MRM
Definition
Multiple Reaction Monitoring. LC-MS-MS or GC-MS-MS mode that follows specific precursor-to-product ion transitions for each target analyte, giving very high selectivity at low concentrations.
- Full name
- Multiple Reaction Monitoring
- Platform
- LC-MS/MS or GC-MS/MS
- Monitors
- Precursor-to-product ion transitions
- Strength
- High selectivity at low analyte concentration
Common questions
Why is MRM preferred over full-scan mass spectrometry for confirmation?+
Full-scan mode records the entire mass range and can be less sensitive per compound, while MRM targets only the specific precursor and product ion pair for each analyte, which improves both sensitivity and specificity, letting toxicologists confirm a target drug at trace concentrations against a busy chemical background.
What limits MRM's usefulness compared to full-scan analysis?+
Because MRM only monitors pre-selected transitions, it will not detect an unexpected or unanticipated compound outside the target list, so laboratories often run a full-scan or high-resolution screen first to decide what to target with MRM confirmation.
How does MRM support courtroom-defensible drug confirmation?+
Matching both the precursor and characteristic product ion transitions, along with retention time, against a certified reference standard gives a confirmation result that meets the two-point identification criteria most forensic toxicology accreditation standards require.
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