PANGAEA GEOCHEMICAL TECHNOLOGIES

Active Adsorbent Gas-Sieve Analysis

Sample Concentration and Collection 

   The gas-sieve is filled with various packing materials that act as filters/adsorbents to collect and concentrate the C1-C18 hydrocarbon components of a soil vapor sample.  The hydrocarbons are retained on the gas-sieve for extended periods allowing for sample integrity.  The gas-sieve is small, light and easily shipped.  One gas-sieve is used at each sample location.  1000 milliliters of soil vapor is drawn across a gas-sieve at the rate of 250 ml/minute.  This is termed "active" vapor sampling.

     Strict lab QA/QC is followed and special techniques are used to ensure proper GC/FID/FID and GC/MS identification of analytes.  Duplicate and field blanks establish method integrity.   

    Hydrocarbon concentration and composition data is reported.  Fingerprints of known fields (if available) are used to establish models against which sample fingerprints are compared.  Hydrocarbon flux rates are determined and used in the interpretation.