Reply on RC1 DOI Creative Commons
Matthieu Riva

Опубликована: Март 28, 2024

Abstract. Oxygenated organic molecules (OOMs) play an important role in the formation of atmospheric aerosols. Due to various analytical challenges measuring vapors, uncertainties remain and fate OOMs. The chemical ionization Orbitrap mass spectrometer (CI-Orbitrap) has recently been shown be a powerful technique able accurately identify gaseous compounds due its great resolving power. Here we present ammonium ion (NH4+) based CI-Orbitrap as capable wide range performance CI-(NH4+)-Orbitrap was compared with that state-of-the-art spectrometers, including nitrate (NO3−) CI coupled pressure interfaced long time-of-flight (APi-LTOF), new generation proton transfer reaction-TOF (PTR3-TOF), iodide (I−) CI-TOF equipped Filter Inlet for Gases AEROsols (FIGAERO-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 across multiple experimental conditions measured by spectrometers. NH4+-Orbitrap widest OOMs (i.e., O ≥ 2), low oxidized species highly oxygenated volatile (HOM). Excellent agreements found between NO3−-LTOF characterizing HOMs PTR3-TOF less monomeric species. A semi-quantitative information retrieved using calibration factors derived this side-by-side comparison. As other spectrometry techniques used campaign, detection sensitivity is greatly affected relative humidity, which may related changes efficiency and/or multiphase chemistry. Overall, study shows NH4+ ion-based chemistry associated high power analyzer can measure almost all-inclusive compounds. result, it now possible cover entire compounds, lead better understanding oxidation processes.

Язык: Английский

Nontrivial Impact of Relative Humidity on Organic New Particle Formation from Ozonolysis of cis-3-Hexenyl Acetate DOI Open Access
Austin C. Flueckiger,

Christopher N. Snyder,

Giuseppe A. Petrucci

и другие.

Air, Год журнала: 2023, Номер 1(4), С. 222 - 236

Опубликована: Окт. 17, 2023

The impact of relative humidity (RH) on organic new particle formation (NPF) from the ozonolysis biogenic volatile compounds (BVOCs) remains an area active debate. Previous reports provide contradictory results, indicating both depression and enhancement NPF under conditions high RH. Herein, we report RH dark cis-3-hexenyl acetate (CHA), a green-leaf (GLV) emitted by vegetation. We show that inhibits this BVOC, essentially shutting it down at levels > 1%. While mechanism for inhibition unclear, demonstrate is likely not due to increased losses CHA humid chamber walls. New oxidation products dominant are proposed that, based estimated vapor pressures (VPs), should enhance NPF; however, possible phase concentration these low-volatility sufficient initiate NPF. Furthermore, reaction C3-excited state Criegee intermediates (CIs) with water may lead small carboxylic acids do contribute This hypothesis supported experiments quaternary O3 + α-pinene systems, which showed decreases in total α-pinene-derived ~0% subsequent recovery elevated

Язык: Английский

Процитировано

1
Predicting Atmospheric Water-Soluble Organic Mass Reversibly Partitioned to Aerosol Liquid Water in the Eastern United States DOI
Marwa M.H. El-Sayed, Siddharth S. Parida, Prashant Shekhar

и другие.

Environmental Science & Technology, Год журнала: 2023, Номер 57(46), С. 18151 - 18161

Опубликована: Ноя. 12, 2023

Water-soluble organic matter (WSOM) formed through aqueous processes contributes substantially to total atmospheric aerosol, however, the impact of water evaporation on particle concentrations is highly uncertain. Herein, we present a novel approach predict amount evaporated mass induced by sample drying using multivariate polynomial regression and random forest (RF) machine learning models. The fine WSOM was monitored during three consecutive summers in Baltimore, MD (2015, 2016, 2017). dependent relative humidity (RH), concentrations, isoprene NOx/isoprene ratios. Different models corresponding each class were fitted (trained tested) data from 2015 2016 while model validation performed summer 2017 data. Using coefficient determination (R2) root-mean-square error (RMSE), it concluded that an RF with 100 decision trees had best performance (R2 0.81) lowest normalized mean (NME < 1%) leading low uncertainties. feature importance for calculated be 0.55, 0.2, 0.15, 0.1 RH levels, ratios, respectively. thus used summertime organics Yorkville, Georgia, Centerville, Alabama 2013, Results presented herein have implications measurements rely analysis interpretation sets elucidate their complex behavior.

Язык: Английский

Процитировано

1
Comment on amt-2023-149 DOI Creative Commons
Dandan Li, Dongyu Wang, Lucía Caudillo

и другие.

Опубликована: Фев. 5, 2024

Abstract. Oxygenated organic molecules (OOMs) play an important role in the formation of atmospheric aerosols. Due to various analytical challenges measuring vapors, uncertainties remain and fate OOMs. The chemical ionization Orbitrap mass spectrometer (CI-Orbitrap) has recently been shown be a powerful technique able accurately identify gaseous compounds due its great resolving power. Here we present ammonium ion (NH4+) based CI-Orbitrap as capable wide range performance CI-(NH4+)-Orbitrap was compared with that state-of-the-art spectrometers, including nitrate (NO3−) CI coupled pressure interfaced long time-of-flight (APi-LTOF), new generation proton transfer reaction-TOF (PTR3-TOF), iodide (I−) CI-TOF equipped Filter Inlet for Gases AEROsols (FIGAERO-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 across multiple experimental conditions measured by spectrometers. NH4+-Orbitrap widest OOMs (i.e., O ≥ 2), low oxidized species highly oxygenated volatile (HOM). Excellent agreements found between NO3−-LTOF characterizing HOMs PTR3-TOF less monomeric species. A semi-quantitative information retrieved using calibration factors derived this side-by-side comparison. As other spectrometry techniques used campaign, detection sensitivity is greatly affected relative humidity, which may related changes efficiency and/or multiphase chemistry. Overall, study shows NH4+ ion-based chemistry associated high power analyzer can measure almost all-inclusive compounds. result, it now possible cover entire compounds, lead better understanding oxidation processes.

Язык: Английский

Процитировано

0
Reply on RC2 DOI Creative Commons
Matthieu Riva

Опубликована: Март 28, 2024

Abstract. Oxygenated organic molecules (OOMs) play an important role in the formation of atmospheric aerosols. Due to various analytical challenges measuring vapors, uncertainties remain and fate OOMs. The chemical ionization Orbitrap mass spectrometer (CI-Orbitrap) has recently been shown be a powerful technique able accurately identify gaseous compounds due its great resolving power. Here we present ammonium ion (NH4+) based CI-Orbitrap as capable wide range performance CI-(NH4+)-Orbitrap was compared with that state-of-the-art spectrometers, including nitrate (NO3−) CI coupled pressure interfaced long time-of-flight (APi-LTOF), new generation proton transfer reaction-TOF (PTR3-TOF), iodide (I−) CI-TOF equipped Filter Inlet for Gases AEROsols (FIGAERO-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 across multiple experimental conditions measured by spectrometers. NH4+-Orbitrap widest OOMs (i.e., O ≥ 2), low oxidized species highly oxygenated volatile (HOM). Excellent agreements found between NO3−-LTOF characterizing HOMs PTR3-TOF less monomeric species. A semi-quantitative information retrieved using calibration factors derived this side-by-side comparison. As other spectrometry techniques used campaign, detection sensitivity is greatly affected relative humidity, which may related changes efficiency and/or multiphase chemistry. Overall, study shows NH4+ ion-based chemistry associated high power analyzer can measure almost all-inclusive compounds. result, it now possible cover entire compounds, lead better understanding oxidation processes.

Язык: Английский

Процитировано

0
Reply on RC1 DOI Creative Commons
Matthieu Riva

Опубликована: Март 28, 2024

Abstract. Oxygenated organic molecules (OOMs) play an important role in the formation of atmospheric aerosols. Due to various analytical challenges measuring vapors, uncertainties remain and fate OOMs. The chemical ionization Orbitrap mass spectrometer (CI-Orbitrap) has recently been shown be a powerful technique able accurately identify gaseous compounds due its great resolving power. Here we present ammonium ion (NH4+) based CI-Orbitrap as capable wide range performance CI-(NH4+)-Orbitrap was compared with that state-of-the-art spectrometers, including nitrate (NO3−) CI coupled pressure interfaced long time-of-flight (APi-LTOF), new generation proton transfer reaction-TOF (PTR3-TOF), iodide (I−) CI-TOF equipped Filter Inlet for Gases AEROsols (FIGAERO-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 across multiple experimental conditions measured by spectrometers. NH4+-Orbitrap widest OOMs (i.e., O ≥ 2), low oxidized species highly oxygenated volatile (HOM). Excellent agreements found between NO3−-LTOF characterizing HOMs PTR3-TOF less monomeric species. A semi-quantitative information retrieved using calibration factors derived this side-by-side comparison. As other spectrometry techniques used campaign, detection sensitivity is greatly affected relative humidity, which may related changes efficiency and/or multiphase chemistry. Overall, study shows NH4+ ion-based chemistry associated high power analyzer can measure almost all-inclusive compounds. result, it now possible cover entire compounds, lead better understanding oxidation processes.

Язык: Английский

Процитировано

0