Free amino acid quantification in cloud water at the Puy de Dôme station (France)

• DOI: 10.5194/acp-22-2467-2022
• Publication Date: 2022-02-23T12:53:59Z
• Authors: Pascal Renard; Maxence Brissy; Florent Rossi; Martin Leremboure; Saly Jaber; Jean-Luc Baray; Angelica Bianco; Anne-Marie Delort; Laurent Deguillaume
• Keywords: Alanine

Abstract. Eighteen free amino acids (FAAs) were quantified in cloud water sampled at the Puy de Dôme station (PUY – France) during 13 events. This quantification has been performed without concentration or derivatization, using liquid chromatography hyphened to mass spectrometry (LC-MS) and standard addition method correct for matrix effects. Total concentrations of FAAs (TCAAs) vary from 1.2 7.7 µM, Ser (serine) being most abundant AA (23.7 % on average) but with elevated deviation, followed by glycine (Gly) (20.5 %), alanine (Ala) (11.9 asparagine (Asn) (8.7 leucine/isoleucine (Leu/I)​​​​​​​ (6.4 %). The distribution AAs among events reveals high variability. TCAA constitutes between 0.5 4.4 dissolved organic carbon measured samples. is scarce, results agree few studies that investigated this aqueous medium. environmental variability assessed through a statistical analysis. work shows are correlated time spent air masses within boundary layer, especially over sea surface before reaching PUY. microphysical properties' fluctuation does not explain our samples, confirming previous We finally sources atmospheric processes potentially prevailing presence certain initial relative biological matrices (proteins extracted bacterial cells mammalian cells, example) could dominance Ala, Gly, Leu/I. composition aquatic organisms (i.e., diatom species) also analysis hygroscopicity indicates higher contribution (80 hydrophilic neutral, revealing fact other (hydrophobic) less favorably incorporated into droplets. Finally, aging evaluated calculating lifetimes considering their potential transformation medium biotic abiotic (mainly oxidation) processes. concentrated encountered samples present longest lifetimes, dominant ones clearly efficiently transformed atmosphere, explaining low concentrations. However, cannot fully several complexity bio-physico-chemical occurring multiphase environment.