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  2. Chemical ionization - Wikipedia

    en.wikipedia.org/wiki/Chemical_ionization

    Chemical ionization for gas phase analysis is either positive or negative. [12] Almost all neutral analytes can form positive ions through the reactions described above. In order to see a response by negative chemical ionization (NCI, also NICI), the analyte must be capable of producing a negative ion (stabilize a negative charge) for example ...

  3. Atmospheric-pressure chemical ionization - Wikipedia

    en.wikipedia.org/wiki/Atmospheric-pressure...

    In the negative mode, [M−H] − ions are produced by either proton abstraction, or [M+X] − ions are produced by anion attachment. Most work on the APCI-MS analysis has been in positive mode. In the positive mode, when the discharge current of corona discharge is 1-5 μA on the nebulized solvent, N 2 gas molecules are excited and ionized ...

  4. Air ioniser - Wikipedia

    en.wikipedia.org/wiki/Air_ioniser

    Cations are positive ions missing one or more electrons, resulting in a net positive charge. Some commercial air purifiers are designed to generate negative ions. Another type of air ioniser is the electrostatic discharge (ESD) ioniser (balanced ion generator) used to neutralise static charge.

  5. Direct analysis in real time - Wikipedia

    en.wikipedia.org/wiki/Direct_analysis_in_real_time

    In positive ion mode, DART produces predominantly protonated molecules [M+H] + and in negative-ion mode deprotonated molecules [M-H] −. Both negative and positive modes of DART provides relatively simple mass spectra. Depending on the type of analyte, other species may be formed, such as multiple charged adducts. DART is categorized as a soft ...

  6. Negative air ions - Wikipedia

    en.wikipedia.org/wiki/Negative_air_ions

    Negative air ions (NAI) are important air component, generally referring to the collections of negatively charged single gas molecules or ion clusters in the air. They play an essential role in maintaining the charge balance of the atmosphere. [1] [2] The main components of air are molecular nitrogen and oxygen.

  7. Ionization - Wikipedia

    en.wikipedia.org/wiki/Ionization

    Ionization (or ionisation specifically in Britain, Ireland, Australia and New Zealand) is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecule is called an ion.

  8. Ionic atmosphere - Wikipedia

    en.wikipedia.org/wiki/Ionic_atmosphere

    The more concentrated the solution, the closer these negative ions are to the positive ion and thus the greater the resistance experienced by the positive ion. This influence on the speed of an ion is known as the "Asymmetry effect" because the ionic atmosphere moving around the ion is not symmetrical; the charge density behind is greater than ...

  9. Ion - Wikipedia

    en.wikipedia.org/wiki/Ion

    Forming an ionic bond, Li and F become Li + and F − ions. An ion (/ ˈ aɪ. ɒ n,-ən /) [1] is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge ...