How to speed up your gas chromatography
12/12/17
Comments!
2
4 ways to speed up
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| Implementing techniques to speed up GC is an effective way to streamline your workflow. Research has |
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Use a shorter column |
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| By reducing the length of your capillary column, you can shorten analysis times considerably, even when running the carrier gas at the same linear velocity. Oven programs will be faster, meaning the maximum temperature is reached more quickly. Separation can be slightly affected, so be careful of co-elution. | |
Use a faster carrier gas |
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| Hydrogen is half as viscous as helium, making it about twice as fast at the same temperature and pressure meaning significantly faster separations. The great thing about hydrogen is that you can safely make it in the laboratory using a hydrogen generator, offering a cheap gas solution. Hydrogen has better efficiency than helium at higher linear velocities so your sample will separate well, even at high flow rates. | |
Use a smaller diameter capillary |
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| Working on a very similar principle as a shorter column, replacing a 30 m × 0.25-mm capillary with a 20 m × 0.15- mm capillary can reduce run times by a factor of 2, this should provide the same efficiency when using the same carrier gas. | |
A different temperature program |
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| With a faster oven program rate, you will see quicker elution with a far more compact show of peaks in your results. Though the elution temperature of components may result in different peak separations during this process, increasing the analysis temperature for an isothermal analysis will decrease analysis time. This may result in some loss of resolution, but only if the temperature is increased too fast for your analysis. | |
Comments
I would like to ask your advice that I’v changed the carrier gas to Nitrogen generator in my RGA Gas chromatography SCION 456 , would it give me the same resolution and efficiency as helium,? please be informed that the company preconfigured our GC carrier gas as Helium . Your reply is highly appreciated.
If you are loooking to change from helium to nitrogen carrier gas, you can use this tool from Restek: http://www.restek.com/ezgc-mtfc to check the instrument parameters you need to optimise your efficiency. This work (also by Restek) shows how you can change the column dimensions to https://blog.restek.com/?p=13831 get like-for-like results. You may need to optimise your split flow, but the info there should help you get similar results to your helium method.
Please let us know how you get on, and if you need a generator, you know where to come!
Best regards,
Ed