chemical ionization , CI (Abkürzung)

It is a form of chemical ionization which takes place at atmospheric pressure.

Chemical ionization for gas phase analysis is either positive or negative.

Electron capture can be used in conjunction with chemical ionization.

Chemical ionization is a lower energy process than electron ionization.

Chemical ionization was developed in the 1960s.

In addition, she developed methods of chemical ionization for spectral interpretation of trace compounds.

In chemical ionization a reagent gas, typically methane or ammonia is introduced into the mass spectrometer.

Self chemical ionization occurs when the reagent ion is an ionized form of the analyte.

Electron ionization and chemical ionization are used for gases and vapors.

Chemical ionization (CI) is an ionization technique used in mass spectrometry.

In chemical ionization, ions are produced through the reaction of ions of a reagent gas with other species.

It is a chemical ionization free interface (unless operated intentionally) with accurate reproduction of the expected isotope ion abundances.

Negative chemical ionization (NCI)

In chemical ionization sources, the analyte is ionized by chemical ion-molecule reactions during collisions in the source.

In negative chemical ionization (NCI) the reagent gas decreases the impact of the free electrons on the target analyte.

Atmospheric pressure chemical ionization (APCI)

Chemical ionization, with methane as the reactant gas, and selective ion recording of the ion peaks at m/z 363 and 364 was used.

In positive chemical ionization (PCI) the reagent gas interacts with the target molecule, most often with a proton exchange.

The interface is most often an electrospray ion source or variant such as a nanospray source; however atmospheric pressure chemical ionization interface is also used.

Chemical ionization in an atmospheric pressure electric discharge is called atmospheric pressure chemical ionization.

One of the main benefits of using chemical ionization is that a mass fragment closely corresponding to the molecular weight of the analyte of interest is produced.

There are several ionization methods: electron impact, chemical ionization, electrospray, fast atom bombardment, matrix assisted laser desorption ionization, and others.

Ion-attachment ionization is similar to chemical ionization in which a cation is attached to the analyte molecule in a reactive collision:

The HSID Atmospheric-pressure chemical ionization interface, utilizes heated, laminar flow in order to reduce sample contamination, providing enhanced sensitivity compared to traditional types of interfaces.

In order to see a response by negative chemical ionization, the analyte must be capable of producing a negative ion (stabilize a negative charge) for example by electron capture ionization.