Comparison with previous BBOA phase behavior measurements. The observation of two phases is consistent with the results by Gregson et al. who observed two phases in BBOA particles generated from smoldering pine wood in the laboratory and sampling BBOA directly on microscope slides using an impactor and without extraction with a solvent. Visual differences between our samples in Figure The fact that the impacted BBOA in Gregson et al. shows the same phase behaviour as our extracts possibly suggests that a mixture of methanol and water extracted a wide enough range of the compounds in BBOA to accurately describe its phase behaviour.