This process relies on the interaction of molecules with the mobile and stationary phases within the GC system. Less volatile compounds interact more with the stationary phase, resulting in slower movement, while more volatile ones interact more with the mobile phase, leading to faster movement. When the analyte is detected, the computer generates a peak indicating the retention time of the sample. The area under this peak provides concentration information, collectively forming a chromatogram.

Gas chromatography systems, also known as GC systems or gas chromatographs, leverage these principles to conduct precise compound analyses, and are essential instruments in various industries where the isolation and analysis of volatile compounds is necessary.

There are a number of components used in GC systems, including (we’ll cover these components in further detail below):

• Carrier Gas: The mobile phase in a GC system is a carrier gas, usually an inert gas like helium. Helium is the preferred choice for its nonreactive nature.
• Stationary Phase: This refers to a microscopic layer of polymer or liquid set on an inert support inside tubing, typically made of glass or metal.
• Injector: The injector is responsible for introducing the sample into the system. It must ensure that the sample is vaporized and transported into the column efficiently.
• Column: This is the heart of the system, where separation of compounds takes place. The stationary phase-coated column interacts with the compounds, causing them to elute at different times.
• GC Detector: The detector quantifies the separated compounds. Various types of detectors, like Flame Ionization Detectors (FID) or Mass Spectrometers (MS), can be used based on specific analytical needs.

During gas chromatography, the separation occurs due to the interaction between the molecules and the stationary phase. Less volatile molecules interact more with the stationary phase, leading to slower movement, while more volatile molecules interact more with the mobile phase, resulting in faster movement. When the analyte is detected, the computer generates a peak corresponding to the retention time of the sample. The area under the peak provides information about the sample's concentration, forming a chromatogram.

Several renowned companies specialize in manufacturing high-quality GC systems. Some of the industry leaders include Agilent Technologies, Thermo Fisher Scientific, Shimadzu Corporation, and PerkinElmer, among others.

Gas chromatography systems find extensive applications in diverse fields, including life sciences, pharmaceuticals, and industrial manufacturing. They are crucial for tasks such as compound separation in mixtures and purity testing.

One limitation to be aware of is that GC systems can only analyze compounds up to a certain molecular weight. It's essential to consider this factor when selecting an appropriate system for a specific analysis.