenic emissions. Automotive emissions major sources anthropogenic VOCs, with higher emission ratios oxygenated for heavy‐duty light‐duty vehicles, respectively. Daytime VOC 2–3 times winter, indicating greater contributions from secondary sources. daytime relative acetone, acetaldehyde, increased by ∼35%–45% compared to winter. OH‐reactivity was highest among measured much Oxygenated contribute significantly ozone formation potential seasons, while only summer. box model results at different NO x ‐VOC combinations, observed simulated data, show that reductions can effectively reduce rates concentrations. study reveals reduction emissions, biogenic/secondary become increasingly important atmospheric processes tropical urban regions. Our analysis will be valuable developing mitigation policies control primary pollutants areas India.

Language: Английский

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The synergistic role of sulfuric acid, ammonia and organics in particle formation over an agricultural land

Environmental Science Atmospheres, Journal Year: 2023, Volume and Issue: 3(8), P. 1195 - 1211

Published: Jan. 1, 2023

Agriculture provides people with food, but poses environmental challenges. Via comprehensive observations on an agricultural land at Qvidja in Southern Finland, we were able to show that soil-emitted compounds (mainly ammonia and amines), together available sulfuric acid, form new aerosol particles which then grow climate-relevant sizes by the condensation of extremely low volatile organic originating from a side production photosynthesis (compounds emitted ground surrounding vegetation). We found intensive local clustering events, particle formation rates 3 nm about 5-10 times higher than typical boreal forest environments, occur around 30% all days. The requirements for these events be clear sky, wind speed accumulate emissions land, particularly ammonia, presence compounds, sufficient gaseous acid. will contribute regional formation. Since is much more effective per surface area producing particles, findings provide insight into participation lands climatic cooling, counteracting warming effects farming.

Language: Английский

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Particle‐Phase Uptake and Chemistry of Highly Oxygenated Organic Molecules (HOMs) From α‐Pinene OH Oxidation

Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 127(16)

Published: Aug. 9, 2022

Abstract Secondary organic aerosol (SOA) forms a major part of the tropospheric submicron particle mass. Still, exact formation mechanisms SOA have remained elusive. It is now admitted that highly oxygenated molecules (HOMs) can contribute to large fraction formation. In this study, we performed set chamber experiments investigate formation, and HOMs uptake processing directly formed by OH‐radical initiated oxidation α ‐pinene under two different seed conditions. Numerous HOM compounds were identified using advanced online offline analytical techniques, grouped into four classes according their behaviors. For first time, individual coefficients ranging from 1.1 × 10 −2 1.5 −1 experimentally determined analyzed resistance model which considers limitations gas‐ and/or particle‐phase processes. This study demonstrates strongly depend on molar mass respective O/C ratio. Results show composition phase state affect initial HOMs. Furthermore, acidity phase‐state significantly enhance subsequent through occurring acidity‐driven reactions reflected in reactive behavior, particularly (NH 4 )HSO conditions, promoting up 3 times higher including oxidized organosulfates (HOOS). Overall, present implies chemical play an important role both early growth newly particles when high.

Language: Английский

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Online detection of airborne nanoparticle composition with mass spectrometry: Recent advances, challenges, and opportunities

TrAC Trends in Analytical Chemistry, Journal Year: 2023, Volume and Issue: 166, P. 117195 - 117195

Published: July 17, 2023

Language: Английский

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An online method for monitoring atmospheric intermediate volatile organic compounds with a thermal desorption-gas chromatography/mass spectrometry

Journal of Chromatography A, Journal Year: 2022, Volume and Issue: 1677, P. 463299 - 463299

Published: July 5, 2022

Language: Английский

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Relative Humidity Impact on Organic New Particle Formation from Ozonolysis of α- and β-Pinene at Atmospherically Relevant Mixing Ratios

Atmosphere, Journal Year: 2023, Volume and Issue: 14(1), P. 173 - 173

Published: Jan. 13, 2023

The impact of relative humidity (RH) on organic new particle formation (NPF) from ozonolysis monoterpenes remains an area active debate. Previous reports provide contradictory results indicating both depression and enhancement NPF under conditions moderate RH, while others do not indicate a potential impact. Only several have suggested that the effect may depend absolute mixing ratio precursor volatile compound (VOC, ppbv). Herein we report RH dark α- β-pinene at ratios ranging 0.2 to 80 ppbv. We show enhances (by factor eight) lowest α-pinene ratio, with very strong dependence 4 22 At higher ratios, plateaus, resulting modest decreases in NPF. In case β-pinene, is enhanced low due combination chemistry, accelerated kinetics, reduced partitioning semi-volatile oxidation products particulate phase. Reduced would limit growth, permitting increased gas-phase concentrations semi- low-volatility products, which could favor

Language: Английский

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Variation in chemical composition and volatility of oxygenated organic aerosol in different rural, urban, and mountain environments

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(4), P. 2607 - 2624

Published: Feb. 28, 2024

Abstract. The apparent volatility of atmospheric organic aerosol (OA) particles is determined by their chemical composition and environmental conditions (e.g., ambient temperature). A quantitative, experimental assessment the respective importance these two factors remains challenging, especially in measurements. We present molecular oxygenated OA (OOA) different rural, urban, mountain environments (including Chacaltaya, Bolivia; Alabama, US; Hyytiälä, Finland; Stuttgart Karlsruhe, Germany; Delhi, India) based on deployments a filter inlet for gases aerosols coupled to high-resolution time-of-flight ionization mass spectrometer (FIGAERO-CIMS). find average larger carbon numbers (nC​​​​​​​) lower oxygen-to-carbon (O : C) ratios at urban sites (nC: 9.8 ± 0.7; O C: 0.76 0.03; ±1 standard deviation) compared rural 8.8 0.6; 0.80 0.05) stations 8.1 0.8; 0.91 0.07), indicative emission sources chemistry. Compounds containing only carbon, hydrogen, oxygen atoms (CHO) contribute most total OOA (79.9 5.2 %), accordance with proximity forested areas (66.2 5.5 % 72.6 4.3 sites). largest contribution nitrogen-containing compounds (CHON) found (27.1 consistent higher NOx levels. Moreover, we parametrize (saturation concentrations, Csat) using information compare it bulk derived from thermal desorption within FIGAERO. differences Csat values up ∼ 3 orders magnitude variation profiles (thermograms) across locations systems. From our study, draw general conclusion that temperature) do not directly affect but rather indirectly influencing chemistry environment thus composition. comprehensive dataset provides results show complex thermodynamics changes during its lifetime atmosphere. conclude generally description suffices predict volatility, least qualitatively. Our study new insights will help guide choices of, e.g., descriptions model frameworks such as air quality models cloud parcel models.

Language: Английский

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