Identifier

etd-07122006-141211

Degree

Master of Science in Chemical Engineering (MSChE)

Department

Chemical Engineering

Document Type

Thesis

Abstract

Polycyclic aromatic compounds (PAC) are organic compounds composed of two or more fused benzene rings. These compounds are ubiquitous in the environment and some are found to be mutagenic and carcinogenic. High rates of esophageal cancer in the Henan Province of China had led to the suspicion that PAC from domestic coal and wood combustion are the main cause. Extraction of PAC from wood soot was done with a Soxhlet apparatus using dichloromethane as the solvent and concentration of the solution using a Kuderna Danish apparatus. Analysis of the different PAC was performed by high performance liquid chromatography (HPLC) with diode-array ultraviolet-visible absorbance detection and by gas chromatography-mass spectrometry (GC/MS). HPLC retention time and UV absorbance spectral matches between sample components and reference standards present unequivocal identification of the PAC. Results showed that 84 compounds composed of oxygenated PAC, alkylated PAH, cyclopenta-fused PAH, and benzologues of pyrene, fluoranthene, and perylene were identified. There were a total of 35 compounds (3 oxygenated PAC, 5 methylated PAH and ethynyl-substituted PAH, 3 cyclopenta-fused PAH, and 24 benzologues of pyrene, fluoranthene, and perylene) that have never been reported before as products of wood combustion. Aromatic compounds detected in the GC/MS were 17 oxygenated, 14 methylated and ethynyl-substituted, and 8 nitrogen-substituted. Yields showed that 5- and 6-ring PAH dominate the wood soot extract. These groups represent the most carcinogenic and mutagenic PAH, specifically the C24H14 group, and comprise 66% of the total amount of PAH contained in the soot. The PAH with the highest yield are benzo[a]pyrene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene. The high yield and the large number of PAC present in the soot suggest that the PAC may be contributing factors in the high rate of esophageal cancer in Henan, China.

Date

2006

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Mary Julia Wornat

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