Electron impact ionization (EI) is by far the most commonly used ionization technique in GC–MS. During the first phase, the molecules of a sample are bombarded by high-energy electrons (70 eV). When these electrons pass near neutral molecules, they may pass on sufficient energy to remove ...
The bending vibrational levels of the acetylene cation: A case study of the Renner-Teller effect in a molecule with two degenerate bending vibrations The ionization potential of C 2 H 2 (from the lowest rotational level of the ground state to the lowest rotational level of the cation) is fou...
The ionization energy of N2 (IE = 15.6 eV) also exceeds that of most organic molecules, making N2 ideal for the analysis of a wide range of compounds, as is often required for NTS. In some cases, it may be desirable to select a gas with an ionization energy that lies above that of...
Experimental results for the electron impact ionization of benzene, providing double (DDCS) and triple differential cross sections (TDCS) at the incident energy of 90 eV, measured with a multi-particle momentum spectrometer, are reported in this paper. The most intense ionization channel is assigned...
(sodium chloride) is an ionic compound that includes the cation version of the sodium atom, which has had an electron removed by a process that imparts the ionization energy. Although they aren't created by the same type of ionization because they gain an extra electron, negatively charged ...
In subject area: Chemistry Electron impact mass spectrometry (EI-MS) involves the bombardment of the vaporized metabolite by high-energy electrons (0–100eV), producing a molecular radical cation (M+·) having a mass equivalent to the molecular weight of the compound. ...
The Triple-Differential Cross Section (TDCS) for the Photo Double-Ionization of carbon dioxide molecule to the CO22+X3Σgground state has been measured at 20eV excess energy. In the experiment the coincidence angular distributions of the two photoelectrons, where the direction of one photoelectron...
A small amount of this solution is placed on the laser target. The matrix absorbs energy from the laser pulse and produces plasma that results in vaporization and ionization of analyte molecules. MALDI is used to quantify or determine the molecular weight of peptides, proteins, oligonucleotides, ...
—0.25 mm, df—0.25 μm, carrier gas—helium, injector temperature—270 °C, the initial chromatograph oven temperature—40 °C, heating rate 5 °C/min to 300 °C, followed by isotherm for 10 min; MS parameters: electron ionization with 70eV ionization energy, source temperature—230 °C...
This shift results, on the one hand, in modification of the vibrational parameters and, on the other hand, in deepening the energy level of the tunnelling electron. The above-listed effects are considered in detail below. 2.1. The MO-ADK Model In the MO-ADK model, the tunnel ionization ...