ABSTRACT
Polychlorinated biphenyls (PCBs) are a class of chlorosubstituted biphenyl compounds that were once widely used as additives in transformer oils, lubricating oils, and hydraulic fluids. This chapter lists the common Aroclors, their Chemical Abstract Service (CAS) numbers, and the chlorine contents. Gas chromatography (GS)/mass spectrometry (MS) is the best confirmatory method to positively confirm the presence of PCBs, especially in heavily contaminated samples. Aqueous and nonaqueous samples must be extracted into a suitable solvent prior to their analysis. Electron capture detector (ECD) is the most commonly used detector for trace level analysis of PCBs by GC, exhibiting a response to an amount below 0.1 ng PCBs. Although GC/MS is the most reliable technique for qualitative determination of PCBs, its quantitative estimation in environmental samples are more accurately done from the analysis by GC-ECD. Sample cleanup often becomes necessary to remove interfering substances such as phthalate esters and many chlorinated compounds frequently found in wastewater, sludge, and solid waste.
