Name two sorbent media commonly used in active air sampling for VOCs.

• A. Activated charcoal alone
• B. Tenax TA alone
• C. Silica gel and molecular sieve
• D. Activated charcoal and Tenax TA

Answer: (D)

In active air sampling for VOCs, you want a sorbent setup that covers a wide range of compounds. Activated charcoal has a large surface area and strong adsorption for many VOCs, including heavier molecules, making it a versatile main catcher. Tenax TA is a porous polymer that traps a broad spectrum of VOCs well, with clean desorption and good stability, especially for lighter, more volatile compounds. Using both media in series on a single sampling device broadens the overall capture range and improves recovery, since what charcoal holds well and what Tenax TA holds well complement each other. That combination is a common, practical choice for VOC active sampling.