Polychlorinated diphenyl ethers

C. Rappe and R. Lindahl, "Formation of Polychlorinated Dibenzofurans (PCDFs) and Polychlorinated Dibenzo-p-Dioxins (PCDDs) from the Pyrolysis of Polychlorinated Diphenyl Ethers,"Chemosphere, 2, 351 (1980). 

Fig. 7 Generic chemical structures of polyhalogenated compounds. X=C1, Br. (I) Polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs) (II) chlorophenols (CPs), bromophenols (BPs) (III) polychlorinated diphenyl ethers (PCDE), polybrominated diphenyl ethers (PBDE) (IV) polychlorinated dibenzo-p-dioxin (PCDD), polybrominated dibenzo-p-dioxin (PBDD) (V) polychlorinated dibenzofuran (PCDF), polybrominated dibenzofuran (PBDF) (VI) tetrabromobisphenol A (TBBPA)...

Lyytikainen, M. Rantalainen, A.-L. Mikkelson, P. Hamalainen, H. Paasivirta, J. Kukkonen, J.V.K. 2003b, Similarities in bioaccumulation patterns of polychlorinated dibenzo-p-dioxins and fu-rans and polychlorinated diphenyl ethers in laboratory-exposed oligochaetes and semipermeable membrane devices and in field-collected chironomids. Environ. Toxicol. Chem. 22 2405-2415. 

Howie L, Dickerson R. Davis D. et al. 1990. Immunosuppressive and monooxygenase induction activities of polychlorinated diphenyl ether congcrers in C57BL/6N mice quantitive structure-activity relationships. Toxicol Appl Phamiacol 105 254-263. 

Mamantov A. 1985. Tire photolysis of polychlorinated diphenyl ethers and chloroanisoles may proceed via carbenes. Chemosphere 14(6/7) 905-908. 

Kerkvliet, N.I., Brauner, J.A. Matlock, J.P. (1985) Humoral immunotoxicity of polychlorinated diphenyl ethers, phenoxy phenols, dioxins and furans present as contaminants of technical grade pentachlorophenol. Toxicology, 36, 307-324... 

Koistinen, J., Stenman, O., Haahti, H., Suonpera, M., Paasivirta, J., 1997. Polychlorinated diphenyl ethers, dibenzo-p-dioxins, dibenzofurans and biphenyls in seals and sediments from the Gulf of Finland. Chemosphere 35, 1249-1269. 

Other than those listed elsewhere includes chlorophenylphenyl ethers, bromophenylphenyl ethers, bis(dichloroisopropyl) ether, bis(chloroethoxy)methane, and polychlorinated diphenyl ethers. 

HRGC/MS methods (40-102%) (Creaser and Al-Haddad 1989 Donnelly et al. 1986 Simon et al. 1989). Polychlorinated biphenyls, polychlorinated diphenyl ethers, polychlorinated naphthalenes, and polychlorinated alkydibenzofurans may be found at concentrations several orders of magnitude higher than the analytes of interest (EPA 1994a) and could thus interfere with the CDDs. Retention times must be verified using reference standards. 

Handbook of Chemistry and Physics" (1983), 63. Edition, CRC Press, Boca Raton Kurz J, Ballschmiter K (1995), Fresenius J. Anal. Chem. 351 98-109. Isomer-specific determination of 79 polychlorinated diphenyl ethers (PCDE) in cod liver oils, chlorophenols and in a fly ash" Nestrick TJ, Lamparski LL, Crummett WB (1987), Chemosphere 16 777-790. Thermolytic surface reaction of benzene and iron(III) chloride to form chlorinated dibenzo-p-dioxins and dibenzofurans"... 

Any compound that yields ions listed in Table 5 and also elutes within the retention time window of the corresponding homologue is a potential interference. PCDDs/PCDFs are often associated with other chlorinated compounds such as polychlorinated biphenyls (PCBs) and polychlorinated diphenyl ethers (PCDPEs). These compounds may be found at concentrations several orders of magnitude higher than that of the analytes of interest and may otherwise interfere with the analysis of PCDDs/PCDFs. Therefore the retention time of the target analytes must be verified using reference standards and compared to retention time... 

The ions at m/z 376 (HxCDPE), 410 (HpCDPE), 446 (OCDPE), 480 (NCDPE) and 514 (DCDPE) represent the polychlorinated diphenyl ethers. 

Dioxins and furans are not produced deliberately, but are produced unintentionally as byproducts of combustions of organic matter in the presence of chlorine. Dioxins and fiirans consists of 135 possible chlorinated dibenzoftnan and 75 chlorinated dibenzo-p-dioxins with Irom 1 to 8 chlorine substituents (Figure 18.2). PCDDs/DFs are found as byproducts during the manufacture of some industrial chemicals such as PCBs, polychlorinated naphthalenes, chlorinated phenols, chlorinated phenoxyacids, polychlorinated diphenyl ethers, polyvinyl chlorides, and chlorinated phenoxy-2-phenols (Hutzinger et al, 1985 Hryhorczuk et al, 1986 ATSDR, 2001 Masunaga et al. 

Table 16. Chemical name, chemical structure, molecular formula, molecular mass, water solubility (WS), n-octanol/water partition coefficient (log Kow)> and estimated or predicted bioconcentration factors on a wet weight basis (BCF ) and on a lipid basis (BCFl) of Polychlorinated Diphenyl Ethers (PCDEs) in fish and mussel... 

Polychlorinated diphenyl ethers (PCDE) are common impurities in chlorophenol formulations, which were earlier used as fungicides, slimicides, and as wood preservatives. PCDEs are structurally and by physical properties similar to polychlorinated biphenyls (PCB). They have low water solubility and are lipophilic. PCDEs are quite resistant to degradation and are persistent in the environment. In the aquatic environment, PCDEs bioaccumulate. These compounds are found in sediment, mussel, fish, bird, and seal. PCDEs show biomagnification potential, since levels of PCDEs increase in species at higher trophic levels. PCDEs are also detected in human tissue. Despite the persistence and bio accumulation, the significance of PCDEs as environmental contaminants is uncertain. The acute toxicity and Ah-receptor-me-diated (aryl hydrocarbon) activity of PCDEs is low compared to those of polychlorinated di-benzo-p-dioxins (PCDD) and dibenzofurans (PCDF). Due to structural similarity to thyroid hormone, PCDEs could bind to thyroid hormone receptor and alter thyroid function. Furthermore, PCDEs might be metabolized to toxic metabolites. In the environment, it is possible that photolysis converts PCDEs to toxic PCDDs and PCDFs. 

OH-PCDE Hydroxyl-derivates of polychlorinated diphenyl ethers... 

Polychlorinated diphenyl ethers (PCDE), also called bis(chlorophenyl) ethers and chlorodiphenyl oxides, are neutral aromatic compounds which resemble structurally polychlorinated biphenyls (PCB), except that one oxygen atom connects the phenyl rings. The empirical formula of the PCDEs is C12H10 nClnO, where n = 1-10. The structural formula of the PCDEs is given in Fig. 1. 

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