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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 ...
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 ...
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.
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.
Trapped fragment ions or their ion-molecule reaction products can be re-excited for multistage mass spectrometry (MS n). [5] If the excitation is not applied on the resonant frequency, but at a slightly off-resonant frequency, the ions will alternately be excited and de-excited, permitting multiple collisions at low collision energy.
In the selected ion flow tube mass spectrometer, SIFT-MS, ions are generated in a microwave plasma ion source, usually from a mixture of laboratory air and water vapor. . From the formed plasma, a single ionic species is selected using a quadrupole mass filter to act as "precursor ions" (also frequently referred to as primary or reagent ions in SIFT-MS and other processes involving chemical ...
When treated with hydrogen sulfide, polysulfanes are formed as indicated in the following idealized formula: 2 H 2 S + S 2 Cl 2 → H 2 S 4 + 2 HCl. It reacts with ammonia to give tetrasulfur tetranitride as well as heptasulfur imide (S 7 NH) and related S−N rings S 8−n (NH) n (n = 2, 3). [9] 16 NH 3 + 6 S 2 Cl 2 → S 4 N 4 + S 8 + 12 NH 4 Cl
A mass chromatogram is a representation of mass spectrometry data as a chromatogram, where the x-axis represents time and the y-axis represents signal intensity. [1] The source data contains mass information; however, it is not graphically represented in a mass chromatogram in favor of visualizing signal intensity versus time.