New Chem paper on tracking constituent exchange among suspended aerosol particles

The exchange of constituents between distinct types of aerosols is relevant to many processes important to atmospheric chemistry, combustion, bio-threat detection, and consumer-product formulations. However, because of the high similarity of aerosol mass spectrometer signals, it is difficult to distinguish between different aerosol populations and to track constituent exchange. We have overcome this hurdle by synthesizing deuterium-labeled terpenes as precursors for secondary organic aerosols and studying mixing driven by semi-volatile vapor exchange with particles formed from other unlabeled terpenes as well as toluene. We found that particles from isoprene and α-pinene ozonolysis absorbed vapors rapidly. Particles from limonene ozonolysis showed slower exchange, and particles from β-caryophyllene ozonolysis showed limited exchange. Our results show that molecular exchange among particles from terpene oxidation becomes slower and less extensive as the precursor carbon number increases. The new paper is out in Chem.