TSMS-ANL-003
Liquid Chromatography–Mass Spectrometry (LC-MS) Study Guide
School of Analytical Chemistry · Analytical Chemistry Foundations · Intermediate–Advanced
Open full lessonLearning objectives
- Explain how LC and MS are coupled.
- Describe electrospray ionization.
- Interpret mass-to-charge ratio conceptually.
- Explain peptide charge states and deconvolution.
- Distinguish TIC, EIC, and mass spectra.
- Describe how MS/MS supports sequence-related evidence.
Executive summary
LC-MS combines liquid chromatography with mass spectrometry.
The chromatograph separates components in time. As each compound elutes, the mass spectrometer converts it into ions and measures mass-to-charge ratio.
This combination supports:
- intact-mass confirmation,
- identity assessment,
- impurity characterization,
- degradation-product investigation,
- sequence-related fragmentation analysis,
- quantitative methods.
The chromatograph separates components in time. As each compound elutes, the mass spectrometer converts it into ions and measures mass-to-charge ratio.
This combination supports:
- intact-mass confirmation,
- identity assessment,
- impurity characterization,
- degradation-product investigation,
- sequence-related fragmentation analysis,
- quantitative methods.
Key takeaways
- LC-MS combines separation with mass analysis.
- Electrospray ionization is well suited to peptides.
- Peptides commonly produce multiple charge states.
- Deconvolution reconstructs neutral mass.
- MS/MS supports structural characterization.
- Interpretation requires calibration, controls, and scientific context.
Self-review questions
- What does m/z represent?
- Why do peptides produce several charge states?
- What is the purpose of deconvolution?
- How does an EIC differ from a TIC?
- What additional information does MS/MS provide?
Use the full lesson to verify your answers.