Secondary organic aerosol formation from the photochemical reaction of isoprene with OH radical

Abstract

Using smog chamber,Secondary organic aerosol (SOA) formation from the reaction of isoprene with OH radical was studied.Gaseous products were determined by proton-transfer-reaction mass spectrometer (PTR-MS) while SOA concentration and size distribution were determined by EEPS3090.The dominating gaseous products were methacrolein (MAC)/methyl vinyl ketone (MVK),acetaldehyde,formaldehyde,methanol,formic acid/ethanol,glycollic aldehyde,methylglyoxal,acetone/propionaldehyde and so on.The highest production of MAC/MVK and acetaldehyde were 13.78% 37.72% and 5.38% 9.34% (based on C).SOA production and its mean size increased with increasing reacted isoprene.When the gas phase products were stable,the SOA yields were in the range of 5.6% 11.7% and the particle sizes were from 22 nm to 165 nm.