Electron ionization - Wikipedia
The electron ionization time of flight mass spectroscopy (EI-TOF MS) is well suited for analytical and basic chemical physics studies. EI-TOF MS is used to find ionization potentials of molecules and radicals , as well as bond dissociation energies for ions and neutral molecules.
3.1: Electron Ionization - Chemistry LibreTexts
Electron Ionization (EI) is the most common ionization technique used for mass spectrometry. * EI works well for many gas phase molecules, but it does have some limitations. Although the mass spectra are very reproducible and are widely used for spectral libraries, EI causes extensive fragmentation so that the molecular ion is not observed for ...
Electron Ionization Sources: The Basics - Spectroscopy Online
2006年7月1日 · The ion source is the heart of the mass spectrometer. In the ion source, ions are created from gas-phase neutral sample molecules, or preformed ions are extracted from solutions, and then sent into the mass analyzer of the instrument.
Electron Ionization - an overview | ScienceDirect Topics
The basic form of ionization in mass spectrometry is electron ionization (EI), where an electron beam, usually at an energy of 70 eV, collides with the molecules of the sample to transform them into positively charged ions.
Electron Ionization - an overview | ScienceDirect Topics
Ions created by field-induced removal of an electron from the molecule are extracted into the mass spectrometer. Field ionization (FI) is the equivalent process whereby gas-phase molecules are ionized by a high electric potential. These techniques are sometimes applied to relatively large, polymeric molecules but are not commonplace.
NanoLC-EI-MS: Perspectives in Biochemical Analysis - PMC
In contrast, electron ionization mass spectrometry (EI-MS) stands out as a technique practically free of matrix effects, which could be a significant advantage for analyzing biological samples . In EI, ionization occurs in the gas phase, in which the analyte molecules are bombarded with high-energy electrons to produce cationic fragments.
Tracking Molecular Fragmentation in Electron–Ionization Mass ...
2024年2月17日 · Mass spectrometry is a powerful analytical method capable of identifying compounds given a minute amount of material. The fragmentation pattern that results following molecular activation serves as a fingerprint that can be …
Rapid Prediction of Electron–Ionization Mass Spectrometry ...
2019年3月19日 · In response, we present Neural Electron–Ionization Mass Spectrometry (NEIMS), a neural network that predicts the electron–ionization mass spectrum for a given small molecule.