Abstract: This technology is a method and apparatus for the semi-continuous measurement of the concentration of constituents of airborne particles which couples a laminar flow, water condensation particle collector to a microfluidic device for assay of particle chemical composition by electrophoresis. The technology has been used for the assay of sulfates, nitrates, chlorides, and organic acids contained in fine and submicrometer atmospheric particles. For these compounds the apparatus and method described is capable of one-minute time resolution at concentrations at the level of micrograms of analyte species per cubic meter of air. Extension to other analytes is possible.

Abstract: A system and method for particle enlargement with continuously wetted wicks includes a container into which a flow of particle-laden air is introduced in a laminar manner through an inlet and to an outlet. The container has a first section, a second section and a third section though which the particle-laden air flows between the inlet and the outlet. The temperature of the second section is warmer than that of the first section at the inlet and the third section at the outlet. In one embodiment, a continuous wick spanning an interior wall of the first second, second section and third section, said wick being capable of internally transporting liquid water along its length is provided.

Abstract: A particle charging method and apparatus are provided. An ion source is applied to a particle laden flow. The flow is introduced into a container in a laminar manner. The container has at least a first section, a second section and a third section. The first section includes wetted walls at a first temperature. A second section adjacent to the first section has wetted walls at a second temperature T2 greater than the first temperature T1. A third section adjacent to the second section has dry walls provided at a temperature T3 equal to or greater than T2. Additional water removal and temperature conditioning sections may be provided.

Abstract: This technology is a method and apparatus for the semi-continuous measurement of the concentration of constituents of airborne particles which couples a laminar flow, water condensation particle collector to a microfluidic device for assay of particle chemical composition by electrophoresis. The technology has been used for the assay of sulfates, nitrates, chlorides, and organic acids contained in fine and submicrometer atmospheric particles. For these compounds the apparatus and method described is capable of one-minute time resolution at concentrations at the level of micrograms of analyte species per cubic meter of air. Extension to other analytes is possible.