Pyrolysis-GC/FID test for biogenic interference in contaminated soil

"Biogenic interference" is that portion of natural organic matter in soil t hat cannot be distinguished From petroleum in a standard rest for contamina tion. Biogenic interference is normally a small fraction of total natural o rganic matter. In organic soils, however, biogenic interference alone can e xceed "petroleum" limits set by regulatory agencies. A test using a pyrolys is-gas chromatograph/flame ionization detector (GC/FID) was developed to qu antify biogenic interference in soil samples from northern Alaska. The samp les had no known history of contamination, so all measured "petroleum" was derived from biogenic interference. The pyrolysis test was found to predict biogenic interference in soil samples more accurately than any combination of standard soil tests, including C:N ratio, pH, percent organic carbon, e xtractable carbon, humic acids, fulvic acids, low molecular weight acids, h ydrophobic neutrals, and hydrophilic neutrals. Analysis of samples contamin ated in the laboratory confirmed that the pyrolysis test could quantify bio genic interference in soils recently contaminated by petroleum.