Influence of ionization volume and sample gas flow rate on separation power in gas chromatography-ion mobility spectrometry

verfasst von
Tim Kobelt, Martin Lippmann, Jannik Wuttke, Hanno Wessel, Stefan Zimmermann
Abstract

In this work, the influence of the sample gas flow rate and the ionization region volume of an ion mobility spectrometer (IMS) used as a detector in gas chromatography (GC) on GC-IMS peak shape has been investigated. Therefore, a drift tube IMS with a field-switching ion shutter, a defined ionization region volume and an ultra-violet radiation source was used. To identify the influence of the sample gas flow rate entering the ionization region (equals the GC carrier gas flow rate if no further make-up gas is used) and the ionization region volume on peak broadening and signal intensity, different sample volumes as they would elute from a GC were tested at a variety of sample gas flow rates at a given ionization region volume. The results clearly show that for low sample gas flow rates a depletion of sample molecules in the ionization region leads to a significant decrease in effective detector volume but also to reduced signal intensities. Therefore, for optimal performance of a GC-IMS, the optimal operating point of the GC should match the flow range, where the IMS provides the best compromise between signal-to-noise ratio and peak broadening.

Organisationseinheit(en)
Fachgebiet Sensorik und Messtechnik
Typ
Artikel
Journal
Journal of Chromatography A
Band
1713
Anzahl der Seiten
8
ISSN
0021-9673
Publikationsdatum
04.01.2024
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Analytische Chemie, Biochemie, Organische Chemie
Elektronische Version(en)
https://doi.org/10.1016/j.chroma.2023.464506 (Zugang: Geschlossen)