From groundwater sampling to food product analysis, gas chromatography (GC) is an effective method of testing for chemical compounds within a sample. Like other chromatography methods, GC allows researchers to separate and identify the molecular components that make up a larger sample. By harnessing the scientific capabilities of gas, this approach has numerous advantages over other sample analysis techniques, especially when testing soil and groundwater. Below are answers to several common questions about it.

What You Should Know About Gas Chromatography 

What does the process involve?

The analysis is performed using a complex device known as a gas chromatograph. First, a technician inserts a liquid sample into a chamber. Regulated pressure pushes the solution through a column, where it is heated and vaporized. Another column of inert gas—such as hydrogen or helium—combines with the sample compounds. The inert gas picks up vaporized molecules to transport them through the chromatograph’s detector. As the substance flows through, the detector identifies present compounds and their respective measurements.

How does it compare to thin-layer chromatography?

Thin-layer chromatography (TLC) is another technique for analyzing samples. During TLC, a technician places a sample on a plate that’s been treated with an adsorbent material—such as silica. The plate is placed in a beaker containing solvent.

The solvent travels through the plate via capillary action and reacts with the sample to identify the compounds it contains. Generally, TLC is best for detecting non-volatile compounds, while GC is better for volatile compound detection. While TLC requires fewer materials, GC delivers results that are more detailed and complex.

What are the advantages?

Compared to all chromatography techniques, GC identifies complex compounds and their quantities with greater sensitivity and accuracy. The testing parameters for these results can be manipulated in real-time, allowing a technician to refine the analysis to meet the project's needs. It is useful in construction because you can identify potential volatile chemicals in groundwater and soil before building on the land. Additionally, the results are available within minutes of testing.

What are some common applications?

Due to its ability to deliver detailed results, GC serves many environmental science and land development applications. For example, it can be used in soil or groundwater sampling to identify pollutants. The petroleum industry, on the other hand, may use GC to test potential oil drilling sites. Many industries also use GC to test products—such as medications or food—for chemical purity.

If you're interested in gas chromatography to assist with your development plans, contact GeoTek Alaska in Anchorage. Whether you need real-time groundwater sampling or comprehensive drilling site analysis, these experts will deliver precise results. They are also equipped to assist with utility locating, auger drilling, and well monitoring. Visit them online for more information about their services. Call (907) 569-5900 to speak with a team member.