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5 EXTRACTION METHODS

5.5 HEADSPACE


Use: Headspace extraction methods are an extremely simple technique used to collect VOCs.

Description:

Gas headspace extraction involves the use of dead space to collect gases that are moving through water or soil, or from a solid or liquid phase to a gaseous phase. This can involve placement of water or soil in a container that is partly filled with air (headspace), and collecting a sample of the headspace gas (usually with a syringe once the vapors in the sample have equilibrated with the headspace). Since not all vapors are likely to degas the first time, multiple headspace extraction is sometimes used.

Analytes:

1. Non-Halogenated VOCs 3. Halogenated VOCs

Media:

Soil: Ground Water: Surface Water: Gas/Air:
MODERATE MODERATE MODERATE Not Applicable
Maximum Depth: Not Applicable.
Production Rate: Sample is available quickly.
Investigation Derived Waste Volume: Medium volume of waste.
Technology Status: Commercially available and routinely used field technology.
Certification/Verification: Technology has not participated in CalEPA certification and/or CSCT verification program.
Relative Cost per Sample: Least expensive.

Limitations:

ASTM Standards:

D 3871 - 84 Test Method for Purgeable Organic Compounds in Water using Headspace Sampling.

EPA Methods:

5021 Volatile Organic Compounds in Soils and Other Solid Matrices Using Equilibrium Headspace Analysis.

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