William H. Newsome

Study of chlorinated diphenyl ethers and chlorinated 2-phenoxyphenols as interferences in the determination of chlorinated dibenzo-p-dioxins and chlorinated dibenzofurans in biological samples

Two classes of environmentally occurring chlorinated aromatic hydrocarbons which have mass spectral properties similar to the chlorinated dibenzo-p-dioxins (dioxins) and chlorinated dibenzofurans (furans) were studied. Standards of chlorinated diphenyl ethers (CDEs), and chlorinated 2-phenoxyphenols (CPPs) and their methyl ethers, along with the dioxins and furans were passed in steps through a simple method for the analysis of the latter compounds in biological samples. The CDEs, which interfere with the determination of furans by mass spectrometry, had similar extraction, high-performance liquid chromatographic and gas chromatographic properties as the furans but, in all cases studied, were well separated from them on an activated Florisil column using combinations of hexane and dichloromethane as eluting solvents. The higher CPPs on the other hand tended to generate dioxin residues by ring closure when exposed to strong hydrochloric acid solution during sample preparation. In addition, their methyl ethers containing four to six chlorines tracked completely through all stages of the method with the dioxins. Thus, if the methyl ethers of CPPs were present in a sample extract, additional mass spectral information would be needed to further differentiate them from dioxins in environmental samples.

Radioimmunoassay of PCBs in Milk and Blood

Abstract A radioimmunoassay was developed capable of determining Aroclor 1260 in milk at levels of from 20 to 80 ppb and in blood from 2 to 16 ppb. The values obtained by radioimmunoassay correlate well with those determined by gas-liquid chromatography (r2 = 0.96 for milk and 0.99 for blood) but were lower. Antiserum was produced in rabbits and was specific for 2, 2′, 4, 4′, 5, 5′-hexachlorobiphenyl. It cross-reacted with congeners and isomers in Aroclor 1254 and 1260 to the extent that a 20% decrease in binding was observed with 0.1 ng of either mixture. The method requires preliminary cleanup of the extract on alumina and utilizes 25 % dimethyl sulfoxide in the assay medium to promote solubilization of the substrates.

Chlorinated compounds in tissues of chickens raised on pentachlorophenol‐contaminated litter

Broiler chickens were raised on commercial wood shavings containing 134 p.p.m. pentachlorophenol and on control litter consisting of corn-cob chips. Initial analysis of the wood-shaving litter showed the presence of hepta-, octa- and nonachlorinated diphenyl ethers, octa- and nonachlorinated 2-phenoxyphenols, and hepta- and octachlorinated dibenzodioxins. Analysis of liver, fat, and muscle tissue after nine weeks indicated the assimilation of these compounds with pentachlorophenol being present in the highest concentration. Chlorinated diphenyl ethers were detectable only in fat, while octa- and nonachlorinated 2-phenoxyphenols were found in all three tissues examined. While liver and fat contained hepta- and octachlorinated dibenzodioxins, no hexachlorinated congener was detected nor were significant amounts of dioxin found in muscle tissue. Although gross pathological examination of the birds did not indicate abnormalities, a mixed type of hepatic enzyme induction was observed in those birds raised on wood shavings.

A Method for the Determination of Octa- and Nonachloro-2-phenoxyphenols in Chicken Tissue

A gas-liquid chromatographic method was developed capable of determining octa- and nonachloro-2-phenoxyphenols in chicken liver or muscle at 0.25 ppb and fat at 2.5 ppb. The method involves extraction with acidified acetone:hexane, cleanup with concentrated H2SO4 and Florisil column chromatography, methylation with diazomethane, and quantitation by capillary column gas-liquid chromatography with electron capture detection. Fortification of liver and muscle at 0.25 or 0.5 ppb and fat at 2.5 or 5.0 ppb and subsequent analysis yielded recoveries averaging 91% for octa- and 97% for nonachlorophenoxyphenol.Abstract A gas-liquid chromatographic method was developed capable of determining octa-and nonachloro-2-phenoxyphenols in chicken liver or muscle at 0.25 ppb and fat at 2.5 ppb. The method involves extraction with acidified acetone:hexane, cleanup with concentrated H2SO4 and Florisil column chromatography, methylation with diazomethane, and quantitation by capillary column gas-liquid chromatography with electron capture detection. Fortification of liver and muscle at 0.25 or 0.5 ppb and fat at 2.5 or 5.0 ppb and subsequent analysis yielded recoveries averaging 91% for octa-and 97% for nonachlorophenoxyphenol.