Pneumatoamperometric determination of sulfur dioxide in air on ppb level

A simple device for the determination of sulfur dioxide at ppb concentrations in air is described. The device is composed of an enrichment unit operating continuously on the basis of gas extraction into polydisperse aerosol of a liquid transferring sulfur dioxide from liter amount of air into microliter amount of liquid. The analyte is determined pneumatoamperically from the concentrate on a gold-plated porous Teflon electrode. The detection limit is 0.3 ppb (v), i.e. 0.87 microgram/m3 of sulfur dioxide, the linear range covers several orders of magnitude. The analytical response is obtained few tenths of seconds after the gas contaminated with sulfur dioxide has entered the enrichment unit.