A system and method for collecting sub-hourly ambient particulate matter
samples at flow rates of 170-260 L/min is suitable for either on- or
off-line near-real-time multielement analysis by graphite furnace atomic
absorption spectrometry and other techniques for which a sample in slurry
form is advantageous. Condensational growth of water vapor was used to
grow fine particles by steam injection. The grown droplets are
concentrated using a virtual impactor, then separated from the airstream
using a real impactor. The particles are collected in a liquid slurry
which is hydraulically delivered to sample vials every 30 minutes for
offline analysis, or directly delivered into the graphite furnace for
atomic absorption spectrometry analysis.
