Low-leakage gas sample-injection system for gas chromatography in harsh environments

We report on a microinjector for gas chromatography, whose specificity is to be able to sustain the harsh environment of natural gas. This device integrates six low-leak microvalves made from polyetheretherketone membranes on silicon substrate. We present the design, operation principle, and results of intrinsic characterizations of the microinjector, as well as its behavior in a compact gas chromatograph. The microinjector dimensions are 7 mm × 3 mm × 1.2 mm. Precise injection of 250 nL sample volumes is achieved thanks to leakage levels of less than 4 nl/s, combined with a small injection time. Transition time is 25 ms.