High Purity Gases & Their Applications in Laboratories
Today, modern laboratories are continuously testing, examining and analyzing. Part of what makes that possible is the use of compressed gases like Helium, Hydrogen and Nitrogen. We typically see labs using these gases for different applications whether they are being used to power instruments or as a carrier gas to carry samples for chromatography.
Depending on what the gases are being used for will determine what grade you’ll need. For example, a high purity gas may be required for sampling as there are fewer impurities that could potentially cause inaccurate results. Gas purity can have a big effect on the work that is being done in a laboratory.
In this blog post we’re going to cover some common laboratory applications and how gases are used within those processes.
Atmosphere Control
As we know, running tests and analysis in the laboratory can become dangerous based on many factors. One of those factors is the atmosphere of the environment. Laboratories contain sensitive equipment, samples and procedures that are performed there.
In order to maintain the optimal levels of oxygen, humidity and temperature in the lab, nitrogen gas is commonly used. As a non reactive gas, it’s the perfect element to keep the atmosphere in the labs stable.
In addition to maintaining optimal oxygen levels in the atmosphere in laboratories, it can also help control oxygen levels in other lab equipment like glove boxes and cell incubators.
Chromatography
Helium and hydrogen are commonly used in gas chromatography as the carrier gas of choice. This is due to the fact they are efficient gases with a larger flow rate and they work with the majority of detection systems. The detection system provides the measurements of the mixture with the carrier gas.
Other gases can be used as the carrier gas like argon or nitrogen, but it depends on what detector system is being used as there are different types. Helium typically has a shorter analysis time because it’s a lighter gas and has a high flow rate.
When ordering a gas to use as the carrier, you’ll want to make sure they are ultra high purity gases with very low levels of oxygen in the tank. When the gases are put to use, they are put through a gas system within the laboratory that removes any potential contamination or water.
The pressure at which the gases are released is also important. Pressure surges should be avoided through the use of a pressure regulator on the tank and on the chromatograph gas inlet.
Evaporative Light-Scattering Detectors (ELSD)
There are different types of chromatography methods, but for high pressure liquid chromatography in particular, ELS detectors are used. These ELS detectors can help identify samples that can’t be found using UV detection.
ELSDs require a clean inert gas in order to convert the fluids used to wash the components that are being tested into a spray. This is where nitrogen plays a vital role. The components being tested are carried by nitrogen gas to create the spray, which is then heated to evaporate.
Sometimes compressed air can be used in ELS detectors but this would require an extra step in order to remove any traces of oil or water that may be left behind. This is a reason why it is preferred to use a clean inert gas like nitrogen.
Instrumentation
As a rule of thumb for gases used for laboratory instruments, the higher the purity, the lower levels of impurities can arise which are what cause problems with the instruments and results that come from measurement and analysis.
Various high purity gases are used including: helium, hydrogen, argon and nitrogen. Nitrogen and other gas mixes are used for instrument span calibration as each instrument has a different minimum and maximum calibration span it can support.
Additionally, gases are used to purge analytical equipment, which is why high purity levels are important when applying gases in laboratories.
At Air Source Industries, we provide our customers with a wide range of gas products from a variety of high purity gases to specialized gas mixtures. We have rigorous quality control processes at our facility to make sure that our gases consistently meet your needs. We comply with FDA regulations and follow CGA specifications.
Customer service is our priority, so we are very serious about taking the time to help you figure out exactly what you need to get the job done. We also provide next business day delivery and can install the tanks based on your needs and availability.
If you’re in the market for high purity gases and special mixtures, you’ve come to the right place. Don’t hesitate to call us at (562) 426-4017 if you have any questions at all. You can also fill out our online quote form for a free quote.
Sources:
https://www.digitalrefining.com/article/1000021/gases-and-gas-handling-for-the-lab-environment#.YZbklb3MKS4
https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Supplemental_Modules_(Analytical_Chemistry)/Instrumental_Analysis/Chromatography/Gas_Chromatography
https://www.peakscientific.com/discover/news/what-are-evaporative-light-scattering-detectors/
https://ionscience.com/usa/news/gases-found-within-pharmaceutical-and-bioanalytical-laboratories/