SMOG CHAMBER STUDY OF ACENAPHTHENE: GAS/PARTICLE PARTITION MEASUREMENTS OF THE PRODUCTS FORMED BY REACTION WITH THE OH RADICAL

Abstract

We studied the gas/particle partitioning of the products of the reaction of acenaphthene with the OH radical in a 10 m ³ smog chamber using multichannel, annular, diffusion denuders. The results showed that most of the products are predominantly in the particulate phase. Only four compounds, such as nitroacenaphthene, preferred the gas phase. We expect that the majority of the oxidation products would be adsorbed onto atmospheric particles. A comparison of solid-phase microextraction (SPME) and denuder sampling showed that the SPME syringe takes a representative sample of both gaseous and particulate phases and therefore cannot be used to determine the gas/particle partitioning ratios of the products. Another interesting result of this study showed that methanol cannot be used for sample extraction because this solvent reacts with some of the oxidation products of acenaphthene (probably the epoxide compounds) to produce artifacts that could lead to a misinterpretation of the actual atmospheric reactions.

Keywords:

• acenaphthene
• gas/particle partition ratio
• radical reactions
• smog chamber

Notes

^a DB, from database searching.

^b BP, from basic principles.