Abstract
Abstract A condensation reaction between aldehydes and a primary amine on the surface of particulate matter created and suspended in a laboratory environment has been studied. The methodology developed for these studies made use of a non-volatile chromophore, 1,8-diaminonaphthalene, as the starting amine which facilitated detection of the starting and product compounds. This reactive chromophore was located on glycerol droplets, saturated salt water droplets, or salt particles that were levitated in an electrodynamic balance. Following an exposure of the levitated droplets/particles to the vapor of different aldehyde compounds, the droplets/particles were deposited onto a stainless steel plate and the reaction products, imines, were characterized using laser desorption ionization mass spectrometry. The starting compound, 1,8-diaminonaphthalene and the imine reaction product compounds were detected as molecular radical cations. The rate of the heterogeneous/multiphase reaction between the amine and benzaldehyde was measured to be 9×10−19 cm3 molecule−1 s−1 on glycerol droplets, which makes the rate of imine formation comparable with amine consumption via ozone or hydroxyl radical under conditions of slightly elevated aldehyde concentrations. As such, imine formation via a heterogeneous/multiphase reaction could occur under certain conditions in the troposphere. This reaction on particulate matter reduces the hydrophilic character of the product compound relative to the starting compounds, and the implications of this class of reactions with respect to the toxic properties of suspended particles in the troposphere are briefly speculated upon.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call