A comparison was made between NIOSH-type, prepacked nutshell charcoal tubes and layers of commercial charcoal cloth in a stainless steel cassette designed for the active sampling/adsorption of different concentrations of a mixture of volatile organic chemicals (VOCs) (benzene, trichloroethylene, toluene, tetrachloroethylene, chlorobenzene and o-xylene). Physicochemical parameters of the charcoal cloth including breakthrough times and volumes and adsorption capacities were determined for toluene and the VOC mixture. The quantitative removal of VOCs from the charcoal cloth by solvent desorption, by supercritical fluid extraction (SFE), and by thermal desorption was studied prior to analysis by gas liquid chromatography with photoionization detection. Optimal conditions were explored both in laboratory and industrial environments. / Charcoal cloth was comparable to the NIOSH tube, adsorbed VOCs being quantitatively removed at any time up to 32 days after sampling. Although solvent (pentane, hexane) desorption yielded accurate, reproducible results with a high percent recovery of the VOCs, a major disadvantage was the irreparable damage done to the cloth, preventing its repeated use. Desorption by SFE proved unreliable for these low molecular weight VOCs, both the collecting solvents and the VOCs being lost during extraction. Thermal desorption proved to be efficient, sensitive and reliable, repeated heating having no effect on the adsorptive properties of the cloth. Charcoal cloth would appear to be a useful adsorbing medium for air sampling of both industrial and office building/home environments for either single chemicals or mixtures.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41640 |
| Date | January 1993 |
| Creators | Kongtip, Pornpimol |
| Contributors | Ecobichon, D. J. (advisor), Farant, J. P. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Occupational Health.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001397563, proquestno: NN94647, Theses scanned by UMI/ProQuest. |
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