oa Differences in δ13C Values of Levoglucosan from Lignite and Biomass Low-Temperature Combustion

We showed that stable carbon levoglucosan-specific isotope analysis may be one possible way to determine the relative contributions from coal combustion versus biomass burning sources. PM samples were collected from low-temperature burning/smoldering of Miocene lignites from Poland and basket willow (Salix viminalis L.) representative of biomass.

The calculated levoglucosan δ13C values of xylites varied from −23.6 to−21.6‰, while for detritic coal samples they ranged from −24.2 to −23.1‰, with means of −22.7 and −23.7‰, respectively. The calculated levoglucosan δ13C value of baske twillow wood was−27.1‰. Values of willow wood mixtures with xylite varied from−25.8 to−23.4‰ (with an increasing proportion of xylite), while values of mixtures of willow and detritic coal ranged from−26.9 to−24.6‰ (with an increasing proportion of detritic coal). The hopanoid distributions characteristic for low-temperature lignite/peat burning, with a predominance of 22R-α,β-homohopane, ββ-hopanes and hopenes, as well as low or very low values of the homohopane index, were observed in smoke PM from most lignite samples and absent in the basket willow sample. Thus, the relatively high content of hopanes (with the occurrence of 22R-α,β-homohopane, ββ-hopanes and hopenes) in atmospheric PM samples can be treated as additional tracers of lignite combustion.