Composition of organic compounds from low-temperature burning of lignite and their application as tracers in ambient air. (June 2020)

• Record Type: Journal Article
• Authors: Rybicki, Maciej; Marynowski, Leszek; Simoneit, Bernd R.T.
• Is Part Of: Chemosphere. Volume 249(2020)
• Publication Date: 2020-06
• Subjects: Lignite tracers -- Organic aerosols -- Coal -- Levoglucosan -- Tocopherols -- Hopanes; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.126087
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Levoglucosan, a product from thermal decomposition of cellulose, is widely known as an organic tracer of biomass burning, but has also been reported from coal smoke particulate matter (PM) including lignites. This study provides direct evidence that levoglucosan is generated not only during low-temperature burning/smoldering of xylite, but also from other lignite types including detritic and detroxylitic brown coals from Poland. Moreover, only trace amounts of mannosan and galactosan have been detected in PM of lignite smoke. The hopanes in lignite smoke PM comprise the thermodynamically unstable ββ -hopanes and hopenes, with values of the homohopane index 22S/(22S + 22R) ranging from 0.02 to 0.12. This is characteristic for immature organic matter, and combined with the presence of anhydrosaccharides can be used as tracers for lignite combustion in ambient air. Furthermore, almost all Miocene lignite smoke PM samples contain α-, β-, γ-, and δ-tocopherols, and prist-1-ene. This is the first report of the occurrence of all four tocopherol isomers in the geological record (in lignite extracts) and in lignite smoke PM samples. Lower α-tocopherol is observed for the lignite burn-test samples than in the corresponding lignite extracts, probably due to partial chain degradation to prist-1-ene during combustion. Highlights: Low-temperature combustion of lignite produces significant amounts of levoglucosan. Mannosan and galactosan are present in trace concentrations mainly in xylite smoke PM. All lignite smoke PM samples contain thermodynamically less stable hopanes. Hopanes are lignite burning tracers in samples with high levoglucosan concentrations. First report of all four tocopherol isomers in lignite extracts and their smoke PM.