Behavior of Acrolein and Other Aldehydes in Ambient Air of Osaka City

Measurement of acrolein and other aldehydes in ambient air was carried out at the Research Institute of Environment, Agriculture, and Fisheries in Osaka city from May 11 to 19 in 2007. The aldehydes were collected as their derivatives of O-(4-cyanoethoxbenzyl) hydroxylamine (CNET), and determined by liquid chromatography/tandem-mass spectrometry (LC/MS/MS). The concentrations of acrolein, 0.04∼0.49μg/m3, showed the positive correlations with nitrogen monoxide (NO), nitrogen dioxide (NO2), nitrogen oxides (NOx), carbon monoxide (CO), and non-methane hydrocarbons (NMHC). On the other hand, it showed the negative correlation with oxidant (Ox). These results suggested that acrolein exhausted from motor vehicles, increased in the morning and midnight, and was easily decomposed under sunlight by photochemical reaction. Formaldehyde showed a different behavior from acrolein. It showed the positive correlation with oxidant (Ox) generated with the photochemical reaction, and thus increased in the daytime.