These are sealed glass tubes, with generally 2 sections of adsorbent material. They are used for monitoring levels of organic vapours and gases. Both ends of the tube are broken off and air is drawn through the sampling tube and the vapour or gas that’s being monitored is adsorbed onto the material in the tube. After sampling, the ends of the tube are capped and sent to a laboratory where the material is desorbed from the tube, either chemically or thermally, and analysed usually by a gas chromatograph.
Please see the Introduction to Air Sampling pages for more detail on how to set up the sample train.
Different types of adsorbent material are used; the most common being charcoal and silica gel. Please refer to your MDHS, NIOSH, OSHA or other standard method to find out which type of tube your need. Or use the Hazard Search function on the home page.
Charcoal
This is the standard sorbent tube generally used for organic vapours. They are suitable for most aromatic hydrocarbons and alcohols but please check your standardised method. See more
Silica Gel
This is another commonly used sorbent tube and is suitable for polar hydrocarbons, methanol, amines, inorganic acids and low molecular weight mercaptans (thiols). Some of the tubes in the range are pre-treated (e.g. with 2,4-dinitrophenylhydrazine) for sampling of specific chemical hazards. See more
