Standard Operating Procedures for Sample Collection Using Tedlar Bags and Adsorbent TubesApril 29, 2023
Introduction Tedlar Bags and Adsorbent Tubes
This Standard Operating Procedure (SOP) aims to provide guidelines for the proper collection, handling, and storage of air samples using Tedlar bags and adsorbent tubes. Tedlar bags are polyvinyl fluoride (PVF) for collecting and storing gaseous samples. At the same time, adsorbent tubes are glass or stainless-steel tubes filled with an adsorbent material for containing volatile organic compounds (VOCs) from air samples. This SOP aims to ensure that the collected samples are accurate and representative, preventing contamination or loss of analytes during sampling.
Materials and Equipment
- Tedlar bags (appropriate size for the sampling volume)
- Adsorbent tubes (with suitable adsorbent material)
- Sampling pump (calibrated)
- Tubing (PTFE or other chemically inert materials)
- Connectors and fittings
- Personal protective equipment (PPE): gloves, safety glasses, and lab coat
- Inspect the Tedlar bags and adsorbent tubes for defects or damage. Ensure that the bags are clean and free of any contaminants.
- Calibrate the sampling pump according to the manufacturer’s instructions and set the desired flow rate.
- Assemble the sampling train by connecting the pump, tubing, Tedlar bag, and adsorbent tube using appropriate connectors and fittings.
- Put on the required PPE before beginning the sample collection.
- Purge the Tedlar bag by inflating and deflating it three times using clean, ambient air.
- Connect the sampling train to the air sampling point or source.
- Turn on the sampling pump and collect the sample at the desired flow rate. Monitor the pump and flow rate during the sampling process.
- Once the required sample volume has been collected, close the Tedlar bag valve and disconnect the sampling train from the air sampling point.
- Seal the adsorbent tube using the appropriate end caps or plugs. Label the Tedlar bag and adsorbent tube with relevant information, such as sample ID, date, time, and location.
Sample Storage and Transportation
- Store the Tedlar bags in a cool, dark place; avoid keeping them in direct sunlight or heat sources, and maintain them at a stable temperature (e.g., 4°C).
- Store the adsorbent tubes in a sealed container or plastic bag to prevent contamination or exposure to moisture.
- Transport the samples to the laboratory as soon as possible, following any specific guidelines provided by the analytical laboratory.
Safety and Precautions
- Always wear appropriate PPE during the sampling process.
- Follow the manufacturer’s instructions for the equipment and materials used.
- Be aware of potential hazards associated with the sampling location or the collected analytes.
- Properly dispose of used materials and equipment according to local regulations and guidelines.
Quality Assurance and Quality Control
- Regularly calibrate and maintain the sampling equipment to ensure accurate and consistent measurements.
- Follow the analytical laboratory’s sample collection, handling, and storage guidelines.
- Include field blanks, duplicates, and other quality control samples as required by the specific project or laboratory guidelines.