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Penning ionization is a form of chemi-ionization, an ionization process involving reactions between neutral atoms or molecules. [1] [2] The Penning effect is put to practical use in applications such as gas-discharge neon lamps and fluorescent lamps, where the lamp is filled with a Penning mixture to improve the electrical characteristics of the lamps.
Gas phase ion chemistry is a field of science encompassed within both chemistry and physics. It is the science that studies ions and molecules in the gas phase, most often enabled by some form of mass spectrometry. By far the most important applications for this science is in studying the thermodynamics and kinetics of reactions.
A Penning mixture is a mixture of gases that is used in electric gas-discharge lamps. It is defined as a mixture of one inert gas with a minute amount of another gas, one that has lower ionization voltage than the main constituent. It is named after Frans Michel Penning. [1] [2]
Chemi-ionization is the formation of an ion through the reaction of a gas phase atom or molecule with another atom or molecule when the collision energy is below the energy required to ionize the reagents. [1] [2] The reaction may involve a reagent in an excited state [3] or may result in the formation of a new chemical bond.
The DART ion source is a kind of gas-phase ionization, and it requires some sort of volatility of the analyte to support thermally assisted desorption of analyte ions. [14] This limits the size range of the molecules that can be analyzed by DART i.e. m/z 50 to 1200. [1] [15] DART-MS is capable of semi-quantitative and quantitative analysis. To ...
Sample preparation for PI includes first ensuring the sample is in the gas phase. PI ionizes molecules by exciting the sample molecules with photons of light. This method only works if the sample and other components in the gas phase are excited by different wavelengths of light. It is important when preparing the sample, or photon source, that ...
Chemical ionization in an atmospheric pressure electric discharge is called atmospheric pressure chemical ionization (APCI), which usually uses water as the reagent gas. An APCI source is composed of a liquid chromatography outlet, nebulizing the eluent, a heated vaporizer tube, a corona discharge needle and a pinhole entrance to 10 −3 torr ...
The overlaps get quite close at the point where the d-orbitals enter the picture, [50] and the order can shift slightly with atomic number [51] and atomic charge. [52] [h] Starting from the simplest atom, this lets us build up the periodic table one at a time in order of atomic number, by considering the cases of single atoms.