Orbitrap LC-MS Comparison Chart
Choose the Orbitrap MS that's right for your laboratory
|Attributes||Exactive Plus (EMR)||Q Exactive Focus||Q Exactive (Plus)||Q Exactive
|Orbitrap Fusion||Orbitrap Fusion Lumos|
|Max resolution (FWHM) @m/z 200||140k||70k||140k (280k Enh R)||240k||340k||500k||1,000k|
|Mass accuracy, (internal)||<1ppm
|Polarity switch||<1s||Not during run||< 1.1s|
|Multiplex (precursor/ scan)||-||-||10||
|Decision-tree (CID/HCD/ ETD)||-||-||-||-||-||Yes|
Definition of terms
Resolution: Frequently reported in full width at half maximum (FWHM), resolution is the separation of two mass spectrometry peaks and is calculated as the mass of a peak (M) divided by resolving power (∆M).
Mass accuracy: Expressed in parts per million, this value indicates how much an instrument deviates from a known standard or calibrant.
Scan rate: Measured in hertz, the scan rate of an MS indicates how quickly it scans a mass spectrum.
Polarity switch: The collection of both positive and negative sample ionization data (spectra) by the ion trap during a single MS analysis. Polarity switching is applied to the study of drugs, drug metabolites, pesticides, etc.
PRM: Parallel reaction monitoring (PRM) is a targeted method of high resolution MS quantification in which a full scan of each precursor ion transition is monitored; i.e., all fragments derived from the precursor ion are monitored. In contrast, single reaction monitoring (SRM) performs one transition monitoring at a time.
Multiplex: The ability of a mass analyzer to acquire data from multiple precursor ions in the same scan without compromising high signal-to-noise ratio.
MSn: Also termed tandem MS, the use of multiple stage MS to capture product ion spectra of a defined m/z, where n is the number of recorded product ion stages.
ETD: Electron transfer dissociation (ETD) results in the fragmentation of the peptide backbone of MS samples, simplifying identification of peptide modification sites.
Synchronous MS3: A method of quantitation that involves simultaneous selection of several MS2 precursors for MS3 analysis and is often used during TMT and iTRAQ experiments.