Evidence has accumulated suggesting that acidic ultrafine particles
(AUFPs, particles with a diameter of less than 0.1 μm) may affect
human health. However, related researches lack reliable instruments
to quantify the concentration of AUFPs for further evaluation of their
health effects.
Our novel acidic ultrafine particle measuring device features a
diffusion sampler and a quartz crystal microbalance (QCM) detector
with specially treated crystal oscillators. The device can precisely
measure the concentration of AUFPs. When in operation, both acidic
and non-acidic ultrafine particles are collected and deposited on the
diffusion sampler. While the non-acidic ultrafine particles collected
are removed, the AUFPs react with the crystal oscillators. The QCM
then measures the change in mass and calculates the mass and
number concentrations of AUFPs.