Humans are exposed to mixtures of polyhalogenated dibenzo-p-dioxins, dibenzofurans, and biphenyls mainly through the diet. Many of these chemicals are dioxin-like and their relative toxicity is related to their ability to bind and activate the Ah receptor. The present study examines the structure-activity relationship for disposition of these chemicals in female B6C3F1 mice following subchronic exposures. Mice were treated 5 days/week for 13 weeks by oral gavage with different doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD),2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlorodibenzofuran (1-PeCDF), 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF), octachlorodibenzofuran (OCDF), 3,3',4,4',5-pentachlorobiphenyl (126), 3,3',4,4',5,5'-hexachlorobiphenyl (169), 2,3,3',4,4'-pentachlorobiphenyl (105), 2,3',4,4',5-pentachlorobiphenyl (118), and 2,3,3',4,4',5-hexachlorobiphenyl (156). All of the chemicals examined exhibited dose-dependent increases in the liver/fat concentrations except PCBs 105, 118, and 156. While TCDD is the most potent toxicant in this class of chemicals, 4-PeCDF, PeCDD, OCDF, TCDF, and PCB126 were sequestered in hepatic tissue to a greater extent than was TCDD. The high affinity for hepatic tissue supports the presence of an inducible hepatic binding protein for some dixin-like chemicals. The differences in disposition between these chemicals suggests that pharmacokinetic differences between congeners is important in the relative potency of these chemicals.

The USEPA and the USDA have completed the first statistically designed survey of the occurrence and concentration of CDDs and CDFs in the fat of beef animals raised for human consumption in the United States. Back fat was sampled from 63 carcasses at federally inspected slaughter establishments nationwide. The sample design called for sampling beef animal classes in proportion to national annual slaughter statistics. All samples were analyzed using a modification of EPA method 1613, using isotope dilution, High Resolution GC/MS to determine the rate of occurrence of 2,3,7,8-substituted CDDs/CDFS. The whole weight method detection limits ranged from 0.05 ng kg-1 for TCDD to 3 ng kg-1 for OCDD. The results of this survey showed a mean concentration (reported as I-TEQ, lipid adjusted) in U.S. beef animals of 0.35 ng kg-1 and 0.89 ng kg-1 when either non-detects are treated as 0 value or assigned a value of 1/2 the detection limit, respectively.

This paper presents the results of ambient air monitoring for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) performed during the 1992-1993 and 1993-1994 austral summers in the vicinity of McMurdo Station, Antarctica. Twenty-eight air samples were collected from four different locations to determine the identity and concentration of PCDD/PCDF compounds. PCDD/PCDF compounds were not detected at either the predominantly upwind location or a more remote site on Black Island. Trace levels of only a few PCDD/PCDF congeners were detected sporadically at a location approximately 500 m downwind of the station. The most frequent, most varied, and highest levels of PCD Ds/PCDFs were measured at a ''downtown'' location, where concentrations of total PCDDs ranged from 0.12 to 1.80 pg/m(3) and total PCDFs ranged from less than 0.02 to 2.77 pg/m(3). The data indicate that there are combustion sources at McMurdo other than the solid waste incinerator (power pla nts, vehicles, heating furnaces, etc.)that contribute PCDD/PCDF compounds to the ambient air. The greatest variety and highest concentration of PCDD/PCDF congeners measured in 1992-1993 during incineration of selected solid wastes implicates the interim incinerator as the likely source of the increased presence of these compounds in air. Results from the remote Black Island site indicate that the background Antarctic air is still ''free'' of PCDD/PCDF compounds (not detectable at current method detection limits in the sub-pg/m(3) range).

As part of the U.S. EPA Dioxin Reassessment Program, the 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and furans were measured at part per trillion (ppt) levels in beef fat collected from slaughter facilities in the United States. This is the first statistically designed national survey of these compounds in the U.S. beef supply. Analyte concentrations were determined by high-resolution gas chromatography/high-resolution mass spectrometry, using isotope dilution methodology. Method limits of detection on a whole weight basis were 0.05 ppt for TCDD and 0.10 ppt for TCDF, 0.50 ppt for the pentas (PeCDDs/PeCDFs)/hexas (HxCDDs/HxCDFs)/heptas (HpCDDs/HpCDFs), and 3.00 ppt for the octas (OCDD/OCDF). Method detection and quantitation limits were established on the basis of demonstrated performance criteria utilizing fortified samples rather than by conventional signal-to-noise or variability of response methods. The background subtraction procedures developed for this study minimized the likelihood of false positives and increased the confidence associated with reported values near the detection limits. Mean and median values for each of the 2,3,7,8-Cl-substituted dioxins and furans are reported, along with the supporting information required for their interpretation. The mean toxic equivalence values for the samples are 0.35 ppt (nondetects = 0) and 0.89 ppt (nondetects = 1/2 LOD).

Four samples of Chloranil and one sample of Carbazole Violet were analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans. Part per billion and part per million levels of hepta- and octachlorinated dioxins and furans were found in the samples. Hexachlorinated dioxins and furans were also found in some of the samples. These levels are considered minimum levels since the extraction and analytical procedures were not optimized for these samples containing such extremely high concentrations.

General Metals Works PS-1 PUF air samplers and an analytical method based on high resolution gas chromatography - high resolution mass spectrometry (HRGC-HRMS) were evaluated for determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/PBDFs) and bromo/chloro dibenzo-p-dioxins and dibenzofurans (BCDDs/BCDFs) in ambient air. Dilute solutions of these compounds and 13C12-1,2,3,4-TCDD were used to spike the filters of PS-1 air samplers which were then operated 24 hr to sample 350–400 m3 ambient air. After sampling, each quartz-fiber filter and polyurethane foam (PUF) were spiked with 13C12-labeled PCDD, PCDF, PBDD, and PBDF internal standards before separate Soxhlet extractions with benzene. The extracts were subjected to an acid/base clean-up procedure followed by clean-up on microcolumns of silica gel, alumina, and carbon and then analyzed by HRGC-HRMS. Results derived from this study indicated the PS-1 ambient air samplers and the analytical procedures were very efficient and that pg/m3 and sub-pg/m3 levels of total PCDDs/PCDFs, PBDDs/PBDFs, BCDDs/BCDFs, and 2,3,7,8-substituted congeners could be accurately measured. Background levels of these compounds in the ambient air were also determined. Total PCDDs, PCDFs, TBDFs, and PeBDFs were detected in a low concentration range of 0.3 to 3.0 pg/m3.

This paper describes the analytical procedures, results and identification of bromo/chloro dibenzo-p-dioxins and dibenzofurans in ash samples from several types of combustion and incineration processes.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in human milk, at the 0.1-10 parts-per-trillion level: method validation and survey resultsR. G. Heath, R. L. Harless, M. L. Gross, P. A. Lyon, A. E. Dupuy, and D. D. McDanielCite this: Anal. Chem. 1986, 58, 2, 463–468Publication Date (Print):February 1, 1986Publication History Published online1 May 2002Published inissue 1 February 1986https://pubs.acs.org/doi/10.1021/ac00293a044https://doi.org/10.1021/ac00293a044research-articleACS PublicationsRequest reuse permissionsArticle Views70Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMethods for the quantitative determination of multiple, specific polychlorinated dibenzo-p-dioxin and dibenzofuran isomers in human adipose tissue in the parts-per-trillion range. An interlaboratory studyP. W. Albro, W. B. Crummett, A. E. Dupuy, M. L. Gross, M. Hanson, R. L. Harless, F. D. Hileman, D. Hilker, C. Jason, and . et al.Cite this: Anal. Chem. 1985, 57, 13, 2717–2725Publication Date (Print):November 1, 1985Publication History Published online1 May 2002Published inissue 1 November 1985https://pubs.acs.org/doi/10.1021/ac00290a063https://doi.org/10.1021/ac00290a063research-articleACS PublicationsRequest reuse permissionsArticle Views67Altmetric-Citations34LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Validated sample preparation procedures and high resolution gas chromatography-high resolution mass spectrometry techniques were utilized for the quantitative measurement of 4 to 695 pg/g (ppt) levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378-TCDD) in the edible portions of fish from the state of Michigan. The methodology and the analytical results are presented.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSample preparation and gas chromatography-mass spectrometry determination of 2,3,7,8-tetrachlorodibenzo-p-dioxinR. L. Harless, E. O. Oswald, M. K. Wilkinson, A. E. Dupuy Jr., D. D. McDaniel, and Han TaiCite this: Anal. Chem. 1980, 52, 8, 1239–1245Publication Date (Print):July 1, 1980Publication History Published online1 May 2002Published inissue 1 July 1980https://pubs.acs.org/doi/10.1021/ac50058a019https://doi.org/10.1021/ac50058a019research-articleACS PublicationsRequest reuse permissionsArticle Views218Altmetric-Citations54LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts