Polychlorodibenzo-/?-dioxins

Polychlorodibenzo- -dioxins Perinatal Effects and the Dominant Lethal Test in Wistar Rats... 

A consistent pericardial edema in chickens gave rise to the term chick edema disease (chick edema factor) (I). Two known outbreaks of the disease in the broiler industry resulted in a great loss of chickens. A lipid residue from the manufacturing fatty acids, being used as a feed ingredient, was a principal source of the toxic substance. Contamination of the lipid component with polychlorodibenzo-p-dioxins was attributed as the causal agent. 

Firestone, D., M. Clower, Jr., A.P. Borsetti, R.H. Teske, and P.E. Long. 1979. Polychlorodibenzo-p-dioxin and pentachlorophenol residues in milk and blood of cows fed technical pentachlorophenol. Jour. Agric. Food Chem. 27 1171-1177. 

The name of PCDD/Fs or dioxins is given to a family of compounds of different number of chlorine atoms in the molecules (congeners). Totally, there are 75 of polychlorodibenzo-p-dioxins and 135 polychlorodibenzo-p-furans that might be formed. Almost all of them have been found in the environmental matrices (air, soil, sediments and animals tissue) and abiotic... 

This technique has been used for the determination of polychlorobiphenyls, polychlorodibenzo-p-dioxins, polychlorodibenzofurans, alkyl phosphates, chlorinated insecticides, organophosphorus insecticides, triazine herbicides. Dacthal insecticide, insecticide/herbicide mixtures, mixtures of organic compounds and organotin compounds in soils, and polyaromatic compounds, polychlorobiphenyls, chlorinated insecticides and organotin compounds in non-saline sediments and anionic surfactants in sludges. 

In non-saline sediments aliphatic and polyaromatic hydrocarbons, phthalate esters carboxylic acids, uronic acid aldoses chloroaliphatics haloaromatics chlorophenols chloroanisoles polychlorobiphenyls polychlorodibenzo-p-dioxins poychlorodibenzofurans various organosulphur compounds, chlorinated insecticides, organophosphorus insecticides mixtures of organic compounds triazine herbicides arsenic and organic compounds of mercury and tin. 

Von Bavel et al. [55] used a solid phase carbon trap in conjunction with supercritical fluid chromatography for the simultaneous determination of polychlorobiphenyls, pesticides, polychlorodibenzo-p-dioxins and polychlorodibenzofurans in soils. 

More recently, however, investigations into the formation and occurrence of polychlorodibenzofurans suggest that this family of toxic compounds may commonly occur at comparable or greater levels than the dibenzo dioxins and could generally pose a greater hazard than polychlorodibenzo-p-dioxins. Polychlorodibenzofurans are often found as cocontaminants in and are readily produced from pyrolysis of polychlorobiphenyls [83, 99-102], Most important, the... 

Pentachlorophenol, a large-volume fungicide and wood preservative, contains relatively high levels of hexa-, hepta- and octachlorodibenzodioxins and essentially no tetrachlorodibenzo-p-dioxins [83-85] and polychlorodibenzo-p-dioxin incineration of materials containing chlorophenols readily produces mixtures of polychlorodibenzo-p-dioxins, but 2,3,7,8-tetrachlorodibenzo-p-dioxin is a minor component. On the other hand, the highly toxic 1,2,3,7,8-pentachloro isomer is a major component of polychlorodibenzo-p-dioxins and polychlorodibenzofurans usually produce mixtures of distinctly different relative component abundances [83], On the other hand, the preferential accumulation of certain isomers in animals may prevent source identification from analyses of biological samples. 

A good example of the application of gas chromatography-mass spectrometry to the determination of polychlorodibenzo-p-dioxin and dibenzofurans up to the octochlorocogeners in soils and sediments is that of Smith et al. [110] which, it is claimed, is sufficiently sensitive to determine down to 1-5 parts per trillion of these substances. 

Representative multiple ion mass chromatograms of soil samples are presented in Fig. 5.4. These gas chromatography-mass spectrometric determinations of polychlorodibenzo-p-dioxin and polychlorodibenzofurans, and non-ortho polychlorobiphenyls in differing types of samples serve to exemplify the versatility of the procedure for such analyses. The gas chromatography-mass spectrometric data were usually uncluttered by extraneous components, and interpretation of the data was routinely straightforward. 

Von Bavel et al. [55] have developed a solid phase carbon trap (PX-21 active carbon) for the simultaneous determination of polychlorodibenzo-p-dioxins and polychlorodibenzofurans also polychlorobiphenyls and chlorinated insecticides in soils using superfluid extraction liquid chromatography for the final determination. Supercritical fluid extraction with carbon dioxide has been applied to the determination of dioxins in soil [114],... 

Various workers have discussed methodology for the determination of polychlorodibenzo-p-dioxins and dibenzofurans in sediments [110, 111, 115] and silts [109]. The method described by Smith et al. [110] for the determination of polychlorodibenzo-p-dioxins and dibenzofurans in soils and discussed in section 5.7.1.1 is also applicable to sediments. Taguchi [112] presented preliminary results obtained in a round robin inter-... 

Namiesnik et al. [33] have reviewed the analysis of soils and sediments for organic contaminants. They discuss methods of sample preparation and isolation-preconcentration prior to instrumental determination. Compound classes discussed include volatile organic compounds, polychlorobiphenyls, polyaromatic compounds, pesticides and polychlorodibenzo-p-dioxins and polychlorodibenzofurans. 

It has been observed that pyrolysis of polychlorodiphenyl ethers in the presence of air at 600°C produces low yields of polychlorodibenzofurans, as well as polychlorodibenzo-p-dioxins, which were identified by GC-MS methods. The major reaction pathways leading to dibenzofuran formation involve loss of hydrogen and hydrogen chloride from the o,o -positions. 

Miellet [80] and Lopez-Avila et al. [81] have reviewed the applications of Soxhlet extraction to the determination of pesticides in soil. This technique has been applied extensively to the extraction of polycyclic aromatic hydrocarbons, volatile organic compounds, pesticides, herbicides and polychlorodibenzo-p-dioxins in soils. Details of the extraction procedures and the analytical finish employed are reviewed in Table 1.1. 

Polychlorodibenzo p-dioxins and benzofurans Comparison of Soxhlet extraction using (a) toluene and (b) methylene dichloride-acetone [90,103]... 

Electrophilic substituent factors for the -C6H5 XC1X and -OC6H5 XC1X groups, needed to calculate the OH radical addition rate constants for polychlorinated biphenyls (PCBs), polychlorodibenzo-p-dioxins (PCDDs), and polychlorodibenzofurans (PCDFs), appear in Atkinson (1996), with discussion of an approach to calculating the rate constants for the PCDDs and PCDFs. The room temperature rate constants for the reactions of the OH radical with phenanthrene and anthracene, recently measured by Kwok et al. (1994,1997), are lower by factors of 2.5-8 than the previous recommendations and rate data (Biermann et al., 1985 Atkinson, 1989), casting doubt on the previously proposed correlation between the OH radical addition rate constant and ionization potential (Biermann et al., 1985). 

Choudhary, G.G., Webster, G.R.B. (1986) Photochemical quantum yields and sunlight half-lives of polychlorodibenzo-p-dioxins in aquatic systems. Chemosphere 15, 1935-1940. 

Govers, H.A.J., Luijk, R., R., Evers, E.H.G. (1990) Calculation of heat of vaporization, molar volume and solubility parameter of polychlorodibenzo-p-dioxins. Chemosphere 20, 287-294. 

Choudhry GG, Webster GRB. 1987. Quantum yields of polychlorodibenzo-p-dioxins in water-acetonitrile mixtures and their environmental phototransformation rates. In Zika RG, Cooper WJ, eds. Photochemistry of environmental aquatic systems. Washington, DC American Chemical Society, 327 61-74. 

Cull MR, Dobbs AJ, Goudot M, et al. 1984. Polychlorodibenzo-p-dioxins and dibenzofurans in technical pentachlorophenol - results of a collaborative analytical exercise. Chemosphere 13 1157-1165. 

Hass JR, Friesen MD, Parker CE, et al. 1977. Use of negative-ion chemical ionization mass spectrometry in the determination of polychlorodibenzo-p-dioxins at the part-per-trillion level in tissue samples. Environ Health Perspect 20 246. 

Jensen AA. 1987. Polychlorobiphenyls (PCBs), polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) in human milk, blood and adipose tissue. Sci Total Environ 64 259-293. 

Khera KS, Ruddick JA. 1973. Polychlorodibenzo-p-dioxins Perinatal effects and the dominant lethal test in Wistar rats. Advances in Chemistry Series 12C 70-84. 

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