Field testing of a rugged MEMS gas chromatograph prototype: Selective analysis of trace-level TCE vapors in contaminated homes

Abstract

Two fully integrated and automatically controlled MEMS gas chromatographs (µGC) were successfully deployed in the field to monitor trichloroethylene (TCE) at trace-level concentrations (0.6-80 ppb) in homes suffering from vapor intrusion (VI) from surrounding TCE-contaminated soil. Each instrument combines a high-volume sampling module (non-microfabricated) with a microanalytical module consisting of a microfocuser, dual microcolumns, and a chemiresistor array detector. A complete sampling and analytical cycle requires 15-30 min, depending on required sensitivity. Limits of detection as low as 0.02 ppb were achieved. TCE was separated from 45 co-contaminants. Use of the prototypes in fixed-site (temporal TCE fluctuations) and portable operating modes (spatial mapping of TCE) was successfully demonstrated. Good agreement with concentrations determined with standard reference methods was achieved.

Inverse Method For Flow Reconstruction Using Gas Tracers In Building Environments

“…Using a hybrid micro-gas chromatograph, detection capabilities of down to ppt levels (which is extremely low) with a measurement time of few minutes have been reported (Chang et al, 2010). Real-time analysis of air in contaminated homes using two µGC prototypes have also been perfomed (Kim et al, 2011). In this latter study, more than 45 volatile organic compounds (VOC) could be separated in less than one minute.…”