Details
| Original language | English |
|---|---|
| Pages (from-to) | 31-39 |
| Number of pages | 9 |
| Journal | International Journal for Ion Mobility Spectrometry |
| Volume | 15 |
| Issue number | 1 |
| Publication status | Published - 5 Nov 2011 |
Abstract
Ion mobility spectrometry is a well-known method for fast trace gas detection. Detection limits in the very low ppb and even ppt-range, fast response times down to a second and good separation power combined with a reasonable instrumental effort make ion mobility spectrometry more and more attractive. Aiming for higher separation power we investigate the ion specific lifetime of different ion species in a field free reaction region of a drift tube ion mobility spectrometer equipped with a pulsed non-radioactive electron gun. When turning off the electron gun ionization stops and the total ion concentration in the reaction region starts to decrease, while different ion species have different decay times. By varying the time delay between the end of the ionization and the injection pulse transferring all remaining ions of one polarity from the reaction region into the drift region the individual decay times can be measured. Our experimental data show that the lifetime of ion species in a field free reaction region mainly depends on ion-ion-recombination and charge transfer reactions leading to significant lifetime differences. Therefore, short-lived ions can be effectively suppressed in the reaction region by introducing a sufficient time delay between the end of the ionization and the injection pulse. This allows detecting even smallest concentrations of long-lived ions in a complex short-lived background. From our experimental data it can be also concluded that wall losses and the ion transport within the sample gas stream out of the reaction region just play a minor role in the ion loss.
Keywords
- Ion mobility spectrometry, Ion suppression, Ion-ion recombination, Non-radioactive electron source, Pulsed electron gun
ASJC Scopus subject areas
- Chemistry(all)
- Spectroscopy
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In: International Journal for Ion Mobility Spectrometry, Vol. 15, No. 1, 05.11.2011, p. 31-39.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Selective ion suppression as a pre-separation method in ion mobility spectrometry using a pulsed electron gun
AU - Cochems, Philipp
AU - Gunzer, Frank
AU - Langejuergen, Jens
AU - Heptner, Andre
AU - Zimmermann, Stefan
N1 - Funding information: Acknowledgment. This study was supported by the Kanagawa Cancer Research Fund.
PY - 2011/11/5
Y1 - 2011/11/5
N2 - Ion mobility spectrometry is a well-known method for fast trace gas detection. Detection limits in the very low ppb and even ppt-range, fast response times down to a second and good separation power combined with a reasonable instrumental effort make ion mobility spectrometry more and more attractive. Aiming for higher separation power we investigate the ion specific lifetime of different ion species in a field free reaction region of a drift tube ion mobility spectrometer equipped with a pulsed non-radioactive electron gun. When turning off the electron gun ionization stops and the total ion concentration in the reaction region starts to decrease, while different ion species have different decay times. By varying the time delay between the end of the ionization and the injection pulse transferring all remaining ions of one polarity from the reaction region into the drift region the individual decay times can be measured. Our experimental data show that the lifetime of ion species in a field free reaction region mainly depends on ion-ion-recombination and charge transfer reactions leading to significant lifetime differences. Therefore, short-lived ions can be effectively suppressed in the reaction region by introducing a sufficient time delay between the end of the ionization and the injection pulse. This allows detecting even smallest concentrations of long-lived ions in a complex short-lived background. From our experimental data it can be also concluded that wall losses and the ion transport within the sample gas stream out of the reaction region just play a minor role in the ion loss.
AB - Ion mobility spectrometry is a well-known method for fast trace gas detection. Detection limits in the very low ppb and even ppt-range, fast response times down to a second and good separation power combined with a reasonable instrumental effort make ion mobility spectrometry more and more attractive. Aiming for higher separation power we investigate the ion specific lifetime of different ion species in a field free reaction region of a drift tube ion mobility spectrometer equipped with a pulsed non-radioactive electron gun. When turning off the electron gun ionization stops and the total ion concentration in the reaction region starts to decrease, while different ion species have different decay times. By varying the time delay between the end of the ionization and the injection pulse transferring all remaining ions of one polarity from the reaction region into the drift region the individual decay times can be measured. Our experimental data show that the lifetime of ion species in a field free reaction region mainly depends on ion-ion-recombination and charge transfer reactions leading to significant lifetime differences. Therefore, short-lived ions can be effectively suppressed in the reaction region by introducing a sufficient time delay between the end of the ionization and the injection pulse. This allows detecting even smallest concentrations of long-lived ions in a complex short-lived background. From our experimental data it can be also concluded that wall losses and the ion transport within the sample gas stream out of the reaction region just play a minor role in the ion loss.
KW - Ion mobility spectrometry
KW - Ion suppression
KW - Ion-ion recombination
KW - Non-radioactive electron source
KW - Pulsed electron gun
UR - http://www.scopus.com/inward/record.url?scp=84857449192&partnerID=8YFLogxK
U2 - 10.1007/s12127-011-0084-7
DO - 10.1007/s12127-011-0084-7
M3 - Article
AN - SCOPUS:84857449192
VL - 15
SP - 31
EP - 39
JO - International Journal for Ion Mobility Spectrometry
JF - International Journal for Ion Mobility Spectrometry
SN - 1435-6163
IS - 1
ER -