Polychlorinated Biphenyls (PCBs)
Polychlorinated Biphenyls (PCBs) were widely manufactured for use in electric transformers, capacitors, and even for microscope oils. PCBs were banned in 1979, but only after 1.5 billion pounds were manufactured.
There are a total of 209 PCBs, called congeners. There distribution is global based on the formulations for their manufacture and their individual chemical properties. SRIF has developed methods for extracting PCBs from samples such as surface water, sediment, suspended particles, and biota.
Water samples are extracted using solid-phase extraction cartridges that adsorb PCBs as the water samples flow through the cartridge. Filterable suspended particles, sediments and biota are extracted using QuEChERS extraction procedures.
PCB concentrations are determined by calibrating a gas chromatograph-mass spectrometer with pure standards to create a calibration standard curve to use to quantify PCBs in the cleaned up sample extracts.
Current interest in PCBs is to determine the concentrations of dioxin-like PCBs that are the most toxic to human and environmental health.
They include:
| IUPAC Name (PCB Congener number) | CAS Number |
| 3,3′,4,4′,5,5′-Hexachlorobiphenyl (169) | 32774-16-6 |
| 3,3′,4,4′,5-Pentachlorobiphenyl (126) | 57465-28-8 |
| 3,3′,4,4′-Tetrachlorobiphenyl (077) | 32598-13-3 |
| 3,4,4′,5-Tetrachlorobiphenyl (081) | 70362-50-4 |