Generally, Polychlorinated Biphenyls (PCBs) are regulated and reported as either a total value or as a number of individual Aroclors. However there may be jurisdictions or other guidelines indicating alternative reporting requirements.
The simplest approach for analysis is Total PCBs + Aroclors by Gas Chromatography with Electron Capture Detector. GC/ECD).
Identification is achieved by comparing the pattern (chromatogram) of the sample to that of know Aroclor standards (1060, 1242, 1254 and 1260 being the most common).
Alternatively analysis can target specific PCB Congeners - homologue groups. The data is reported as Total PCBs in the various homologue group: Di, Tri, Tetra,...Octa (where each group represents the number of substitued chlorines).
This approach allows for more specificity on the concentration on a particular type of PCB, rather than a broader "total" as with measuring Aroclors.
If more specificity is required, PCBs can be analysed via High Resolution Mass Spectrometry (HR/MS) where the individual PCB congeners are reported. This approach has wide applications in impact identification, profiling and forensic investigation of PCBs. Up to 175 individual PCB congeners are typically reported.
Each approach will yield accurate PCB results and requires various levels of effort to complete and thus have different costs associated with analysis. (see our Fee Schedule for associated costs of each approach).
It is important to match the approach with your data objectives.