R.K. Mitchum

Analysis of municipal incinerator fly ash for bromo- and bromochloro-dioxins, dibenzofurans, and related compounds

Abstract An intensive investigation was made of the organic components of a representative fly ash sample from a municipal incinerator. The sample was analyzed using U.S. EPA RCRA Method 8280 incorporating both low and high resolution mass spectrometric techniques. Brominated and bromochlorinated analogs of polycyclic aromatic hydrocarbons as well as bromochlorinated dibenzodioxins and dibenzofurans were detected in this municipal incinerator fly ash sample.

Electrophilic bromination of dibenzo-p-dioxin

Abstract Dibenzo- p -dioxin has been brominated under standard electrophilic conditions to yield mono- through octabromodibenzodioxin. The GC retention indices (RI) for thirteen products have been measured and correlated with the retention indices calculated for the corresponding chlorodibenzodioxins. Mass spectra for the eight major congeners are reported. Brominated dibenzodioxins (PBDDs) may be widely dispersed in the environment, arising from oxidative ring closure of fire retardant brominated diphenyl ethers, combustion of other bromine containing materials, from the use of brominated phenols as synthetic intermediates, and other routes analogous to the formation of the polychlorinated dibenzodioxins (PCDDs). In order to monitor possible environmental contamination by highly toxic PBDDs, authentic analytical chemical standards of these compounds must be available. We wish to report the synthesis of certain congeners of mono-through octa-PBDDs, mass spectral characteristics and retention indices for these compounds. The retention indices for these compounds were found to correlate well with the calculated and observed values of the PCDDs. We have recently developed a model which correlates retention index with structure and provides a simple method to calculate the RI for the PCDDs. This correlation was used to assist in assigning structures while minimizing potential human exposure to these materials.

Electrophilic bromination of dibenzofuran

Abstract Dibenzofuran has been brominated under standard electrophilic conditions to yield mono- through octabromodibenzofuran. The GC retention indices for ten products have been measured and correlated with the retention indices for the corresponding chloro dibenzofurans. Mass spectra for the eight major products are reported.

Method 8290: an analytical protocol for the multimedia characterization of polychlorinated dibenzodioxins and dibenzofurans by high-resolution gas chromatography/high-resolution mass spectrometry

Abstract The principal features of a new analytical protocol for the determination of polychlorinated dibenzo-p-dioxins and dibenzofurans by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) are presented and discussed.

Preparation of bromochlorodibenzo-p-dioxins and dibenzofurans and analysis by EPA RCRA method 8280

Abstract Dioxin and dibenzofuran standards containing both bromine and chlorine substituents have been prepared. Standard mixtures have been spiked into an artificial soil matrix and successfully analyzed by the EPA-RCRA Method 8280. Criteria are proposed for confirming their presence in environmental samples.

Synthesis of polyhalogenated dibenzo-p-dioxins

Abstract Bromochlorophenols have been prepared by catalytic bromination of commercially available chlorophenols. The corresponding bromochloro potassium phenolates have been condensed under Ullmann conditions to yield bromochlorodibenzo- p -dioxins. Products are assigned structures based upon the structure of the starting phenol, mass spectrometry, statistical analysis of the reaction pathways and GC retention time.

HRGC/HRMS analysis of hazardous waste incinerator scrubber water for PCDDs and PCDFs

Abstract A multi-laboratory study was conducted using the U.S. EPA HRGC/HRMS Method 8290 to establish realistic method detection and practical quantification limits for 2,3,7,8-substituted polychlorodibenzo-p-dioxins (PCDDs) and 2,3,7,8-substituted polychlorodibenzofurans (PCDFs) in hazardous waste incinerator scrubber water. The data were required by the U.S. Environmental Protection Agency to establish guidelines for the disposal of PCDD- and PCDF-contaminated scrubber water.

Environmental levels and fate of dioxins and furans

Abstract Biological and environmental levels of PCDDs and PCDFs are used to make risk estimates, correlate exposure with clinical observations, and determine the fate of these compounds in ecosystems. The many measurement activities reported here, although unrelated, serve to define the use of biological and environmental data for accessing risk to both the exposed human population as well as the impacted ecosystems.