Transformation of Polycyclic Aromatic Hydrocarbons During Sampling in Ambient Air by Exposure to Different Oxidized Nitrogen Compounds and Ozone

摘要

It has been reported earlier that individual PAH can undergo chemical transformation when exposed to gases such as NO sub 2 and O sub 3 . In this paper the possibility of artifact formation due to such transformations during sampling in ambient air is discussed. Addition of 1 ppM NO sub 2 or 120 ppB HNO sub 3 (g) during ambient air sampling caused degradation of reactive PAH on particles and formation of the corresponding monitor-PAH. The degradation due to NO sub 2 exposure increased in the presence of acid on the particles. Addition of 100 ppB HNO sub 2 (g) had no detectable effect. The results indicate that NO sub 2 concentrations within the range normally formed in urban air may cause degradation of some reactive PAH. In the case of O sub 3 addition, degradation was obtained in one of the experiments only. (ERA citation 08:047266)