• Function of the Mass Spectrometer in GC-MS:
• Analytical Role:
• In Gas Chromatography-Mass Spectrometry (GC-MS), the gas chromatograph separates volatile components in time.
• The mass spectrometer detector ionizes molecules into charged fragments and separates them based on their mass-to-charge ratio ($m/z$), generating characteristic fragmentation spectra for compound identification.
• Conclusion: To separate compounds based on their mass-to-charge ratio (Option 1).

Correct option: (1) To separate compounds based on their mass-to-charge ratio