6.12:
Gas Chromatography–Mass Spectrometry (GC–MS)
Gas chromatography–mass spectrometry, or GC–MS, combines gas chromatography and mass spectrometry in a single instrument for analyzing a mixture of compounds.
The gas chromatograph is used to separate the compounds, and the mass spectrometer is used to analyze the mass of each compound.
The chromatograph setup consists of a long, narrow capillary column housed in an oven. The stationary phase is a high-boiling-point silicone-based material with low polarity and high viscosity coated on the inner surface of the column.
The analyte is injected at the chromatograph's column inlet, where an inert carrier gas—the mobile phase—carries it across to the mass spectrometer.
The compounds in the analyte travel through the column at different speeds because of the difference in their boiling point and affinity toward the stationary phase.
So, the compounds reach the other end of the column at different time intervals, where an attached mass spectrometer analyzes the mass signals from each compound separately.
6.12:
Gas Chromatography–Mass Spectrometry (GC–MS)
Gas chromatography–mass spectrometry (GC–MS) is the combination of analytical techniques of gas chromatography and mass spectrometry in a single instrument for analyzing a mixture of compounds. The gas chromatograph separates the compounds in the mixture, and the mass spectrometer analyzes each compound separately to determine the molecular masses and molecular structures.
A gas chromatograph consists of a long, narrow capillary column with a polysiloxane coating on the inner wall. The coating material features a high boiling point, low viscosity, and low polarity and functions as the stationary phase of the chromatograph. The analyte is injected into one end of the column and flushed through the column using an inert gas flow as the mobile phase. The boiling point of each compound and its interaction with the stationary phase determines the speed of movement through the column. Consequently, each compound in the mixture reaches the other end of the column at a different time. Eventually, the mass spectrometer connected to the column's end analyzes each compound separately.