Sugar like compounds in PM2.5 at three rural background sites in Central Europe

Abstract

Sugar like substances are usually small but important part of organic aerosol being often tracers for individual aerosol sources. Twelve hours samples (day and night) collected during winter and summer campaigns at three Central European rural background sites were utilized to characterize PM2.5 aerosol using complex set of analytical methods. Here we report concentrations of sugars, sugar like alcohols and sugar anhydrides.PM2.5 samplings were performed during February–March and July–August 2021 at three sites, National Atmospheric Observatory Košetice – CZ (NAOK, N 49°35′, E 15°05′; 534 m a.s.l.), Frýdlant – CZ (N 50°94′, E 15°07′; 366 m a.s.l.) and Melpitz –DE (N 51°32', E 12°56'; 86 m a.s.l.). Each site was equipped with high volume Digitel sampler using sampling flow rate 500 l/min. Cut parts of the filter were extracted with ultrapure water and the extracts were analysed using HPAE-PAD analysis and Thermo Scientific 5000+ system for sugar-like substances using a method based on Iinuma et al. 2009.The concentrations of sugar like substances were dominated by levoglucosan in winter at all sites, with 0.32±0.29 µg/m3 at Košetice, 0.21±0.13 µg/m3 at Frýdlant, and 0.15±0.13 µg/m3 at Melpitz. Mannosan/levoglucosan median ratio was the highest at Košetice (0.23) and lowest at Frýdlant (0.18).The summer concentrations of sugar like substances were more evenly distributed in several major substances with concentrations one order lower in comparison to concentrations of levoglucosan in winter. The concentrations of individual sugars, sugar alcohols and sugar anhydrides were relatively evenly distributed, but some differences between the sites were found. The average sums of sugars were the highest of all categories at all sites, but while the sugar alcohols were the second highest in Melpitz, the content of sugar anhydrides was at the second place at Frýdlant and Košetice in summer. Acknowledgements:This work was supported within a German-Czech cooperation in the TRACE project funded by the GACR under grant 20-08304J and by DFG under grant 431895563, also by the MEYS of the Czech Republic under grants ACTRIS-CZ LM2018122 and ACTRIS-CZ RI (CZ.02.1 .01 / 0.0 / 0.0 / 16_013 / 0001315), and European Union's Horizon 2020 research and innovation program ACTRIS IMP (871115).