Hexachlorobiphenyls

Cm.OROCARBONSANDCm.OROHYDROCARBONS - TOXIC AROMATICS] (Void) 2,2y,4,4y,5,6y-hexachlorobiphenyl... 

The enantioselective determination of 2,2, 3,3, 4,6 -hexachlorobiphenyl in milk was performed by Glausch et al. (21). These authors used an achiral column for an initial separation, followed by separation of the eluent fraction on a chiral column. Fat was separated from the milk by centrifugation, mixed with sodium sulfate, washed with petroleum ether and filtered. The solvent was evaporated and the sample was purified by gel permeation chromatography (GPC) and silica gel adsorption chromatography. Achiral GC was performed on DB-5 and OV-1701 columns, while the chiral GC was performed on immobilized Chirasil-Dex. 

The selection of these compounds was made on the grounds of their toxicity, environmental stability, and tendency to undergo biomagnification the intention was to move toward their removal from the natural environment. In the REACH proposals of the European Commission (EC published in 2003), a similar list of 12 POPs was drawn up, the only differences being the inclusion of hexachlorobiphenyl and chlordecone, and the exclusion of the by-products, dioxins, and furans. The objective of the EC directive is to ban the manufacture or marketing of these substances. It is interesting that no fewer than eight of these compounds, which are featured on both lists, are insecticides. 

Glausch, A., Hahn, J., Schurig, V. (1995). Enantioselective determination of chiral 2,2, 3,3,4,6 -hexachlorobiphenyl (PCB 132) in human milk samples by multidimensional gas chromatography/electron capture detection and by mass spectrometry. Chemosphere 30, 2079-2085. 

During the storage of the sample, loss of analyte can occur via vaporisation, degradation, and/or adsorption. Adsorption of trace organic and inorganic species in seawater to container walls can severely affect the accuracy of their determination. The adsorption of dichlorodiphenyltrichloroethylene [67] and hexachlorobiphenyl [68] onto glass containers has been observed. 

Lynch, T.R., H.E. Johnson, and W.J. Adams. 1982. The fate of atrazine and a hexachlorobiphenyl isomer in naturally-derived model stream ecosystems. Environ. Toxicol. Chem. 1 179-192. 

Interaction effects of PCDDs with other polychlorinated compounds or mixtures are not extensively documented. For example, certain polychlorinated hexachlorobiphenyls (PCBs) have a low toxic potency to induce cleft palate deformities in mice (Bimbaum et al. 1985). However, mixtures of 2,3,7,8-TCDD and 2,3,4,5,3, 4 -hexachlorobiphenyl resulted in a tenfold increase in incidence of cleft palate in mice. Thus, the toxicity of compounds such as 2,3,7,8-TCDD may be enhanced by compounds of relatively low acute toxicity, such as selected PCBs. Bimbaum etal. (1985) concluded that the widespread environmental occurrence of such combinations suggests a need for further evaluation of the mechanism of this interaction. 

The most prominent PCB congeners at 280 to 323 pg/kg DW in the tilefish (Lopholatilus chamaeleonticeps) from Georges Bank in 1981 to 1992 were PCBs 138 and 153 in gonad and liver. At 69 to 82 pg/kg DW, the most prominent PCB congeners in the tilefish from New Jersey during this same period were PCBs 138 and 153 in liver (Steimle etal. 1990). Total PCB concentrations in marine coastal fishes were dominated by the hexachlorobiphenyls (Knickmeyer and Steinhart 1989), but trout from isolated mountain lakes had tri-, tetra-, and pentachlorobiphenyls as the major components of total PCBs (Sanchez et al. 1993). 

Foster, E.P., N.H. Vrolijk, T.T. Chen, and L.R. Curtis. 1998. Interaction of 2,2,4,4,5,5,-hexachlorobiphenyl with hepatic cytochrome P-4501A in rainbow trout (Oncorhynchus mykiss). Jour. Toxicol Environ. Health 53A 313-325. 

Goldstein, J.A., J.D. McKinney, G.W. Lucier, P. Hickman, H. Bergman, and J.A. Moore. 1976. Toxicological assessment of hexachlorobiphenyl isomers and 2,3,7,8-tetrachlorodibenzofuran in chicks. II. Effects on drug metabolism and porphyrin accumulation. Toxicol. Appl. Pharmacol. 36 81-92. 

Marks, T.A., G.L. Kimmel, and R.E. Staples. 1981. Influence of symmetrical polychlorinated biphenyl isomers on embryo and fetal development in mice. I. Teratogenicity of 3,3, 4,4, 5,5 -hexachlorobiphenyl. Toxicol. Appl. Pharmacol. 61 269-276. 

Solbakken, J.E., K. Ingebrigtsen, and K.H. Palmork. 1984. Comparative study on the fate of the polychlorinated biphenyl 2,4,5,2,4,5,-hexachlorobiphenyl and the polycyclic aromatic hydrocarbon phenanthrene in flounder (Platichthys flesus), determined by liquid scintillation counting and autoradiography. Mar. Biol. 83 239-246. 

FJciureJyT. (a) Mass spectrum at the top of the chromatographic peak (b) background spectrum (c) analyte spectrum after background subtraction (d) library spectrum of hexachlorobiphenyl (score 99%). 

Peppriell J. 1981. The induction of hepatic microsomal mixed-function oxidase activities in the mouse by mirex, 3,4,5,3 ,4 ,5 -hexachlorobiphenyl, and equimolar dosages of both. Environ Res 26 402-408. 

Hexachlorobiphenyl Biphenyl chlorinated to a chlorine content of 60 weight percent 60 45... 

---