A FastGC Proton-Transfer-Reaction Quadrupole Ion Guide Time-of-Flight (PTR-QiTOF) Mass Spectrometer
Poster Mar 09, 2015
Alfons Jordan1, Lukas Märk1, Jens Herbig1, Christian Lindinger1, Rene Gutmann1, Lukas Fischer1, Eugen Hartungen1, Simone Jürschik1, Gernot Hanel1, Philipp Sulzer1, Tilmann D. Märk1,2
State-of-the-art Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-TOFMS) instruments perform with sensitivities of typically 100 - 200 cps/ppbv. Here we present a novel PTR-TOFMS setup that utilizes a Quadrupole ion guide (Qi) instead of a common lens system for a much more effective transport of ions into the mass spectrometer. With measurement data obtained by introducing certified gas standards into the PTR-QiTOF we demonstrate that its sensitivity is up to 4,700 cps/ppbv, i.e. about 25 times more than the best instruments so far. Such outstandingly high sensitivities are of particular importance in fields of application where time per analysis is limited, e.g. flux measurements in atmospheric chemistry and mouth- or nosespace analysis in food and flavor research. Notably, in these fields the chemical environment is usually very complex so that even the selectivity of a high-resolution mass spectrometer is not sufficient. Monoterpenes, for example, are important compounds in atmospheric chemistry as well as in food and flavor research and appear at m/z 137 (protonated monoterpene). Therefore, we coupled the novel PTR-QiTOF with a FastGC inlet system and analyzed manuka tea and spruce resin, respectively. In the figure below one can see that indeed in normal direct-injection mode all monoterpenes appear indistinguishably at m/z 137. However, after switching the inlet system to FastGC mode the monoterpenes get separated according to their retention times and are easily distinguishable. The FastGC run takes less than 60 s and can even be considerably reduced to quasi-real-time by applying a sophisticated GC pulsing method (patent pending).