Stable Carbon Isotope Ratio Analysis of Anhydrosugars in Biomass Burning Aerosol Particles from Source Samples

Abstract

A new method for stable carbon isotope ratio analysis of anhydrosugars from biomass burning aerosol particle source filter samples was developed by employing Thermal Desorption--2 Dimensional Gas Chromatography--Isotope Ratio Mass Spectrometry (TD-2DGC-IRMS). Compound specific isotopic measurements of levoglucosan, mannosan, and galactosan performed by TD-2DGC-IRMS in a standard mixture show good agreement with isotopic measurements of the bulk anhydrosugars, carried out by Elemental Analyzer--Isotope Ratio Mass Spectrometry (EA-IRMS). The established method was applied to determine the isotope ratios of levoglucosan, mannosan, and galactosan from source samples collected during combustion of hard wood, softwood, and crop residues. δ(13)C values of levoglucosan were found to vary between -25.6 and -22.2‰, being higher in the case of softwood. Mannosan and galactosan were detected only in the softwood samples showing isotope ratios of -23.5‰ (mannosan) and -25.7‰ (galactosan). The isotopic composition of holocellulose in the plant material used for combustion experiments was determined with δ(13)C values between -28.5 and -23.7‰. The difference in δ(13)C of levoglucosan in biomass burning aerosol particles compared to the parent fuel holocellulose was found to be -1.89 (±0.37)‰ for the investigated biomass fuels. Compound specific δ(13)C measurements of anhydrosugars should contribute to an improved source apportionment.

Elucidating carbonaceous aerosol sources by the stable carbon δ13CTC ratio in size-segregated particles

“…Fine fraction particles predominately consist of OM (Organic Matter) (Bressi et al, 2013); thus, organic carbon from traffic emissions can lead to the lower δ 13 C TC values in fine fraction particles, particularly during autumn-winter time in urban areas. Coarse fraction particles had more positive δ 13 C TC values in this study than the fine fraction particles, thus having a good agreement with reported data (Cachier et al, 1985;Garbaras et al, 2009;Sang et al, 2012). The enrichment in 13 C of the coarse particles can be a result of contribution of carbonates that come from a variety of sources in urban areas: rural soils, street and non-paved road dust (Lopez-Veneroni, 2009;Manoli et al, 2002), and construction activities (e.g., re-suspension of mineral dust) (Dimitriou and Kassomenos, 2014;Keuken et al, 2013).…”

“…Cascade impactors were used to study fine particulate matter in numerous studies (Cabada et al, 2004;Chow et al, 2008;Fang et al, 2006;Huang et al, 2004;Yao et al, 2001;Keywood et al, 1999;Kleeman et al, 2008;Liu et al, 2008;Lü et al, 2012;Plaza et al, 2011;Singh et al, 2003); however, only a few of them attempted to study stable carbon isotope ratio values (Cachier et al, 1985;Garbaras et al, 2009;Sang et al, 2012;Wang et al, 2012) that are a useful tool to identify the sources of particulate matter. Furthermore, δ 13 C TC values can provide a useful starting point in detecting and distinguishing carbonaceous aerosol particles.…”

The importance of non-fossil sources in carbonaceous aerosols in a megacity of central China during the 2013 winter haze episode: A source apportionment constrained by radiocarbon and organic tracers

“…The composition of anhydrosugars (Gal, Man, and Lev) provides diagnostic information regarding the type of biomass (Sang et al, 2012). In this study, anhydrosugars were composed primarily of Lev (92% ± 0.6%), with the rest being Man (5% ± 0.5%) and Gal (3% ± 0.2%).…”

Source Apportionment Using Radiocarbon and Organic Tracers for PM2.5 Carbonaceous Aerosols in Guangzhou, South China: Contrasting Local- and Regional-Scale Haze Events

“…(OC/Lev) bb ratios vary with different biomass types (hardwood, softwood, and annual plants, such as grass) (SI Table S2) due to differences in cellulose content. On the basis of the ratios of the three anhydrosugar isomers, 28 biomass-burning aerosols in Guangzhou mainly originate from hardwood combustion (SI Table S2). Therefore, an (OC/Lev) bb ratio of 7.76 ± 1.47 (SI Table S2) was used to calculate OC bb in this study.…”

“…In this work, different carbon species (WIOC, WSOC, and EC) and water-soluble ions were measured, as well as three anhydrosugar isomers, i.e., levoglucosan (Lev), galactosan (Gal), and mannosan (Man), which are good markers of aerosols derived from biomass burning. 27,28 Eight samples representing different atmospheric conditions were selected to further analyze the 14 C content of WIOC, WSOC, and EC, as well as secondary organic aerosol (SOA) tracers that could directly reflect atmospheric reactions.…”