Investigation On Electrostatic Migratory Behavior And Physiochemical Characteristics Of Inhalable Particles

It is well known that inhalable particles are harmful to environment and people's health. More and more attention had been paid to measurement and control of these particles. In this paper, Quartz crystal microbalance (QCM) was developed for passive and size-selective sampling and continuous measuring of mass concentration and size distributionWith the electrostatic effect, the particles were deposited onto the plane. And electrostatic deposition behavior was related to the electric intensity and the size of the particles. The results showed that the particles smaller than lOp.m could be sampled when the voltage was at 3.0kV; while those larger than 30p.m were sampled when the voltage was raised to 5.0kV. This was the basis of passive and size-selective sampling of inhalable particles.Keeping sampling temperature, voltage and relative humidity invariable, the sensitivity reached its maximum when the distance of point-to-plane was 7.0mm. Passive sampling coefficient of a certain size range particles was determined at a constant voltage. Mass concentration of inhalable particles was calculated by sampling coefficient and the change of frequency. Controlling the voltage at 3.0kV and 5.0kV, size distribution of two kinds of particles that were smaller than 10?tm and SOprn, was respectively measured.Microgram grade inhalable particles sampled by QCM were dissolved with deionized water and digested with microwave oven. Then, ion chromatography was introduced to analyze water-solved ions, such as F, CF, NOT, S042. RSD for these jig/L grade ions was less than 6.7%.