TY  - JOUR
A1  - Zühlke, Martin
A1  - Zenichowski, Karl
A1  - Riebe, Daniel
A1  - Beitz, Toralf
A1  - Löhmannsröben, Hans-Gerd
T1  - Subambient pressure electrospray ionization ion mobility spectrometry
T2  - International journal for ion mobility spectrometry : official publication of the International Society for Ion Mobility Spectrometry
N2  - The pressure dependence of sheath gas assisted electrospray ionization (ESI) was investigated based on two complementary experimental setups, namely an ESI-ion mobility (IM) spectrometer and an ESI capillary - Faraday plate setup housed in an optically accessible vacuum chamber. The ESI-IM spectrometer is capable of working in the pressure range between 300 and 1000 mbar. Another aim was the assessment of the analytical capabilities of a subambient pressure ESI-IM spectrometer. The pressure dependence of ESI was characterized by imaging the electrospray and recording current-voltage (I-U) curves. Qualitatively different behavior was observed in both setups. While the current rises continuously with the voltage in the capillary-plate setup, a sharp increase of the current was measured in the IM spectrometer above a pressure-dependent threshold voltage. The different character can be attributed to the detection of different species in both experiments. In the capillary-plate experiment, a multitude of charged species are detected while only desolvated ions attribute to the IM spectrometer signal. This finding demonstrates the utility of IM spectrometry for the characterization of ESI, since in contrast to the capillary-plate setup, the release of ions from the electrospray droplets can be observed. The I-U curves change significantly with pressure. An important result is the reduction of the maximum current with decreasing pressure. The connected loss of ionization efficiency can be compensated by a more efficient transfer of ions in the IM spectrometer at increased E/N. Thus, similar limits of detection could be obtained at 500 mbar and 1 bar.
KW  - Ion mobility spectrometry
KW  - Electrospray ionization
KW  - Subambient pressure
KW  - Imaging
Y1  - 2017
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/46615
SN  - 1435-6163
SN  - 1865-4584
VL  - 20
SP  - 47
EP  - 56
PB  - Springer
CY  - Heidelberg
ER  -