Activated carbon as adsorbent for alkyllead in air

A method is described for the determination of alkyllead in air with activated carbon as adsorbent. The main factor affecting the adsorption capacity of the activated carbon for alkyllead was the concentration of hydrocarbons in the sampled air, as these were also adsorbed. Particulate inorganic lead was collected on a membrane filter in front of the adsorbent. The alkyllead was extracted from the adsorbent into hot nitric acid, and the concentration determined by electrothermal atomic absorption spectrometry. The detection limit was 0.002 μg Pb m^?3 (sample volume 1 m³), and precision was 9.5% r.s.d. at 2.1 μg Pb m^?3 alkyllead. The method was used to monitor exposure of gasoline tank truck drivers to alkyllead. During the filling of tank trucks with leaded gasoline, alkyllead concentrations from 1 to 750 μg Pb m^?3 were found in the drivers' breathing zone, but most were well below the Norwegian TLV of 75 μg Pb m^?3.