Design of an Automated Rapid Vapor Concentrator and Its Application in Nitroaromatic Vapor Sampling
An automated, rapid-cycling vapor concentrator and sample introduction device was designed and evaluated. The device consists of an inert deactivated fused silica capillary sampling loop. The temperature of the loop was manipulated through contact with a cold plate or a hot plate, maintained at pre-selected temperatures with a thermoelectric cooler and heating cartridge, respectively. The position of the loop was controlled with a stepper motor under microprocessor control. The low mass of the loop permit its rapid cooling and heating. This permits efficient trapping of adsorptive vapors such as the nitroaromatics from the air stream and also allows rapid and quantitative transfer of the trapped analytes to the detection system. The use of at thermoelectric cooler permits variable trapping temperatures and increased sampling selectivity without the use of cumbersome cryogenic fluids. Chemically inert sampling train surfaces prevent analyte loss due to irreversible adsorption and cross contamination between samples. The device was evaluated for rapid analysis of nitroaromatic and chlorinated aromatic vapors from air stream at trace concentrations with a selective electron capture detection system. Trapping efficiencies of > 95 percent can be readily obtained with the device for nitroaromatics at ppb and sub ppb concentrations.
M. Gehrke et al., "Design of an Automated Rapid Vapor Concentrator and Its Application in Nitroaromatic Vapor Sampling," Proceedings of SPIE: Detection and Remediation Technologies for Mines and Minelike Targets V, SPIE -- The International Society for Optical Engineering, Apr 2000.
The definitive version is available at http://dx.doi.org/10.1117/12.396219
Mechanical and Aerospace Engineering
Article - Conference proceedings
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