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  2. Mass spectral interpretation - Wikipedia

    en.wikipedia.org/wiki/Mass_spectral_interpretation

    Mass spectral interpretation is the method employed to identify the chemical formula, characteristic fragment patterns and possible fragment ions from the mass spectra. [1] [2] Mass spectra is a plot of relative abundance against mass-to-charge ratio. It is commonly used for the identification of organic compounds from electron ionization mass ...

  3. Fragmentation (mass spectrometry) - Wikipedia

    en.wikipedia.org/wiki/Fragmentation_(mass...

    In mass spectrometry, fragmentation is the dissociation of energetically unstable molecular ions formed from passing the molecules mass spectrum.These reactions are well documented over the decades and fragmentation patterns are useful to determine the molar weight and structural information of unknown molecules.

  4. Mass spectrometry - Wikipedia

    en.wikipedia.org/wiki/Mass_spectrometry

    Ion mobility spectrometry-mass spectrometry (IMS/MS or IMMS) is a technique where ions are first separated by drift time through some neutral gas under an applied electrical potential gradient before being introduced into a mass spectrometer. [43] Drift time is a measure of the collisional cross section relative to the charge of the ion.

  5. Mass spectrum - Wikipedia

    en.wikipedia.org/wiki/Mass_spectrum

    A mass spectrum is a histogram plot of intensity vs. mass-to-charge ratio (m/z) in a chemical sample, [1] usually acquired using an instrument called a mass spectrometer. Not all mass spectra of a given substance are the same; for example, some mass spectrometers break the analyte molecules into fragments ; others observe the intact molecular ...

  6. Sample preparation in mass spectrometry - Wikipedia

    en.wikipedia.org/wiki/Sample_preparation_in_mass...

    The first and most important step in sample preparation for mass spectrometry is determining what phase the sample needs to be in. Different ionization methods require different sample phases. Solid phase samples can be ionized through methods such as field desorption , plasma-desorption , fast atom bombardment , and secondary-ion ionization .

  7. Selected reaction monitoring - Wikipedia

    en.wikipedia.org/wiki/Selected_reaction_monitoring

    The ion is selected in the second mass spectrometry stage MS2 then undergoes further fragmentation to form ion D + which is selected in the third mass spectrometry stage MS3 and detected. Multiple reaction monitoring ( MRM ) is the application of selected reaction monitoring to multiple product ions from one or more precursor ions, [ 3 ] [ 4 ...

  8. Liquid chromatography–mass spectrometry - Wikipedia

    en.wikipedia.org/wiki/Liquid_chromatography...

    The mass spectrum can be used to determine the mass of the analytes, their elemental and isotopic composition, or to elucidate the chemical structure of the sample. [5] MS is an experiment that must take place in gas phase and under vacuum (1.33 * 10 −2 to 1.33 * 10 −6 pascal).

  9. Chlorine dioxide - Wikipedia

    en.wikipedia.org/wiki/Chlorine_dioxide

    The molecule ClO 2 has an odd number of valence electrons, and therefore, it is a paramagnetic radical. It is an unusual "example of an odd-electron molecule stable toward dimerization" (nitric oxide being another example). [5] A unit cell of the orthorhombic ClO 2 crystal shown in an arbitrary direction.