VOC Diffusion Tubes / Passive Samplers

Volatile Organic Compounds (VOCs) Diffusion Tubes

Volatile Organic Compounds (VOCs) Diffusion Tubes / Passive Samplers

Volatile organic compounds (VOCs) in the range C2-C28 can be measured using a variety of sorbents to meet the specific applications required by the customer. Polyaromatic hydrocarbons (PAHs) can also be measured using a specific sorbent.

VOC emissions into ambient air originate from a variety of sources. These hazardous gases can present health problems and are therefore widely monitored for compliance with air quality guidelines.

Outdoor sources of VOC pollution:

  • Vehicles.
  • Industrial processes (including stack emissions).
  • Fossil fuels.
  • Pesticides.
  • Tobacco smoke.

Indoor sources of VOC pollution:

  • Building materials
  • Paints and permanent markers
  • Adhesives
  • Cleaning products and air fresheners, including dry-cleaned clothing.
  • Refrigerants.
  • Furnishings.
  • Photocopiers.
  • Solvents.
  • Fuels.
  • Tobacco smoke.

VOCs can be measured from low parts per billion (ppb) to parts per million (ppm) levels using these thermal desorption sorbent tubes. Sampling times start from 1 hour for pumped sampling up to 4 weeks for passive sampling. Need shorter monitoring periods by passive sampling? Try our New Rapid Air Monitor.

VOCs in soil can also be monitored with these tubes in conjunction with soil probes. Soil contamination can occur in proximity to oil refineries, chemical plants, landfill, petrol stations and industrial sites.

Potential implications of VOC pollution:

  • Eye, nose and throat irritation.
  • Nausea and headaches.
  • Fatigue.
  • Dizziness.
  • Allergic skin reaction.
  • Involved in ground-level Ozone formation.


This tube can be packed with a range of sorbents to meet monitoring needs. Gradko can supply different tubes which will cover compounds in the range C2-C28.

The tubes for passive monitoring typically contain one type of sorbent, to cover a specific range of compounds. For pumped sampling tubes can contain one, two or three sorbent types, allowing a broader range of compounds to be monitored.

Commonly requested applications for volatile organic compound measuring include:

  • BTEX analysis from vehicle emissions
  • Benzene monitoring
  • Total petroleum hydrocarbon analysis
  • Landfill gas emissions detection
  • Pesticide monitoring
  • PAH detection
  • Anaesthetic gas monitoring for occupational exposure assessments (please see anaesthetics product page).


Tube hire – please contact our Technical Advice department to discuss the most appropriate sorbent to use.

Gas sampling bags – an alternative to sorbent tubes.

Analysis options – A wide range of analysis options are available to suit each individual customers requirements, including:

  • Top 5 or 5 named compounds
  • Top 10 or 10 named compounds
  • Top 15 or 15 named compounds
  • Top 20 or 20 named compounds
  • Full scan analysis – reporting of all compounds found on the tube (down to 10ng concentration)
  • Reporting of Total VOCs
  • Semi-quantitative or quantitative analysis
  • Gas sampling bag analysis

Analysis is carried out in our UKAS accredited laboratories. Results are provided within 10 working days or can be fast-tracked by arrangement.

Ormantine USA, Ltd. | Environmental Monitoring Division | Peristaltic Pump Tubing Division