Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects.

In an environmental analysis context, the VOC designation, or volatile organic contaminants, generally refers to the analysis of compounds in environmental samples with the following chemical properties:

• Low boiling points (below 200°C)
• Low vapor pressures
• Low-to-medium water solubility
• Organic compounds
• Low molecular weights
• Henry’s Law Constant (H)*10-3–10-5 atm*m3/mol’

At PPB Analytical, we utilize one of the most sensitive and common methods of VOC analysis with purge and trap concentration.

• Sample is deposited into the sparging vessel where method analytes are purged from the water using a helium or other inert gas stream to sparge through the sample. As with static headspace heat is sometimes applied to drive VOCs out of liquid phase and into the gas phase.
• Once liberated from the sample VOC’s in the gas phase are transferred to an adsorbent trap where they will transiently bind.
• The trap is then heated and backflushed with carrier gas to drive the analytes into a gas chromatographic.