US EPA Method 325 – Passive Sampling on ¼” OD Tubes
• Meets requirements of U.S. EPA Method 325 finalized Fall 2015
• 8 hr – 2 week passive sampling provides highly reproducible results for BTEX and similar boiling range VOCs.
• More reproducible than radial samplers because sample is backflushed during thermal desorption rather than pushed through the entire adsorbent bed.
• Carbon Tetrachloride is quantitatively recovered, so Global background of 70 ppt can be used to validate proper sampling when performing GCMS or GC/FID/ECD