Michael L. Taylor

Sources and fate of polychlorinated dibenzodioxins, dibenzofurans and related compounds in human environments

Several of the major incidents resulting in potential human exposures to polychlorinated dibenzodioxins (PCDDs) and/or polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and related compounds which have occurred in the U.S. in recent periods have resulted from improper disposal of hazardous chemical wastes. Prominent examples of such environmental contamination episodes are the Love Canal, into which ton quantities of chlorinated organic compounds containing substantial concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were deposited; numerous sites in the State of Missouri which were contaminated by the dumping of chlorinated organic wastes containing various PCDDs and possibly PCDFs, and PCBs; and the environs of a 2,4-D/2,4,5-T manufacturing plant site in Arkansas, which were contaminated with PCDDs. Environmental assessments of such sites have revealed extensive contamination of soils, waterways, fish and other biological species with these toxic compounds, which in turn could lead to human exposures. Other recently identified sources of PCDDs, PCDFs and related compounds in human environments include stack effluents from municipal refuse incineration, and fires and explosions involving electrical devices containing PCBs and polychlorinated benzenes. Data obtained in assessments of such incidents are presented, and the implications of these findings with respect to the distribution and persistence of PCDDs, PCDFs and related chemicals in the environment and possible effects on humans are discussed.

Identification of Thermal Degradation Products of Titanium Polyethers Using Coupled Thermogravimetric Analysis-Mass Spectroscopy: Development and Evaluation of Instrumentation

Abstract The construction and evaluation of a coupled Thermogravimetric Analyzer-Mass Spectrometer (TG-MS) instrument, capable of heating samples as small as one milligram to temperatures as high as 1200°C, while continuously monitoring the gaseous effluents using mass spectrometry, is described. Degradation of titanium polyethers was studied to assess the performance of the TG-MS.

Assessments of ambient air sampling techniques for collecting airborne polyhalogenated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and biphenyls (PCB)

Abstract An ambient air sampler employing a filter and a polyurethane foam/XAD-2 cartridge effectively traps and retains the 2,3,7,8-chlorine substituted dibenzo-p-dioxin and dibenzofuran isomers, as well as 2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD) and 2,3,7,8-tetrabromodibenzofuran (TBDF), and permits quantitation of these isomers in ambient air at concentrations lower than 1 pg/m 3 .

Results of comparative evaluations of various fused silica capillary GC columns for retention of tetrachlorinated dibenzo-p-dioxins and dibenzofurans

Abstract Absolute retention times for all twenty-two tetrachlorinated dibenzo-p-dioxin isomers and all thirty-eight tetra-chlorinated dibenzofuran isomers have been measured for several fused silica capillary GC columns coated with a variety of commercially available stationary phases. Data are reported for columns coated with 50% Cyano-propyl, 25% Phenylmethyl silicone (DB-225), 50% Trifluro-propylsilicone (SP-2401), and Polyethyleneglycol (DB-WAX). A two phase loading column for separation of 2,3,7,8-TCDF is presented.

Improved separations procedures for isolating 2,3,7,8-TCDD and 2,3,7,8-TCDF from chemically-complex aqueous and solid sample martrices and for definitive quantitation of these isomers at ppq to ppt concentrations

Abstract An analytical procedure has been developed and validated for quantitatively measuring 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-tetrachlorodibenzofuran (TCDF) present at parts-per-trillion (ppt) to parts-per-quadrillion (ppq) concentrations in various paper manufacturing process and waste water samples.

Characterization of toxic components in the effluents from a refuse-fired incinerator☆

Abstract Samples of stack effluents collected during July and August 1979 from a RDF-fueled incinerator have been analyzed for chlorodibenzo-p-dioxins (CDDs) and chlorodibenzofurans (CDFs). Using ultrasensitive, highly specific analytical methodology developed in this laboratory, CDDs, in particular, tetra-chlorodi-benzo-p-dioxins (TCDDs), and CDFs were readily quantitated in extracts of the effluent samples. More elaborate analyses were accomplished in order to determine the concentrations of individual TCDD isomers in the samples. Most, if not all, of the 22 TCDD isomers are apparently present in the stack effluents, but 1,3,6,8-TCDD appears to be the major isomer constitutent.

Sorption of Lubricant Additives by Porous Plastic Retainer Materials

Sorption of additives present in lubricating oils by porous plastic retainer materials was studied by liquid chromatographic experiments. Liquid chromatography columns were packed with finely shredded porous cotton-phenolic and polyimide ball bearing retainer materials. Small aliquots of nonpolar hydrocarbon oils (purified by molecular distillation and prepared to contain additives of various polarities) were individually eluted through, the columns with n-hexane. The eluate from each of the columns was evaporated, and the residues were analyzed for additive content. Atomic absorption and computer-controlled electron-impact mass spectrometry of the eluted samples provided evidence of retention of the lubricant additives in the column. The degree of depletion of additives from the oil samples appears to be a function of the polarities of both the retainer matrix and the additive molecules, and the hydrogen bonding or dipole-dipole interaction resulting therefrom. Presented at the 33rd Annual Meeting in Dea...

Structural Characterization of the Condensation Polymer of Dipyridine Manganese II Dichloride with 1,3-Di-4-piperidy I propane

Abstract The synthesis of polymers derived from the condensation of dipyridine manganese II dichloride with 1,3-di-4-piperidylpro-pane is described. Structural analysis of the polyamines is detailed utilizing results based on infrared, thermal, elemental and solution analyses.