Polychlorinated biphenyls records

M Company, 2000. Phase-out Plan for POSF-based products U.S. EPA Administrative Record AR226-0588. U.S. Environmental Protection Agency, Washington, DC. Achman, D.R., Hornbuckle, K.C., Eisenreich, S.J., 1993. Volatilization of polychlorinated biphenyls from Green Bay, Lake Michigan. Environ. Sci. Technol. 27, 75-87. 

The Mixture of Concern Approach This approach can be used only if adequate toxicity data on the specific chemical mixture of concern are available. Having the data means that sufficient and appropriate experimental testing has been done and that the results are on record about this mixture s toxicity. This is the most direct and simplest approach, with the fewest uncertainties to derive a criterion or acceptable level for stable mixtures such as fuel oils, jet fuels, mixtures of polychlorinated biphenyls (PCBs), and polybrominated biphenyls (PBBs) [10]. However, working from available data may leave uncertainties about the precise composition of a mixture undetermined. Very few mixtures other than those mentioned above have been studied adequately for toxicity assessment. Hence this data-mining approach is the least frequently used method. 

Swackhamer DL, Armstrong DE. 1986. Estimation of the atmospheric and nonatmospheric contributions and losses of polychlorinated biphenyls for Lake Michigan on the basis of sediment records of remote lakes. Environ Sci Technol 20 879-883. 

Maximum concentrations of polycyclic aromatic hydrocarbons (PAHs) were recorded at Bela Stena in 1997 and reached 0.10 pg L , while the average value was 0.04 pg L . Polychlorinated biphenyls (PCBs) were not found in the water in measurable quantities during the 5-year period. 

The detection and quantification of polychlorinated dibenzo-p-dioxins, and in particular the 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (2,3,7,8-TCDD), is a major application for double-focusing magnetic-sector mass spectrometers. Despite extensive clean-up procedures, samples still contain compounds such as polychlorinated biphenyls and benzyl phenyl ethers, which have the same nominal masses as the compounds of interest. The sample is spiked with a known amount of the isotope labelled form of 2,3,7,8-TCDD, introduced via gas chromatography and recorded by high-resolution mass spectrometry. The measurement is quantified by comparison of the native dioxin response to that from the C-labelled form, and verified by confirmation of the ratio of the major isotopes of both the native and the C-labelled dioxins. At 10 000 resolving power (10% valley definition) the detection level for 2,3,7,8-TCDD is about 1 femtogram, or 3 attomole (Figure 6). 

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