How Does Nitrogen Evaporation Work?



August 10, 2023

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  • How Does Nitrogen Evaporation Work? Nitrogen evaporation is a common step in sample preparation that is used by many types of laboratories. It’s meant to remove excess solvent from test samples prior to chromatography, mass spectrometry, or other analytical techniques. It is used in a variety of industries, including environmental testing, food & beverage, toxicology, pharmaceutical, and medical. Although nitrogen blowdown evaporation can be performed by hand, laboratories will often use a nitrogen evaporator to make the process more efficient. A lab technician will begin by placing their test samples into a nitrogen evaporator. They will then be lowered into a heated water bath which is set a to a few degrees lower than the boiling point of the solvent you’re working with. Some nitrogen evaporators utilize a dry block instead of a water bath for the heat source. The gas delivery needles are then positioned to be just above the surface of the solvent. The gentle stream of nitrogen should create a dimple on top of the sample. The samples will remain in this position until they are concentrated down to the desired level. So how does this process actually work, and how does it cause faster evaporation rates? Let’s take a look at the physics behind it. By introducing a stream of nitrogen gas being blown on the sample, this decreases the vapor pressure just above the surface of the sample. This prevents any vapor from returning back to the solvent, while allowing more vapor to dissipate. However, the nitrogen gas can also cool the sample slightly, which decreases the energy of the molecules, slowing down their movement and ability to vaporize. By introducing a form of heat to the sample, it causes the molecules to re-energize and speed back up. The sample is now in an optimal environment for concentration. The combination of heat and nitrogen blowdown allows the molecules to quickly vaporize and be whisked away from the sample. The entire process is efficient, yet gentle to prevent any damage to your sensitive samples. On average, it takes just 25 minutes to safely concentrate down a 10 mL sample of methylene chloride using nitrogen blowdown. For more information on blowdown technology and how it can be used, check out our past video titled “What is Nitrogen Blowdown Evaporation”. For any additional questions on the glassware installation, please reach out to our sales team at Contact Us: Music from #Uppbeat (free for Creators!): License code: Z2TJSIFTDOKS3DVG Link to video "What Is Nitrogen Blowdown Evaporation":

    Analytical TechniquesChromatographyEnvironmental ScienceMass Spectrometry

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