Everything You Need to Know About Gas Chromatography Analyzers

Gas Chromatography (GC) largely affects the world around it, yet few know just how important it is or even how it works. GC is a technique which separates a gas mixture to determine the presence and concentration of gases and impurities in a sample. When applied correctly, this method can measure down to ppb levels. This makes GC extremely well suited for use in high purity processes. The natural gas industry uses this method each day in their work, and you use gasoline or another type of fuel every single day to go about your daily life, which means you are unknowingly using GC everyday of your life. Wow!

Now that you know you directly benefit from GC as a science, the question becomes- what really is it? How is it done? In GC, gas mixture components are separated by circulating a gas sample, using an inert carrier gas, into a flow-through circular tube. This is known as a column. The different gas constituents are separated due to their interaction with the column material. This causes each different molecules in the sample to elute at different times, providing unique retention time. Each individual molecular properties of each gas cause it to travel through and exit at a different time. These retention times are then detected by a sensor at the column exit. Does it sound complicated? It is nothing state-of-the-art GC data analysis software can’t handle! 

The GC process isn’t over quite yet. The comparison of retention times allows those working with it to qualitatively identify gas types by the order in which they elute from the column. If conditions are constant, a particular gas will elute with the same retention time, which thereby allows a specific gas type or types to be deduced from the area of the peak. At the same time, the relative volume of each gas concentration can also be measured by the Gas Chromatography analyzers as each gas elutes from the column. 

The conditions by which GC operates for a given application are invariably different and require individual optimization. Because of this, the majority of these special analyzers are preset at the factory. They arrive at the field with application specific valve timings, flow and temperature settings, and peak detection parameters. This is what is best for everyone, as it makes the process more efficient and easier to know if it is correct. 

If you’re looking to purchase a GC analyzer for your company, you’ll want to ensure you get one that is comprehensive in nature. Be sure to go with a software company that is one of the best in the industry, meaning they have their own patented or trademarked hardware and software technologies, chromatography columns, consumables, reference and calibration standards, installation, training and responsive ongoing support.

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