Measurements of alkyllead compounds in the gas and aerosol phase in urban and rural atmospheres.

Alkyllead compounds in the gas and aerosol phase were determined simultaneously in urban and rural atmospheres using gas chromatography--atomic absorption spectroscopy and wet chemical (iodine monochloride) methods. The difference in results between the two methods suggests the presence of vapour-phase tri- (and/or di-)alkyllead in both urban and rural air. Concentrations of 0.06-1.6 and 16-205 ng Pb m-3 were found for vapour-phase organolead compounds other than tetraalkyllead in rural and kerbside urban air, respectively. Tetraalkyllead and trialkyllead compounds were identified in atmospheric aerosols at both sites, but these were found to be present at concentrations less than 1.2% of the total gas-phase alkyllead.