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1.9.2.1 Typical application
You typically use the precursor ion spectrum for structural elucidation—to complement or confirm
product scan data—by scanning for all the precursors of a common product ion.
1.9.3 MRM mode
MRM mode is the highly selective MS/MS equivalent of SIR. Because both MS1 and MS2 are
static, greater dwell time on the ions of interest is possible, so compared with scanning-mode
MS/MS, the sensitivity achieved is better. This mode is the most commonly used acquisition
mode for quantitative analysis and allows the compound of interest to be isolated from the
chemical background noise.
Figure 1–21: MRM mode
MS1–Static (at precursor mass)
Collision cell–Fragment precursor ions and pass all masses
MS2–Static (at product mass)
1.9.3.1 Typical application
You typically use MRM mode to quantify known analytes in complex samples:
• food and environmental studies; for example, pesticide and herbicide analysis
• forensic or toxicology studies; for example, screening for target drugs in sports testing
• drug metabolite and pharmacokinetic studies
MRM mode does not produce a spectrum, because only one transition is monitored at a time. As
in SIR mode, a chromatogram is produced.
1.9.4 PICS mode
A variation on MRM that is activated by a single check box, PICS allows you to collect a product
ion spectrum or MS Scan spectrum from the top of all detected peaks in MRM mode, for
additional confidence in your peak assignment.
April 27, 2020, 715005564 Ver. 01 (previously released as Rev. A)
Page 33
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