Appropriate use of EPA Methods 8082 and 1668

EPA Method 8082 can be used to determine concentrations of PCBs as Aroclors or as individual PCB congeners in extracts from solid, tissue, and aqueous matrices. Method 8082 provides procedures for 19 of the 209 possible PCB congeners (see Table 1). The 19 PCB congeners are specific to the common Aroclor formulations (USEPA, 2007b).

However, as reflected in the PSEP, Method 8082 is not appropriate for the determination of co­ planar PCB congeners or the other PCBs of greatest toxicological significance measured at the very low (sub part per trillion) concentrations (USEPA, 2007b).

EPA Method 1668 can be used to determine concentrations of chlorinated biphenyl (CB) congeners for wastewater, surface water, soil, sediment, biosolids, and tissue matrices. The CB congeners that can be determined by this method are the twelve (12) polychlorinated biphenyls (PCBs) designated as toxic by the World Health Organization (WHO): congeners 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, and 189. Method 1668 also determines the remaining 197 CB congeners. Of these, approximately 125 are resolved adequately on an SPB-octyl gas chromatographic column to be determined as individual congeners. The remaining (approximately 70) CB congeners are determined as mixtures of isomers (co-elution’s) (USEPA, 2010).

Method 1668 is appropriate for determining the concentrations of all 209 PCB congeners, including those co-planar PCB congeners or the other PCBs of greatest toxicological significance measured at the very low (sub part per trillion) concentrations, which are sometimes needed for specific risk assessment procedures.

The standard analytical method for PCB mixtures-BPA Method 8082-may be appropriate at contaminated sites when testing is only needed for total PCBs based on Aroclors.

However, given its limitations, EPA Method 8082 is not appropriate when:

There is a need to test for PCB congeners that EPA Method 8082 does not test for (i.e., congeners other than Aroclors or the 19 listed PCB congeners).

There is a need to detect concentrations below what EPA Method 8082 is able to detect (i.e., ppt vs. ppm or ppb), such as when evaluating compliance with the current surface water cleanup level of 0.000064 ug/L.