Polychlorinated biphenyls Subject

Sonication of polychlorinated biphenyls (PCBs) from soils has been the subject of an interlaboratory study [196] with 129 participants. Two standard methods of extraction were evaluated EPA method 3540 for Soxhlet extraction and EPA method 3550 for sonication... 

The use and disposal of polychlorinated biphenyls (PCBs) are regulated by the TSCA. In addition to the RCRA used oil management standards, marketers and burners of used oil contaminated with any quantifiable level of PCBs are subject to the current TSCA requirements, which provide comprehensive management standards for such used oils. 

This book examines comprehensively the chlorine industry and its effects on the environment. It covers not only the history of chlorine production, but also looks at its products, their effects on the global environment and the international legislation which controls their use, release and disposal. Individual chapters are dedicated to subjects such as end use processes, water disinfection and metallurgy, environmental release of organic chlorine compounds, polychlorinated biphenyls, legal instruments and the future of the chlorine industry. 

Based on the examination of analytical data from polychlorinated biphenyls (PCBs), OCPs and PAHs spiked into SPMDs, which have subsequently been subjected to the entire SPMD analytical procedure described herein, recoveries are generally >75% with good precision (i.e., C.Fs < 20%). Surprisingly, the C. Vis for the analysis of contaminants present in replicate SPMDs deployed contiguously at the same sites and treated identically during analysis are often equivalent to C.Fs of SPMD spikes. This observation suggests that the variability of analyte sampling rates of replicate SPMDs in the field is small and that the analytical methods used for field-deployed SPMDs are robust. 

In activated sludge, 80.6% degraded after a 47-h time period (Pal et al., 1980). Chemical/Physical. Zhang and Rusling (1993) evaluated the bicontinuous microemulsion of surfactant/oil/water as a medium for the dechlorination of polychlorinated biphenyls by electrochemical catalytic reduction. The microemulsion (20 mL) contained didodecyldi-methylammonium bromide, dodecane, and water at 21, 57, and 22 wt %, respectively. The catalyst used was zinc phthalocyanine (2.5 nM). When PCB-1221 (72 mg), the emulsion and catalyst were subjected to a current of mA/cm on 11.2 cm lead electrode for 10 h, a dechlorination yield of 99% was achieved. Reaction products included a monochlorobiphenyl (0.9 mg), biphenyl, and reduced alkylbenzene derivatives. 

Synthetic musks have been detected in human tissues (Table 8) due to their lipophilic nature and their low biodegradability. The occurrence of these fragrance-related chemicals is subjected to a variable pattern with substantial interindividual differences, opposed to other environmental contaminants such as polychlorinated biphenyls (PCBs) or pesticides [165]. 

GC-MS can be used to analyze organochlorine pesticides, for example, a-, [3-, y-HCH, HCB, and polychlorinated biphenyls (PCB). The components are quantified by using an internal standard. Furthermore, a calibration is performed with a standard mixture containing known concentrations of the components to be measured and one or more components not contained in the sample (internal standards). The calibration is followed by injection of the sample containing known amounts of internal standards. Quantification is relative to the internal standard. In this way, the sample extract volume will not be included in the calculations, and it is not necessary to accurately determine the final sample volume after evaporation of the injection volume. The GC-MS instrument should be calibrated every day. The sensitivity of the mass spectrometer can, for instance, be controlled daily by determining the signal-to-noise ratio for a given amount of a chosen component (PCB-101 could be one such component). For further details of the method, the reader is referred to different manuals and papers on the subject.417... 

In this chapter we shall discuss LCA in the context of protocols for the analysis of polychlorinated biphenyl (PCB) and polycyclic aromatic hydrocarbon (PAH) in surface water using two different extraction techniques,11 and the LCA of the utilization of different solvents.12-26 Generally speaking, this is the beginning of the use of LCA to assess the environmental impact of analytical protocols at the moment, there are not many papers on this subject, but this situation is sure to improve in the near future. 

Regardless of one s position in this debate, it is apparent that the use of compounds that show persistence in the environment must be carefully examined and monitored. Any compound that is persistent and hydrophobic (lipophilic or fat soluble) will be subject to the process of biomagnification and may present special problems. In addition to DDT and other chlorinated pesticides, another example is provided by the polychlorinated biphenyls (PCBs). These compounds have two benzene rings bonded together, with varying numbers of chlorines substituted on the rings. One example is provided by the following structure ... 

One essentially unexplored area for hair analysis is its application to the investigation of environmental toxin exposure. We received a research grant during 1979 from the National Institute of Occupational Safety and Health to explore the possibility of using hair analysis for monitoring exposure to polychlorinated biphenyl compounds (PCBs). Although the analytical chemical problems of this project were successfully solved, we were unable to mount successful field studies with human subjects. 

Polychlorinated biphenyls (PCBs) and dioxins are also of special interest. The biphenyl group is able to serve some microorganisms as their carbon and energy source, and thus the mono-, di-, tri-, and tetrachloro biphenyls are, to some degree, subject to biodegradation. However, in more extensively chlorinated biphenyls, the substituents prevent ring hy-droxylation. See Figure 9.14. 

Much more emphasis must be placed upon this subject of the identification of trace constituents. The problem that the polychlorinated biphenyls present in the analysis of organochlorine pesticides has been illustrated. This is just one example of the need to identify accurately a very wide range of chemical compounds in extremely small concentrations. 

Polychlorinated biphenyls (PCB) - currently banned compounds - were formerly used in hydraulic fluids, plasticizers, adhesives, fire retardants, and pesticide extenders. These contaminants are persistent in the environment and are present in sediments at the bottom of lakes, rivers, and seas. As they exhibit carcinogenic and endocrine-disrupting activity, they are subject to regulation. For instance, in the United States, the maximum allowed concentration of PCBs in drinking water is 0.5 ng mL [21]. 

Articles are exempt from various provisions of the TSCA, including (1) a person who imports or processes a chemical substance subject to specific information-gathering rules under 40 CFR Part 704 is exempt from reporting and recordkeeping rules to the extent that the chemical substance is imported or processed solely as part of an article [12] (2) notices of export are not required for articles, except for polychlorinated biphenyl (PCB) articles and other articles that EPA specifically makes subject to export notice requirements [13] ... 

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