Sequential differential mobility analyzer and method of using same

摘要

The invention is essentially a sequential (“DMA”) apparatus using a novel arrangement of at least three electrodes and at least two block electrodes to produce a DMA apparatus having at least two sequential DMA regions between pairs of adjacent electrode walls within the same housing. This apparatus is used to improve the transfer of particles into the subsequent DMA region without a vacuum or pump, and to improve the separation of target particles from non-target particles and concentration and collection of the target particles.

主权项

1. A differential mobility analyzer apparatus for analyzing a sample of aerosol particles or for separating and concentrating aerosol particles, the apparatus comprising:
a housing serving as a conduit for the flow of aerosol particles, the housing defining a housing pathway for the flow of the particles along a longitudinal axis; an inlet providing the particles into the housing, the particles flowing longitudinally downstream; a first conduit located laterally interior of the housing, the first conduit defining a first pathway for the flow of the particles longitudinally downstream; a second conduit located laterally interior of the first conduit, the second conduit defining a second pathway for the flow of the particles longitudinally downstream; a first outer wall of the first conduit, the first outer wall separating the housing pathway from the first pathway wherein a voltage is applied to the first outer wall; and a first inner wall of the second conduit, the first inner wall separating the first pathway from the second pathway wherein a voltage is applied to the first inner wall; and a first block electrode that is electrically charged wherein the block electrode at least partially obstructs the second pathway.