A micro gas chromatograph for high-speed determinations of explosive vapors

Progress toward a gas chromatographic microsystem (muGC) designed for rapid determinations of trace-level vapor concentrations of nitroaromatic explosives is presented. This muGC, dubbed INTREPID, is being designed to capture, preconcentrate, inject, separate, and detect vapor samples. Its components and operating parameters are being optimized to differentiate nitro-aromatic explosives from potential interferences in complex mixtures on the basis of chromatographic retention times and sensor-array response patterns. Here, we describe the performance of several components and subsystems. We demonstrate that TNT can be separated from nine relevant interferences in < 40 s, microcolumn and nanoparticle-coated chemiresistor-array detector can be coupled effectively, and that unique array response patterns for TNT can be obtained. We present the PC-board-mounted INTREPID prototype for the first time.