Search results
Results From The WOW.Com Content Network
When a certain threshold voltage has been reached the slightly rounded tip inverts and emits a jet of liquid. This is called a cone-jet and is the beginning of the electrospraying process in which ions may be transferred to the gas phase. It is generally found that in order to achieve a stable cone-jet a slightly higher than threshold voltage ...
[24] This process leads to the buildup of an electric surface charge, expressed usually in C/m 2. This surface charge creates an electrostatic field that then affects the ions in the bulk of the liquid. This electrostatic field, in combination with the thermal motion of the ions, creates a counter charge, and thus screens the electric surface ...
Diagram of an electrostatic analyzer in the hemispherical geometry. Only ions of a selected energy pass through to the detector. As opposed to TOF analyzers, electrostatic analyzers achieve ion energy resolution using electrostatic deflectors to direct only ions of a particular energy range into a collector, while all other ions are redirected.
Electrostatic spray ionization (ESTASI) is an ambient ionization method for mass spectrometry (MS) analysis of samples located on a flat or porous surface, or inside a microchannel. It was developed in 2011 by Professor Hubert H. Girault ’s group at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. [ 1 ]
Feynman diagram for the process of double ionization in an atom through re-scattering mechanism. The re-scattering model in Kuchiev's version (Kuchiev's model) is quantum mechanical. The basic idea of the model is illustrated by Feynman diagrams in figure a. First both electrons are in the ground state of an atom.
Electrostatic spray ionization (ESTASI) involved the analysis of samples located on a flat or porous surface, or inside a microchannel. A droplet containing analytes is deposited on a sample area, to which a pulsed high voltage to is applied. When the electrostatic pressure is larger than the surface tension, droplets and ions are sprayed.
Schematic of field desorption ionization with emitter at left and mass spectrometer at right. Field desorption (FD) is a method of ion formation used in mass spectrometry (MS) in which a high-potential electric field is applied to an emitter with a sharp surface, such as a razor blade, or more commonly, a filament from which tiny "whiskers" have formed.
Ionic potential is the ratio of the electrical charge (z) to the radius (r) of an ion. [1]= = As such, this ratio is a measure of the charge density at the surface of the ion; usually the denser the charge, the stronger the bond formed by the ion with ions of opposite charge.