Preventing Sample Contamination in an Evaporation System || Organomation



August 2, 2022

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  • Contact Us: Preventing Sample Contamination in an Evaporation System Sample contamination is a risk that virtually all labs have to be mindful of. Common sources of contamination include compounds in the atmosphere or sample residue left behind on improperly cleaned equipment. Many of Organomation’s products use nitrogen blowdown as a common evaporation technique. Here are some tips to prevent sample contamination in any nitrogen evaporator. Make sure that all sample vials are properly cleaned before coming in contact with a sample. They should also be properly stored in a sanitized area between uses. Similarly, make sure that all gas delivery needles are clear of any residues. It’s recommended to clean and examine the needles between each use. Organomation also offers pipet adapters, which allow glass pipets to be used in place of stainless steel needles. Since glass pipets are disposable, they are recommended for applications where contamination is a pressing concern. Use caution when placing sample tubes in the evaporator. Before placing the samples in the unit, raise the needles as high as possible. This will allow tubes to be placed in the holder without tipping. When lowering the needles back into place, avoid contact with the solvent. Ensure that your gas source is clean and dry. If any inert gas is being used, it should be high or ultra-high purity depending on the application. When using atmospheric air from a compressor, a dryer and micro filter may be needed as well.” It’s also important to avoid excessive sample turbulence due to high gas flow. Solvent splashing may result in sample loss, cross contamination, or needle contamination. We recommend setting the gas flow rate at a low setting, and slowly increasing it until a dimple is visible on the sample’s surface. Try to avoid a bath temperature that is too high, which can create condensation on the evaporator. The condensed solvent may drip into the sample or leave residue on the needles. The recommended bath temperature is 2-3°C below the solvent’s boiling point. Once evaporation is complete, use caution when removing the samples from the unit. Raise the needles as high as possible so that they don’t come in contact with the sample. Make sure the gas flow is turned off during this step, to avoid any accidental splashing. Although sample contamination will always be a concern for labs, having strict procedures and properly trained personnel will help reduce the risks. Maintaining these preventative measures will ultimately save the laboratory valuable time and money. If you have any questions or concerns, please reach out to or call 978-838-7300 to speak to one of Organomation’s sales technicians.

    Analytical TechniquesChromatographyEnvironmental ScienceMass Spectrometry

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