Articles | Volume 15, issue 2
Atmos. Chem. Phys., 15, 845–865, 2015
Atmos. Chem. Phys., 15, 845–865, 2015

Research article 23 Jan 2015

Research article | 23 Jan 2015

Characterization of biomass burning emissions from cooking fires, peat, crop residue, and other fuels with high-resolution proton-transfer-reaction time-of-flight mass spectrometry

C. E. Stockwell1, P. R. Veres3,2, J. Williams4, and R. J. Yokelson1 C. E. Stockwell et al.
  • 1University of Montana, Department of Chemistry, Missoula, MT, USA
  • 2Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
  • 3Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
  • 4Max Planck Institute for Chemistry, Atmospheric Chemistry Department, 55128 Mainz, Germany

Abstract. We deployed a high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) to measure biomass-burning emissions from peat, crop residue, cooking fires, and many other fire types during the fourth Fire Lab at Missoula Experiment (FLAME-4) laboratory campaign. A combination of gas standard calibrations and composition sensitive, mass-dependent calibration curves was applied to quantify gas-phase non-methane organic compounds (NMOCs) observed in the complex mixture of fire emissions. We used several approaches to assign the best identities to most major "exact masses", including many high molecular mass species. Using these methods, approximately 80–96% of the total NMOC mass detected by the PTR-TOF-MS and Fourier transform infrared (FTIR) spectroscopy was positively or tentatively identified for major fuel types. We report data for many rarely measured or previously unmeasured emissions in several compound classes including aromatic hydrocarbons, phenolic compounds, and furans; many of these are suspected secondary organic aerosol precursors. A large set of new emission factors (EFs) for a range of globally significant biomass fuels is presented. Measurements show that oxygenated NMOCs accounted for the largest fraction of emissions of all compound classes. In a brief study of various traditional and advanced cooking methods, the EFs for these emissions groups were greatest for open three-stone cooking in comparison to their more advanced counterparts. Several little-studied nitrogen-containing organic compounds were detected from many fuel types, that together accounted for 0.1–8.7% of the fuel nitrogen, and some may play a role in new particle formation.

Short summary
We used a high-resolution proton-transfer-reaction time-of-flight mass spectrometer to measure emissions from peat, crop residue, cooking fires, etc. We assigned > 80% of the mass of gas-phase organic compounds and much of it was secondary organic aerosol precursors. The open cooking emissions were much larger than from advanced cookstoves. Little-studied N-containing organic compounds accounted for 0.1-8.7% of the fuel N and may influence new particle formation.
Final-revised paper