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2.8.2 Polynuclear Aromatic Hydrocarbons (PAHs) 



The laboratory extracted ten samples by EPA SW-846 Method 3550A (EPA 1997). 

 Prior to extraction, the samples were spiked with surrogate compounds, and extracted 

 sequentially using methylene chloride: acetone and then methylene chloride. Separate 

 aliquots were weighed, dried in an oven, then reweighed for calculation of the moisture 

 content. The extracted samples were concentrated, treated with activated copper to 

 reduce/remove elemental sulfiir, spiked with internal standards, and then analyzed using a 

 modified version of EPA SW-846 Method 8270 (EPA 1997). Method 8270-PAH-SIM 

 (Revision 0; GC/MS-SIM) is a WHG standard operating procedure and a more rigorous 

 method than the standard method 8270. The sample extract containing the semi- volatile 

 compounds was injected into a gas chromatograph (GC) with a narrow-bore fused-silica 

 capillary column. The temperamre-programmed GC column separated the analytes, which 

 were detected with a mass spectrometer with selected ion monitoring. In this method of 

 analysis, qualitative identifications are confirmed by analyzing standards under the same 

 conditions used for samples and comparing mass spectra and GC retention times. The 

 mass spectra of the target analytes were compared with the electron-impact spectra of 

 authentic standards for identification. Quantification is based on a multi-level initial 

 calibration. Samples were reported on a dry weight basis in units of fig/kg and were not 

 adjusted for surrogate recovery. Surrogate recovery analyses provide information on a 

 laboratory's detection accuracy on a sample by sample basis. Because the recovery 

 percentages were acceptable, the data were not biased. Therefore, adjustment for 

 surrogate recoveries was not necessary. 



2.8.3 Pesticides and Polychlorinated Biphenyls (PCBs) 



The WLIS samples were analyzed for organochlorine pesticides and PCB aroclors 

 using a modified version of SW-846 Method 8080A (Gas Chromatography and Electron 

 Capmre Detection [GC-ECD] 8080A, Rev. 2, Woods Hole Group). Prior to extraction, 

 the samples were spiked with surrogate compounds, and extracted by sonication using 

 methylene chloride: acetone. The extracted samples were concentrated, exchanged into 

 hexane, and treated with activated copper to reduce/remove elemental sulfur. For these 

 sediments, no additional cleanup was deemed necessary. Extracts were analyzed for target 

 pesticides and PCBs by GC-ECD. Qualitative identifications are confirmed by analyzing 

 standards. PCB Aroclor standards (Aroclors 1016, 1221, 1232, 1242, 1248, 1254, 1260) 

 and toxaphene were analyzed. Samples were reported on a dry weight basis in units of 

 /xg/kg and were not adjusted for surrogate recovery. 



Monitoring Cruise at the WLIS Disposal Site, September 1997 and March 1998 



