{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/91013"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/91013","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Evaluation of a micro-adsorption detector in liquid and gas chromatography","abstract":"A study was made with the objectives: 1. Evaluation of a micro-adsorption detector for use in liquid chromatography. 2. Evaluation of a micro-adsorption detector for use in gas ch.ranatography. 3. Investigation of the micro-adsorption cell as a tool for screening chromatographic systems, in adsorption studies, and as a micro-calorimeter. The micro-adsorption detector was found to have sufficient sensitivity to detect nanogram quantities of a component in either a liquid or gaseous carrier, and to have a linear dynamic range of 10²-10³. These qualities, combined with the selectivity of the detector indicate its usefulness in both liquid and gas chromatographic operations. The major limitation to its use is the characteristic adsorption/desorption responsive curve, which requires increased column lengths or resolution over other detectors such as the UV detector. In addition a semi-quantitative correlation between MAD response and chromatographic retention times indicates that the detector has significant potential as a screening tool for separation systems. By means of a calibration apparatus the detector response was characterized in terms of heat flux and temperature differential, and heats of absorption were calculated at concentrations of 10⁻⁴- 10⁻⁶ molar. These compared favorably with those literature values which were available close to these concentrations.","abstract_html":"A study was made with the objectives: 1. Evaluation of a micro-adsorption detector for use in liquid chromatography. 2. Evaluation of a micro-adsorption detector for use in gas ch.ranatography. 3. Investigation of the micro-adsorption cell as a tool for screening chromatographic systems, in adsorption studies, and as a micro-calorimeter. The micro-adsorption detector was found to have sufficient sensitivity to detect nanogram quantities of a component in either a liquid or gaseous carrier, and to have a linear dynamic range of 10²-10³. These qualities, combined with the selectivity of the detector indicate its usefulness in both liquid and gas chromatographic operations. The major limitation to its use is the characteristic adsorption/desorption responsive curve, which requires increased column lengths or resolution over other detectors such as the UV detector. In addition a semi-quantitative correlation between MAD response and chromatographic retention times indicates that the detector has significant potential as a screening tool for separation systems. By means of a calibration apparatus the detector response was characterized in terms of heat flux and temperature differential, and heats of absorption were calculated at concentrations of 10⁻⁴- 10⁻⁶ molar. These compared favorably with those literature values which were available close to these concentrations.","abstract_has_math":false,"creators":["Stafford, David Todd"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Ph. 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Investigation of the micro-adsorption cell as a tool for screening chromatographic systems, in adsorption studies, and as a micro-calorimeter. The micro-adsorption detector was found to have sufficient sensitivity to detect nanogram quantities of a component in either a liquid or gaseous carrier, and to have a linear dynamic range of 10²-10³. These qualities, combined with the selectivity of the detector indicate its usefulness in both liquid and gas chromatographic operations. The major limitation to its use is the characteristic adsorption/desorption responsive curve, which requires increased column lengths or resolution over other detectors such as the UV detector. In addition a semi-quantitative correlation between MAD response and chromatographic retention times indicates that the detector has significant potential as a screening tool for separation systems. By means of a calibration apparatus the detector response was characterized in terms of heat flux and temperature differential, and heats of absorption were calculated at concentrations of 10⁻⁴- 10⁻⁶ molar. These compared favorably with those literature values which were available close to these concentrations."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Evaluation of a micro-adsorption detector in liquid and gas chromatography"]}]}],"canonical_facts":{"dc:contributor.department":["Chemistry"],"dc:creator":["Stafford, David Todd"],"dc:date.accessioned":["2019-07-03T18:08:53Z"],"dc:date.available":["2019-07-03T18:08:53Z"],"dc:date.issued":["1971"],"dc:description.abstract":["A study was made with the objectives: 1. Evaluation of a micro-adsorption detector for use in liquid chromatography. 2. Evaluation of a micro-adsorption detector for use in gas ch.ranatography. 3. Investigation of the micro-adsorption cell as a tool for screening chromatographic systems, in adsorption studies, and as a micro-calorimeter. The micro-adsorption detector was found to have sufficient sensitivity to detect nanogram quantities of a component in either a liquid or gaseous carrier, and to have a linear dynamic range of 10²-10³. These qualities, combined with the selectivity of the detector indicate its usefulness in both liquid and gas chromatographic operations. The major limitation to its use is the characteristic adsorption/desorption responsive curve, which requires increased column lengths or resolution over other detectors such as the UV detector. In addition a semi-quantitative correlation between MAD response and chromatographic retention times indicates that the detector has significant potential as a screening tool for separation systems. By means of a calibration apparatus the detector response was characterized in terms of heat flux and temperature differential, and heats of absorption were calculated at concentrations of 10⁻⁴- 10⁻⁶ molar. These compared favorably with those literature values which were available close to these concentrations."],"dc:description.degree":["Ph. D."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/91013"],"dc:language.iso":["en"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Evaluation of a micro-adsorption detector in liquid and gas chromatography"],"dc:type":["Dissertation"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. 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