Automated particle collection and analysis. Near-real time measurement of aerosol cerium (III)

Growth of particles by supersaturated vapor condensation followed by impaction-based collection allows efficient collection of atmospheric particles in the micron and submicron range and results in a liquid output stream in which the collected particles are dissolved or suspended. The original apparatus (Anal. Chem., 67, 1995, 71–78) has been substantially improved by obviating the need for a thermoelectrically cooled flow through the maze. The instrument is investigated for its potential to collect and measure metallic constituents in submicron size aerosols. Sodium sulfate aerosols containing traces of Ce (III) sulfate were used as the test aerosol. A fluorometric method was used to measure Ce (III). Excellent collection efficiencies and a limit of detection of 200 fmol m−3 air were observed.