Molecular Characterization of Cloud Water Samples Collected at the Puy de Dôme (France) by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

Cloud droplets contain dynamic and complex pools of highly heterogeneous organic matter, resulting from the dissolution of both water-soluble organic carbon in atmospheric aerosol particles and gas-phase soluble species, and are constantly impacted by chemical, photochemical, and biological transformations. Cloud samples from two summer events, characterized by different air masses and physicochemical properties, were collected at the Puy de Dôme station in France, concentrated on a strata-X solid-phase extraction cartridge and directly infused using electrospray ionization in the negative mode coupled with ultrahigh-resolution mass spectrometry. A significantly higher number (n = 5258) of monoisotopic molecular formulas, assigned to CHO, CHNO, CHSO, and CHNSO, were identified in the cloud sample whose air mass had passed over the highly urbanized Paris region (J1) compared to the cloud sample whose air mass had passed over remote areas (n = 2896; J2). Van Krevelen diagrams revealed that lignins/CRAM-like, aliphatics/proteins-like, and lipids-like compounds were the most abundant classes in both samples. Comparison of our results with previously published data sets on atmospheric aqueous media indicated that the average O/C ratios reported in this work (0.37) are similar to those reported for fog water and for biogenic aerosols but are lower than the values measured for aerosols sampled in the atmosphere and for aerosols produced artificially in environmental chambers.

Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions

“…Then, with this configuration, one year of calculation corresponds to 5.6 × 10 6 trajectory points. LACYTRAJ has been first used for stratosphere-troposphere exchange studies [30], and then for many other applications such as long-range inter-hemispheric transport of carbon monoxide [31], interaction between the mixing layer and the free troposphere [32], transport of subtropical cirrus clouds [33], or air mass determination of Cloud Water Samples at Puy de Dôme [34]…”

Cézeaux-Aulnat-Opme-Puy De Dôme: a multi-site for the long term survey of the tropospheric composition and climate change

“…Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has also been used to identify a wide spectrum of organic compounds (up to 5000 assigned molecular formula) that have been shared into several classes depending on their H/C and O/C ratio (Bianco et al, 2018(Bianco et al, , 2019a.…”

“… addressing a long-term variability approach in 2004 and 2014 (Deguillaume et al, 2014;Marinoni et al, 2004),  the innovative dimension of biological processes (Amato et al, 2005),  the recent use of high resolution mass spectrometry to address the complex organic molecular characterization (Bianco et al, 2018(Bianco et al, , 2019a.…”

“…back-trajectories of the air masses that reach the PUY station for each cloud event were also calculated to confirm the classification (Bianco et al, 2018). This cloud database has been recently complemented by measurements of trace metals that help to evaluate the impact of anthropogenic and natural sources on the cloud and to better discriminate the origin of the air masses (Bianco et al, 2017).…”

Cloud Occurrence Frequency at Puy de Dôme (France) Deduced from an Automatic Camera Image Analysis: Method, Validation, and Comparisons with Larger Scale Parameters

“…Long-term chemical and biological composition are also investigated [10][11][12], with the objective to classify clouds based on their chemical properties and analyze their backward trajectories. Specific field campaigns are regularly organized, where clouds are sampled and analyzed [13,14].…”