NAA is a very sensitive method for determining the concentration of a multiplicity of elements in oil samples. When the elements are bombarded with neutrons they produce a unique set of isotopic reaction products which may be used as analytical indicators with respect to the progenitor elements. Because trace element patterns (TEP), the species and concentrations of trace elements, are unique among different crude oils, the identification of the source of an oil spill becomes a matter of comparing the TEP of the sample from an oil spill becomes a matter of comparing the TEP of the sample from a oil slick with the TEPs of samples from all possible sources of spills. In this procedure, the sample is irradiated from 1 min and then counted for 1 min with a 3x3-in Nal(T1) detector coupled to a 400 channel pulse ht analyzer. The sample is than irradiated for 30 min and counted at 1 hr and 1 d after the irradiation with a 36 cu cm Ge(Li) detector coupled to a 4096 channel pulse ht analyzer. Many elements were detected by this method and an experimental comparator standard library was developed which relates measured gamma-ray intensities to signal strength for samples of a given size. A practical test of the method was conducted by analyzing 10 blind sets of samples, 4 to a set, including 1 matched pair of samples/set. The method correctly identified the matched pair in each set, and did not identify any unmatched pairs as matched.

  • Corporate Authors:

    Pergamon Press, Incorporated

    Maxwell House, Fairview Park
    Elmsford, NY  United States  10523
  • Authors:
    • Lukens, H R
  • Publication Date: 1975-3

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00157614
  • Record Type: Publication
  • Source Agency: Pollution Abstracts
  • Files: TRIS
  • Created Date: Sep 20 1977 12:00AM