The Reston Groundwater Dating Laboratory

Low-Level VOCs FAQ

  1. What do you mean by the term "low-level" VOC?
    The term "low-level" refers to concentrations that typically are below the minimum detection level (MDL) for VOCs determined by purge and trap capillary column gas chromatography with mass spectrometry (GC-MS), and can be at concentrations as low as 2 to more than 4 orders of magnitude below the commonly reported GC-MS MDL of 0.01 to 0.2 ug/L.
  2. What VOCs are detected?
    The electron-capture detector detects halogenated VOCs. Approximately 60 halogenated VOCs have been detected in chromatographs of untreated ground water. A list of identified and quantifiable compounds is available here. Table 1
  3. How are low-level VOC samples collected?
    Samples are collected following the same procedure as for CFC samples.