<p> Coal tar is a rich source of polycyclic aromatic compounds (PAC) which include
hydrocarbons (PAH), sulfur-containing aromatics (PASH), nitrogen-containing aromatics
and high molecular mass PAH. The separation of coal tar into four fractions was carried out
on activated (170°C, 48 hrs) neutral alumina. Low mass aromatics and aliphatics were
eluted with hexane in fraction A1 (2.2% recovery), while PAH/PASH were eluted by
benzene in fraction A2 (25%). High molecular mass PAH were eluted by dichloromethane
in fraction A3 (5.5%) and nitrogen-containing aromatics were eluted by methanol in fraction
A4 (21%). These fractions were characterized by normal phase liquid chromatography, GCMS, probe mass spectrometry (for fractions A3 and A4) and LC-MS (for fraction A3).</p> <p> While ratio of PASH to PAH in fraction A2 was rather unfavorable (25:1), the separation of PASH from PAH was attempted using two methods: an oxidation/reduction method and a ligand exchange method. The oxidation/reduction method of Lee was a complete failure. The PdCl2-silica method of Nishioka was partially successful. Of the 25 thia-arenes identified in fraction A2, 12 eluted with the PAH while the other 13 were either partially (5) or fully (8) retained by the PdCl2-silica gel column and then eluted later to give a sulfur-enriched fraction. This fraction was further separated using normal phase HPLC to afford sulfur-containing compounds with molecular masses between 184 amu and 258 amu which exhibited almost no contamination due to PAH. Thus, it would be possible to purify about one-half of the PASH from a complex mixture such as coal tar.</p> <p> Fraction A3 which contained high mass PAH was subjected to semi-preparative normal phase HPLC to afford several high molecular mass PAH fractions. The 326 amu PAH fraction was selected because it contributed to 10% of the genotoxic of the mixture. This fraction was further separated by normal phase HPLC and the subfractions were analyzed by reversed-phase HPLC with diode-array detection. Thirty-five peaks were collected from the reversed-phase HPLC analysis and were characterized by probe mass spectrometry and fluorescence spectroscopy (in part). Of the 35 peaks, 8 peaks were eluted in the mutagenic active range; these eight compounds will be evaluated using the Ames assay to determine which are active mutagens.</p> / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19419 |
| Date | January 1997 |
| Creators | Li, Chun-Ling |
| Contributors | McCarry, B. E., Chemistry |
| Source Sets | McMaster University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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