Characterization of free L- and D-amino acids in size-segregated background aerosols over the Ross Sea, Antarctica

Matteo Feltracco; Roberta Zangrando; Elena Barbaro; Silvia Becagli; Ki-Tae Park; Marco Vecchiato; Laura Caiazzo; Rita Traversi; Mirko Severi; Carlo Barbante; Andrea Gambaro

doi:10.1016/j.scitotenv.2023.163070

Characterization of free L- and D-amino acids in size-segregated background aerosols over the Ross Sea, Antarctica

Sci Total Environ. 2023 Jun 25:879:163070. doi: 10.1016/j.scitotenv.2023.163070. Epub 2023 Mar 27.

Authors

Affiliations

¹ Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino, 155 - 30172 Venice Mestre (VE), Italy. Electronic address: matteo.feltracco@unive.it.
² Institute of Polar Sciences, National Research Council (CNR-ISP), Via Torino, 155 - 30172 Venice Mestre (VE), Italy; Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino, 155 - 30172 Venice Mestre (VE), Italy.
³ Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, 50019 Florence, Italy; Institute of Polar Sciences, National Research Council (CNR-ISP), Via Torino, 155 - 30172 Venice Mestre (VE), Italy.
⁴ Korea Polar Research Institute (KOPRI), Incheon 21990, South Korea.
⁵ ENEA Laboratory of Observations and Measurements for the Environment and Climate, Rome, Italy.
⁶ Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino, 155 - 30172 Venice Mestre (VE), Italy; Institute of Polar Sciences, National Research Council (CNR-ISP), Via Torino, 155 - 30172 Venice Mestre (VE), Italy.

PMID: 36990237
DOI: 10.1016/j.scitotenv.2023.163070

Abstract

The study of airborne chemical markers is crucial for identifying sources of aerosols, and their atmospheric processes of transport and transformation. The investigation of free amino acids and their differentiation between the L- and D- enantiomers are even more important to understand their sources and atmospheric fate. Aerosol samples were collected with a high-volume sampler with cascade impactor at Mario Zucchelli Station (MZS) on the coast of the Ross Sea (Antarctica) for two summer campaigns (2018/19 and 2019/20). The total mean concentration of free amino acids in PM10 was 4 ± 2 pmol m-3 for both campaigns and most of free amino acids were distributed in fine particles. The coarse mode of airborne D-Alanine and dimethylsufoniopropionate in seawater showed a similar trend during both Antarctic campaigns. Thus, the study of D/L Ala ratio in fine, coarse and PM10 fractions indicated the microlayer as the local source. This paper demonstrated that free amino acids follow the trend of DMS and MSA release occurred in the Ross Sea, confirming their applicability as markers for phytoplankton bloom also in paleoclimatic studies.

Keywords: Aerosol; Amino acids; Antarctica; Phytoplankton bloom.