THE FORMALDEHYDE AND ACETALDEHYDE CONTENT OF ATMOSPHERIC AEROSOL

The present work is concerned with the formaldehyde and acetaldehyde content of atmospheric aerosol. Atmospheric formaldehyde and acetaldehyde present in the gas-phase were collected using C-18 Sep Pak cartridges coated with an acidic solution of 2,4-dinitrophenylhydrazine (DNPH). Aldehydes associated with aerosols were collected on high-vol glass fiber filters. Sixteen source samples were collected during 1-hour periods in two sites located in the city of Salvador, Bahia: a bus station and a tunnel. The results obtained for formaldehyde and acetaldehyde attained values of 109 mu g/m(3) and 167 mu g/m(3) in the gas-phase, and 0.028 mu g/m(3) and 0.055 mu g/m(3) in the aerosol-phase, respectively. Even these small aerosol-phase concentrations are considerably higher than the equilibrium concentration values predicted from the water content of the aerosol, the simultaneously measured gas-phase concentrations, and the respective Henry's constants.