Joseph J. Breen

Mass spectral confirmation of chlorinated and brominated diphenylethers in human adipose tissues

Abstract This study has resulted in the detection and confirmation of polyhalogenated diphenylethers (PHDPEs) in human adipose tissues. The PHDPEs are commercially produced as brominated fire retardants and are known contaminants in some other commercial products, e.g., pentachlorophenol. The samples analyzed were selected from composites of the fiscal year 1987 National Human Adipose Tissue Survey (FY87 NHATS) repository. Identification of the PHDPEs was based on comparison of full scan mass spectra of the samples to the available standards, application of SIM techniques to compare theoretical ion ratios to observed ion ratios for characteristic ions, and measurement of fragment losses from the molecular ion clusters. Estimated concentrations were achieved through comparison of responses from the analysis of a PCDPE standard solution, the results of the analysis of two commercial fire retardants and the analysis of a decabromodiphenylether standard. All samples were found to contain detectable levels of the PHDPEs. The response profiles or patterns for both the chlorinated and brominated diphenylethers were consistent across all samples.

PCDDs and PCDFs in human adipose tissue from the EPA FY82 NHATS repository

Abstract Analysis for tetra- through octachloro-PCDDs and PCDFs was completed for 46 tissue samples prepared from the U.S. Environmental Protection Agency (EPA) National Human Adipose Tissue Survey (NHATS). The samples were prepared as composites from over 900 specimens to represent the nine U.S. census divisions and three age groups (0–14, 15–44, and 45 plus years). The data demonstrate that PCDDs and PCDFs are prevalent in the general U.S. population and that differences exist with age.

Determination of the prevalence of polychlorinated diphenyl ethers (PCDPES) in human adipose tissue samples

Abstract The HRMS analysis of human adipose tissues for PCDDs and PCDFs demonstrated responses representative of polychlorinated diphenyl ethers (PCDPEs). The responses correspond to hexathrough decachloro PCDPE isomers with lipid-based concentrations ranging as high as 2000 pg/g. The identification of the responses as PCDPEs is described, and estimates of residue levels are provided.

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Evaluation of an analytical method for the determination of polybrominated dibenzo-p-dioxinsdibenzofurans (PBDD/PBDF) in human adipose

An analytical method designed for the determination of chlorinated dibenzo-p-dioxins and dibenzofurans in human adipose tissue was extended to determine the brominated analogs. The method was evaluated by determining recoveries of 2,3,7,8-substituted, mass-labeled, and unlabeled tetra- through hexabrominated dioxins and furans.

Polychlorinated dibenzo-p-dioxin and dibenzofuran concentration levels in human adipose tissue samples from the continental United States collected from 1971 through 1987

Human adipose tissue samples collected through the U.S. Environmental Protection Agencys National Human Adipose Tissue Survey (NHATS) from 1971 through 1987 have been used in three different research programs to address body burden levels of polychlorinated dibenzo-p-dioxins and dibenzofurans. The study designs, analytical methods, and quality control procedures for each of the studies are compared. Data for 2,3,7,8-TCDD are summarized for the three studies.

Bromo- and bromochloro-dibenzo-p-dioxins and dibenzofurans in the environment

At least 36 million pounds of brominated flame retardants are used in the U.S. annually. Most if not all of these materials enter the waste stream via landfilled plastic waste, municipal incinerator fly ash, or automotive fluff waste. Analytical methodology is summarized which is suitable for environmental monitoring of these wastes, and the significance of the analytical results is discussed.

Determination of organic chemicals in human whole blood: preliminary method development for volatile organics

Extensive commercial, industrial, and domestic use of volatile organic chemicals, virtually assures that the general population will be exposed to some level of this class of chemicals. Because blood interacts with the respiratory system and is a major component of the body, it is likely that the analysis of blood will show exposure to volatile organics. Monitoring of the blood in conjunction with monitoring of xenobiotic levels in urine and adipose tissue is an effective way to assess the total body burden resulting from exposure to a chemical. This article introduces a method for the detection and confirmation of selected volatile organics at parts-per-trillion (ppt) levels in whole human blood. Intended for routine use, the method consists of a dynamic headspace purge of water-diluted blood where a carrier gas sweeps the surface of the sample and removes a quantifiable amount of the volatile organics from the blood and into an adsorbent trap. The organics are thermally desorbed from the adsorbent trap and onto the analytical column in a gas-chromatographic/mass-spectrometric (GC/MS) system where limited mass-scan data are taken for qualitative and quantitative identification. Method validation results and limited population-survey results are also presented here.

Principal component analysis and spatial correlation: Environmental analytical software tools

Abstract Using principal component analysis and geostatistics, the authors have reexamined the results of a study of chlorinated dibenzodioxins and dibenzofurans in Hamburg (Germany) Harbor sediments. These methods identified the same anomalous samples as the original study, but without recourse to the more difficultly obtained isomer-specific chemical analyses. In addition, they revealed in the remaining data a trend highly suggestive of two spatially and chemically discrete sources for nearly all (>90%) of the subject compounds found in the study, once again using no isomer-specific data. All of the above was done with readily available, public-domain software.

Correlation of graph-theoretical parameters with biological activity

Ośmialowski and Kaliszan calculated graph-theoretical indices for substituted isonicotinic hydrazides and used simple and multiple regression to search (unsuccessfully) for correlations with biological activity. The present paper describes successful searches for correlation in the same data set using principal component analysis (PCA) with multivariate outlier testing and also using stepwise multiple regression. Following PCA, correlation with biological activity always appeared in the second principal component, not the first, that is, after projection of the data points into the (n - 1)-space orthogonal to the first principal component axis. In that space, the principal component score was a more accurate predictor of biological activity than were equations provided by multiple regression or stepwise multiple regression using the underlying variables. A multivariate outlier test identified one observation as discordant, and removing that observation improved prediction further.