In GC-MS, which component is responsible for separation?

• A. GC
• B. MS
• C. GC-MS
• D. Chromatography

Answer: (A)

Gas chromatography handles the separation. In GC-MS, the sample is carried through a long column with a stationary phase and heated to help volatilize components. Different compounds interact with the column material and have different travel speeds, so they exit the column at different times, creating separate signals. The mass spectrometer then takes the separated stream, ionizes the compounds, and analyzes their mass-to-charge ratios for identification and quantification. So, while the GC-MS as a whole performs both separation and detection, the part that actually separates the mixture is the GC. The MS does not separate, and “chromatography” is the general method, not a specific component.