Gas Chromatography–Mass Spectrometry (GC-MS) combines two powerful techniques — gas chromatography (GC) and mass spectrometry (MS) — to give both separation and identification of compounds.
Here’s how MS enhances GC analysis:
1. Better Identification
- GC separates the compounds in a mixture.
- MS then identifies each compound by measuring its mass-to-charge ratio (m/z).
- This helps confirm what each peak represents in the GC output.
2. Higher Sensitivity
- The MS detector is more sensitive than regular GC detectors (like FID or TCD).
- It can detect very small amounts of compounds — even at trace levels.
3. Structural Information
- MS provides fragmentation patterns (mass spectra) that show how molecules break apart.
- These patterns help determine the chemical structure of unknown compounds.
4. Database Matching
- The obtained mass spectra can be compared with reference libraries to automatically identify compounds.
5. Greater Selectivity
- Even if two compounds overlap on the GC chromatogram, MS can distinguish them based on their different mass spectra.
In short:
Mass spectrometry makes gas chromatography more powerful by giving accurate identification, higher sensitivity, and structural details of the separated compounds.