electron ionisation

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electron ionisation

The process of molecular ionisation initiated by the interaction of a gas-phase molecule with an energetic electron. The beam of electrons is emitted from a heated metal filament in the source; the electrons are then accelerated through a potential difference of 70 V. The collision between the molecule and the electron causes ejection of an electron from the molecule (M), and produces a radical molecular ion with the unpaired electron (M•).
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References in periodicals archive ?
Another main factor that could have influenced the observed signal was the energy distribution of the electron population because excitation of O-atom and [N.sub.2] to the targeted excited states was accomplished though electron impact excitation from high-energy free electrons present in the discharge.
The electron impact parameter standard values of broadening for this line (0.085 nm) [9].
Gas chromatography-mass spectrometry (GC-MS) was performed using a Shimadzu GC-17A/QP-5000 (Kyoto, Japan) in the electron impact mode.
Analytical methods to detect volatile NA are based on gas chromatography (GC) with a thermal energy analyser (TEA) [16, 21, 22], with mass spectrometry (MS) by electron impact ionization (EI) [23-25], and with mass spectrometry by chemical ionization [26-29].
Mass spectra were acquired from m/z 50 to m/z 600 in electron impact mode and from m/z 100 to m/z 600 in negative ion chemical ionization (NICI) mode.
The Commission has also approved a project with the Comenius University in Bratislava, Slovakia, to measure electron impact ionisation and excitation cross-sections of hydrocarbon molecules (by using crossed-beam experimental techniques), including the measurement of electron attachment cross-sections of hydrogen compounds.
Micromass launched its new GCT, a TOF MS detector for electron impact, chemical, and field ionization of volatile/semi-volatile compounds.
Mass spectrometric analysis was based on electron impact mass spectrometry (EI-MS) and high resolution electron impact mass spectrometry (HR-EI-MS).
The ionizer is a filament assembly that generates ions directly inside the trap through electron impact of gas molecules.
The BenchTOF-dx mass spectrometer from ALMSCO International, a division of Markes International Ltd., is a compact reflectron time-of-flight instrument that generates classical electron impact ionization (EI) spectra for gas chromatography and comprehensive GCxGC applications.

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