7.2 - Application of High Resolution Ion Mobility Spectrometers for Fast Trace Gas Analysis
- 11. Dresdner Sensor-Symposium 2013
2013-12-09 - 2013-12-11
Dreikönigskirche - Haus der Kirche Dresden
- A. Kirk, M. Allers, P. Cochems, J. Langejuergen, S. Zimmermann - Leibniz Universität Hannover/D
- 127 - 132
Ion mobility spectrometers (IMS) are a widely used tool for fast trace gas detection, generally offering excellent limits of detection (LoD) in a short amount of time, but only mediocre resolution. In this work, we demonstrate an approach to vastly increase the resolution without sacrificing limits of detection or increasing the complexity of the measurement setup. Based on these findings, a compact ion mobility spectrometer with a drift length of less than 10 cm has been constructed. It offers a resolution of above 180 in both positive and negative mode while maintaining detection limits in the pptv range for an averaging time of less than a second. This resolution is e.g. sufficient to separate the two isomers sec-butylamine and tert-butylamine, even though their collision cross sections and therefore drift times differ by less than one percent. Furthermore, analysis of the spectrum of chlorine shows a change in peak shape which could indicate the beginning separation of the two stable isotopes.