Reduction of radioactivity in oils prior to PCB analysis: A new use for solid phase extraction cartridges

摘要

Radioactively contaminated oils represent a significant waste problem throughout the Department of Energy complex (DOE). From contaminated oils in glove box facilities at Los Alamos National Laboratory (LANL) through the 1200 kg of oil waste at Paducah to an estimated 46,000 kg of contaminated oily water at Lawrence Livermore, contaminated oil exists at all of the DOE facilities. Dilution is the primary mechanism for reducing the radionuclides to safe handling levels prior to analysis. However, this approach requires contamination of instrumentation as well as increased limits of quantitation. Often, the dilutions required to maintain As Low As Reasonably Achievable (ALARA) guidelines result in limits of quantitation which are above the regulatory limits for waste acceptance. In order to maintain ALARA guidelines while obtaining the lowest possible detection limits, the Organic Analysis Group at Los Alamos National Laboratory has established a cleanup technique for oils suspected of being contaminated with polychlorinated biphenyls. The technique uses a 0.02 microm disposable filter in conjunction with Florisil SPE cartridges. Using this technique we have demonstrated radionuclide reductions ranging from 60 to 95+% for gross alpha, beta, and gamma while maintaining analyte and surrogate recoveries well within established guidelines. Further advantages of this technique include its simplicity, the generation of a minimum of secondary waste materials, and the potential for field use. Implications of this analytical technique as well as applications to other analytes of interest are currently being explored.