Evaluation of a thermal desorption gas chromatograph/mass spectrometer: on-site detection of polychlorinated biphenyls at a hazardous waste site

Abstract

A thermal desorption gas chromatograph/mass spectrometer (MGC/MS) has been evaluated for on-site detection of polychlorinated biphenyls (PCB) in soil/sediment. The MS was operated in the selected ion monitoring mode for the simultaneous detection of PCB congeners 1-8, octachlorinated naphthalene, and deuterated polycyclic aromatic hydrocarbon standards. The linearity of the detector was established over 3 orders of magnitude of compound thermally desorbed. Methods were developed which provided screening level (semiquantitative) analyses in 2-5 min/sample and more quantitative analyses in less than 20 min/sample (including sample preparation time). Method detection limits were established at sub ppm levels. A commercially purchased PCB standard soil was evaluated to determine method performance in the field. Approximately 35 ppm PCB was found in the soil by thermal desorption from a hexane extraction; soil certified to be 35 ppm PCB, Aroclor 1242. The TDGC/MS was transported to a U.S. Environmental Protection Agency (EPA) hazardous waste (Superfund) site and operated by battery. Several samples were collected and compared between laboratory GC/MS and field TDGC/MS measurements. Findings indicate that the field methods provide data quality comparable to methods mandated by the EPA for the analysis of soils as prescribed by Superfund. 7 refs., 4 figs., 10 tabs.