Use for dissolved methane, ethane, ethylene and other volatile organic compounds.
Samples are collected using regular vials without preservation. Be sure there is no headspace in vials
Generating headspace by EPA 3810. Using ultra pure Helium or Argon to replace part of water in order to generate the necessary volume of headspace. Heating to a certain temperature and let equilibrium reached for both phase. Take sample from headspace and injected on to GC/FID, GC/TCD and/or GC/MS for different target compounds.
Sampling vials, 40mL 120mL etc.
Detection limits – 1.0 ppmv or ug/L
Headspace method is only available method for dissolved methane, ethane ethylene, carbon dioxide and other very volatile compounds. Samples generated from headspace can be directly injected into GC without any trapping or other processes. It can solve analysis problem for some poor adsorption compounds.
It is not very good for some polar volatile compounds.
EPA 8240, 8260 may be an alternative for some volatile compounds but can not for methane, ethane, ethylene and carbon dioxide.
Natural attenuation, Bio-remediation, etc.