Selected ion monitoring (SIM) is a
mass spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a '' mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is u ...
scanning mode in which only a limited
mass-to-charge ratio
The mass-to-charge ratio (''m''/''Q'') is a physical quantity relating the ''mass'' (quantity of matter) and the ''electric charge'' of a given particle, expressed in units of kilograms per coulomb (kg/C). It is most widely used in the electro ...
range is transmitted/detected by the instrument, as opposed to the full
spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of color ...
range.
This mode of operation typically results in significantly increased sensitivity. Due to their inherent nature, this technique is most effective—and therefore most common—on
quadrupole mass spectrometers and
Fourier transform ion cyclotron resonance mass spectrometers.
See also
*
Selected reaction monitoring
Selected reaction monitoring (SRM), also called Multiple reaction monitoring, (MRM), is a method used in tandem mass spectrometry in which an ion of a particular mass is selected in the first stage of a tandem mass spectrometer and an ion product ...
References
{{Reflist
Mass spectrometry