Recent advances in PCB analysis

Abstract

In recent years it has become apparent that one of the more widespread and persistent chemical contaminants in the environment is the polychlorinated biphenyls group (PCBs). These industrial materials are now found in almost all bodies of water, sediments of rivers, lakes, and streams in soil samples, as well as in many fish, animals, and man. Their effects within biological systems over prolonged periods of time suggest the possibility of serious disturbances in living creatures and plants. Thus, the monitoring of PCBs for both presence and amounts has become a widespread endeavour around the world, and can be expected to increase in necessity as the overall effects of PCBs become more apparent. Many private, governmental, and industrial laboratories are currently engaged in routine analyses for PCBs in a variety of environmental samples. Most of the currently used analytical methods for PCB analysis have evoled during the past ten years, and these rely heavily on evolved time-consuming, and often inefficient procedures for the extraction separation, and quantitative determination of the various PCB formulations used commercially. These methods have all relied on physical manipulations for the separation of the PCBs from all other environmental contaminants, followed by vapor phase chromatography (VPC) for the quantitative determination. In recent years, with the evolution of high pressure liquid chromatography (HPLC), procedures have been perfected for the rapid, simple, and reproducible separation of all PCBs from other organic and inorganic pollutants. Thus, using sequential column HPLC, it is now possible to separate the PCBs rapidly from other organics found in fish, water, birds, and other biological samples, as well as to then separate these PCBs from all other chlorinated hydrocarbons that may have been present in the original sample. A quantitative analysis for the fully separated PCBs can then be accomplished using either VPC with flame ionization (FID) or electron capture detection (ECD). It is also now possible to use HPLC combined with dual detectors in series for the complete quantitative analysis of PCBs. Even ECD can now be regularly used with HPLC equipment. It is no longer necessary to recover any eluents from the HPLC for eventual VPC work, and the final quantitative and qualitative analyses can be done directly on the HPLC at the time that the final separation of the PCBs is being accomplished. Combining the above-described developments in PCB analysis with certain minicomputer facilities now available will allow for the greatly improved analysis of PCBs. Requirements for manpower, time, machinery, solvents, chemicals, and space have all been greatly reduced during the past few years and the future should see a rapid acceptance and improvement of these newer analytical methods for PCB analysis.