A sample containing a mixture of volatile organic compounds is analysed using gas-liquid chromatography (GLC). Which statement regarding this analysis is correct?
The inert carrier gas acts as the mobile phase and its solubility in the liquid stationary phase determines the separation of the sample components.
When a polar liquid stationary phase is used, non-polar compounds will have shorter retention times than polar compounds of similar boiling point.
The concentration of each component in the sample is determined by measuring its retention time on the gas chromatogram.
In a coupled GC-MS system, the mass spectrometer identifies each component by comparing its infrared absorption spectrum to a database of known standards.