μChemLab? – Twenty Years of Developing CBRNE Detection Systems with Low False Alarm Rates

摘要

Gas Chromatography (GC) is routinely used in the laboratory to temporally separate chemical mixtures into theirconstituent components for improved chemical identification. This paper will provide a overview of more than twentyyears of development of one-dimensional field-portable micro GC systems, highlighting key experimental results thatillustrate how a reduction in false alarm rate (FAR) is achieved in real-world environments. Significantly, we will alsopresent recent results on a micro two-dimensional GC (micro GCxGC) technology. This ultra-small system consists ofmicrofabricated columns, NanoElectroMechanical System (NEMS) cantilever resonators for detection, and a valve-basedstop-flow modulator. The separation of a 29-component polar mixture in less than 7 seconds is demonstrated along withpeak widths in the second dimension ranging from 10-60 ms. For this system, a peak capacity of just over 300 wascalculated for separation in about 6 s. This work has important implications for field detection, to drastically reduce FARand significantly improve chemical selectivity and identification. This separation performance was demonstrated with theNEMS resonator and bench scale FID. But other detectors, suitably fast and sensitive can work as well. Recent researchhas shown that the identification power of GCxGC-FID can match that of GC-MS. This result indicates a path to improvedsize, weight, power, and performance in micro GCxGC systems outfitted with relatively non-specific, lightweightdetectors. We will briefly discuss the performance of possible options, such as the pulsed discharge helium ionizationdetector (PDHID) and miniature correlation ion mobility spectrometer (mini-CIMS).