Background: Polybrominated diphenyl ethers (PBDEs) are additive flame retardants which are found in household and commercial products. These chemicals have the potential to leach from the product into the environment. Human health effects include neurodevelopmental changes, low birth weight and thyroid hormone changes have also been reported, although continued research in this field is needed. Humans are exposed to PBDEs through various exposure pathways and recent studies have determined that exposure to household dust is also a significant route of exposure for humans. The purpose of this study was to access the risk for PBDE intake through an exposure assessment. Also, a laboratory protocol for the fractionation and determination of PBDEs in household dust was developed and evaluated. Methods: PBDE concentrations in indoor dust were measured and compared to previously published data on the topic. A laboratory protocol for fractionation of indoor dust and determination of PBDEs in indoor dust was developed. The new laboratory method was compared to a previously published lab procedure to determine its effectiveness. A p-value of <0.01 and 95% confidence intervals were used to determine statistical significance. Intake estimates were also determined for adults and children exposed at different rates. Results: PBDEs were detected in all the house dust samples with total concentrations (sum of 12 congeners) ranging from 2,870 to 50,642 ng/g dry mass. The averaged concentrations from the six replicate sieve fractions ranged from 106 to 5,697 ng/g dry weight. Daily dust intake rates, based on previously published estimates, range from 20 to 200 mg/day for children and 0.56 to 50 mg/day for adults. Low and high estimates of the daily intake of PBDEs in children and adults were calculated using the average concentration of total PBDEs found in house dust in this study. The exposure estimates for children were approximately 371 to 3,709 ng PBDEs daily based on a mean value of 18,546 ng/g dry weight. The estimate for adults was approximately 10.4 to 927 ng/g dry weight. Conclusions: The new laboratory protocol produces comparable results for QA/QC materials compared to a previously published protocol. Particulate size does not appear to be a significant factor in PBDE concentration and future analysis may only need dust particles to be sieved to one or two sizes (i.e. 500 um and 125 um). Based on the potential intake calculations for children and adults, dust appears to be a significant route of exposure for PBDEs and analysis of additional dust samples will broaden the scope of available data for this method.

The study of excess thermodynamic properties of liquid mixtures is very important for designing the thermal separation processes, developing solution theory models and to have a better understanding of molecular structure and interactions involved in the fluid mixtures. In particular, heat of mixing or excess molar enthalpy data of binary and ternary fluid mixtures have great industrial and theoretical significance. In this connection, the experimental excess molar enthalpies for seventeen binary and nine ternary systems involving hydrocarbons, ethers and alcohol have been measured at 298.15K and atmospheric conditions for a wide range of composition by means of a flow microcalorimeter (LKB 10700-1). The binary experimental excess molar enthalpy values are correlated by means of the Redlich-Kister polynomial equations and the Liebermann - Fried solution theory model. The ternary excess molar enthalpy values are represented by means of the Tsao-Smith equation with an added ternary term and the Liebermann-Fried model was used to predict ternary excess molar enthalpy values. The Liebermann-Fried solution theory model was able to closely represent the experimental excess enthalpy data for most of the binary and ternary systems with reasonable accuracy. The correlated and predicted excess molar enthalpy data for the ternary systems are plotted in Roozeboom diagrams

This thesis investigates the use of arene chromium complexes as phenyl cation synthons in the synthesis of homochiral N-phenylamino esters, and the dianion formation of a series of complexed aryl ethers. Chapter 1 reviews the properties of arene chromium tricarbonyl complexes and discusses in detail the ability of some of these complexes to undergo nucleophilic aromatic substitution. Chapter 2 outlines the biological importance of homochiral N-phenylamino esters. The N-phenylation of a series of amino alcohols are first investigated both by direct reaction of haloarene complexes with amino alcohols and also via a Smiles rearrangement of an aryl ether derivative. In addition, methodology is developed for the synthesis of a series of homochiral N-phenyl-α-amino esters and N-phenyl-β-amino esters. The synthetic strategy is then applied to the synthesis of some N-phenyl-β-lactams, in particular (+)SCH 48461. Chapter 3 reviews the directed metallation of complexed and uncomplexed arene compounds and discusses the mechanism involved. The generation of dianions in a series of complexed aryl ethers is investigated. Regioselective deprotonation is observed using different alkyllithium bases and the degree of dianion formation is confirmed by electrophilic quench of the dianionic intermediates with CD₃OD and TMSC1.

No description available.

Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: John F. MacGregor. Includes bibliographical references (p. 138-152). Also available online.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2002. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Univ., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 6 uppsatser.

Thesis (M.S.)--Villanova University, 2008. / Chemistry Dept. Includes bibliographical references.

Thesis (M.S.)--Villanova University, 2008. / Chemistry Dept. Includes bibliographical references.