Gas-Liquid Chromatography

Introduction to Gas-Liquid Chromatography

• Gas-Liquid Chromatography (GLC), also known as Gas Chromatography, is a method used to separate volatile substances in a mixture.
• It’s a method essential for analytical chemistry, providing detailed information about the mixture’s components.

Basic Components of Gas-Liquid Chromatography

• The process utilises a gaseous mobile phase (the carrier gas, often hydrogen or helium) and a liquid stationary phase (a high boiling substance coated onto an inert solid).
• The apparatus typically consists of an injection port, a column (where separation happens), and a detector.

Procedure of Gas-Liquid Chromatography

• The mixture is vapourised and carried by the carrier gas into a column.
• Different components in the mixture interact differently with the stationary phase, leading to their separation in the column.
• The retention time, the duration that a compound is in the column, is used to characterize each component.
• The detector then registers the separated compounds as they exit the column, and this is represented on a graph called a chromatogram.

Applications of Gas-Liquid Chromatography

• It’s widely applied in various fields such as forensics, environmental monitoring and pharmaceuticals for the detection and identification of substances.
• It’s also used in quality control to ensure uniformity and consistency in products.

Limitations and Precautions in Gas-Liquid Chromatography

• GLC is only useful for volatile substances; non-volatile substances cannot be analysed using this method.
• Careful interpretation of chromatograms is crucial as compounds with similar retention times might co-elute, leading to inaccurate results.
• One must ensure that the carrier gas does not react with the compounds under analysis.