What is the purpose of multiple reaction monitoring (MRM) in LC-MS/MS?

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Multiple Choice

What is the purpose of multiple reaction monitoring (MRM) in LC-MS/MS?

MRM in LC-MS/MS focuses on tracking defined precursor-to-product ion transitions for each target compound. In a tandem mass spectrometer, the first quadrupole isolates a specific precursor ion from the analyte, the collision cell fragments it, and the third quadrupole selects a particular product ion. By monitoring only these chosen transitions, the method becomes highly selective for the analyte amid complex mixtures, which reduces interference and supports precise quantification. This setup also allows multiplexing, so multiple transitions for different analytes can be measured in a single run, boosting sensitivity and throughput. Internal standards are often used to improve accuracy by correcting for variability in ionization and instrument response. The other choices describe functions not related to MRM: calibrating temperature, single ion detection (which is SIM, not MRM), and identifying structure via NMR.

MRM in LC-MS/MS focuses on tracking defined precursor-to-product ion transitions for each target compound. In a tandem mass spectrometer, the first quadrupole isolates a specific precursor ion from the analyte, the collision cell fragments it, and the third quadrupole selects a particular product ion. By monitoring only these chosen transitions, the method becomes highly selective for the analyte amid complex mixtures, which reduces interference and supports precise quantification. This setup also allows multiplexing, so multiple transitions for different analytes can be measured in a single run, boosting sensitivity and throughput. Internal standards are often used to improve accuracy by correcting for variability in ionization and instrument response. The other choices describe functions not related to MRM: calibrating temperature, single ion detection (which is SIM, not MRM), and identifying structure via NMR.

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