Four intensive experimental campaigns were conducted in the Po Valley (Northern Italy) in different seasons through the years 2012 and 2013, in the framework of the“Supersito”project. As a part of astudy on polar tracers in atmospheric PM2.5, the present paper describes the abundances and temporal variations of sugars, as primary biogenic biomarkers, being the major form of photosyntheticallyassimilated carbon in the biosphere. The study includes primary saccharides (glucose, sucrose, arabinose, galactose and mycose), sugar alcohols (arabitol and mannitol) and anhydrosugars (levoglucosan, gal-actosan and mannosan). Strong seasonality was observed with total sugars concentration nearly 10 times higher in the cold seasons than in summer/spring. Also sugar composition profiles varied seasonally, being dominated by anhydrosugars in fall and winter, i.e., levoglucosan followed by mannosanand galactosan. These data indicate that in the cold seasons the biomass combustion for domestic heating is the main sugar source representing nearly 94% of the total saccharides mass measured in PM2.5. Accordingly, glucose, arabinose and galactose show the highest concentrations, since these saccharides are also emitted during theburning process as uncombusted biomass materials. In spring/summer the primary saccharides are dominant in PM2.5, with mannitol as the most abundant, followed by mycose, glucose and ribitol that areemitted by the terrestrial biomass, reflecting the higher sugar production and utilization by theecosystem in the warm seasons. These results were confirmed by investigating other molecular markers, such as low-molecular-weightcarboxylic acids and n-alkane homologs. Principal Component Analysis was applied to the data to extract three PCs that may be attributed to different saccharide sources, such as biomass burning and primary bio aerosol.
Polar organic marker compounds in atmospheric aerosol in the Po Valley during the Supersito campaigns — Part 2: Seasonal variations of sugars
PIETROGRANDE, Maria Chiara;BACCO, Dimitri;VISENTIN, Marco;
2014
Abstract
Four intensive experimental campaigns were conducted in the Po Valley (Northern Italy) in different seasons through the years 2012 and 2013, in the framework of the“Supersito”project. As a part of astudy on polar tracers in atmospheric PM2.5, the present paper describes the abundances and temporal variations of sugars, as primary biogenic biomarkers, being the major form of photosyntheticallyassimilated carbon in the biosphere. The study includes primary saccharides (glucose, sucrose, arabinose, galactose and mycose), sugar alcohols (arabitol and mannitol) and anhydrosugars (levoglucosan, gal-actosan and mannosan). Strong seasonality was observed with total sugars concentration nearly 10 times higher in the cold seasons than in summer/spring. Also sugar composition profiles varied seasonally, being dominated by anhydrosugars in fall and winter, i.e., levoglucosan followed by mannosanand galactosan. These data indicate that in the cold seasons the biomass combustion for domestic heating is the main sugar source representing nearly 94% of the total saccharides mass measured in PM2.5. Accordingly, glucose, arabinose and galactose show the highest concentrations, since these saccharides are also emitted during theburning process as uncombusted biomass materials. In spring/summer the primary saccharides are dominant in PM2.5, with mannitol as the most abundant, followed by mycose, glucose and ribitol that areemitted by the terrestrial biomass, reflecting the higher sugar production and utilization by theecosystem in the warm seasons. These results were confirmed by investigating other molecular markers, such as low-molecular-weightcarboxylic acids and n-alkane homologs. Principal Component Analysis was applied to the data to extract three PCs that may be attributed to different saccharide sources, such as biomass burning and primary bio aerosol.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
