Search results
Results From The WOW.Com Content Network
(Schematics of a typical en:mass spectrometer Public domain Public domain false false This image is in the public domain in the United States because it only contains materials that originally came from the United States Geological Survey , an agency of the United States Department of the Interior .
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.
A mass-selecting quadrupole and collision quadrupole with time-of-flight device as the second mass selection stage is a hybrid known as a quadrupole time-of-flight mass spectrometer (QTOF MS). [ 8 ] [ 9 ] Quadrupole-quadrupole-time-of-flight (QqTOF) configurations are also possible and used especially the mass spectrometry of peptides and other ...
Both, the first mass analyzer and the collision cell are continuously exposed to ions from the source, in a time independent manner. [4] It is once the ions move into the third mass analyzer that time dependence becomes a factor. [4] The first quadrupole mass filter, Q1, is the primary m/z selector after the sample leaves the ionization source.
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).
Schematic diagram of the combined ECD FTICRMS and IRMPD experimental setup. Electron-capture dissociation (ECD) is a method of fragmenting gas-phase ions for structure elucidation of peptides and proteins in tandem mass spectrometry. It is one of the most widely used techniques for activation and dissociation of mass selected precursor ion in ...
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 ...
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.