For samples containing VOCs, what packaging condition is important to preserve the compounds?

• A. Temperature control
• B. Nitrogen flushing
• C. Light exposure
• D. Zero headspace

Answer: (D)

VOCs are highly volatile, so preserving them means preventing their escape from the sample. Having zero headspace means there is no air gap for the vapors to migrate into, drastically reducing loss by evaporation and keeping the concentration in the sample more stable during storage and transport. While temperature control, inert gas flushing, or protecting from light can help in some ways, they don’t prevent volatilization as effectively as eliminating the headspace. Therefore, eliminating headspace best preserves VOCs.