eprintid: 9340 rev_number: 4 userid: 6 dir: disk0/00/00/93/40 datestamp: 2011-11-10 20:01:52 lastmod: 2016-11-15 13:50:09 status_changed: 2011-11-10 20:01:52 type: thesis_degree metadata_visibility: show contact_email: zh.hong@gmail.com item_issues_count: 0 eprint_status: archive creators_name: Zhao, Hong creators_email: zh.hong@gmail.com title: PARTITIONING AND MOLECULAR RECOGNITION IN TEFLON AF / FC-72 AND DETERMINATION OF BARBITURATES WITH CAPILLARY ELECTROPHORESIS ispublished: unpub divisions: sch_as_chemistry full_text_status: public keywords: barbiturate; capillary electrophoresis; fluorous; MEKC; molecular recognition; Partition; polymer; stacking; Teflon AF abstract: The unique nature of fluorocarbon solvents makes them significant in selective extraction. We studied noncovalent intermolecular associations in fluorous media (fluorous solvents/polymers), and receptor enhanced-extraction of 3-hydroxypyridine with a fluorous solvent, FC-72, and a fluorous polymer, Teflon AF 2400. The association through hydrogen bonding and electrostatic interactions between fluorinated carboxylic acids and 3-hydroxypyridine improves the extraction of 3-hydroxypyridine into FC-72 and the films prepared from Teflon AF 2400. The association is found to be substantially stronger in FC-72 than in chloroform; however weaker in the fluorous films due to the specific properties of the polymer and sorption of solvents in the films. Dimensionally stable and chemically inert fluorous polymer films have advantages in fluorous separations. Films of Teflon AF 2400 were cast from solution. Transport measurements on a series of solutes with different polarity and functional groups reveal that the selectivity of the films with and without a perfluoropolyether plasticizer. The films favor the transport of fluorinated solutes in comparison to the hydrogen-containing control. Transport rates are dependent on the solvent making up the source and receiving phases. Various solvents, including organic solvents and the nonvolatile perfluoropolyether plasticizer, were investigated and compared.To study the selectivity of extraction and membrane transport, an important part of the work is analysis of mixtures of solutes. Capillary electrophoresis (CE) is a powerful analytical technique for separation of diverse samples. For increased sensitivity in CE, we investigated the optimal stacking conditions for separation of barbiturates and analogs with capillary zone electrophoresis (CZE), and micellar electrokinetic chromatography (MEKC). To achieve stacking for all the analytes that have a wide distribution of affinity for the SDS micelles in MEKC, high pH sample matrices have been used to ionize the analytes, thus decreasing their affinity for the SDS micelles, and resulting stacking similar as that in CZE. Both normal stacking and transient ITP stacking mechanism are involved, depending on the sample matrix. date: 2006-03-30 date_type: completed institution: University of Pittsburgh refereed: TRUE etdcommittee_type: committee_chair etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_name: Weber, Stephen etdcommittee_name: Michael, Adrian etdcommittee_name: Curran, Dennis etdcommittee_name: Beckman, Eric etdcommittee_email: Sweber@pitt.edu etdcommittee_email: amichael@pitt.edu etdcommittee_email: curran@pitt.edu etdcommittee_email: beckman@engr.pitt.edu etdcommittee_id: SWEBER etdcommittee_id: AMICHAEL etdcommittee_id: CURRAN etdcommittee_id: BECKMAN etd_defense_date: 2005-08-22 etd_approval_date: 2006-03-30 etd_submission_date: 2005-09-08 etd_access_restriction: immediate etd_patent_pending: FALSE assigned_doi: doi:10.5195/pitt.etd.2011.9340 thesis_type: dissertation degree: PhD committee: Prof. Stephen Weber (Sweber@pitt.edu) - Committee Chair committee: Prof. Adrian Michael (amichael@pitt.edu) - Committee Member committee: Prof. Dennis Curran (curran@pitt.edu) - Committee Member committee: Prof. Eric Beckman (beckman@engr.pitt.edu) - Committee Member etdurn: etd-09082005-144715 other_id: http://etd.library.pitt.edu/ETD/available/etd-09082005-144715/ other_id: etd-09082005-144715 citation: Zhao, Hong (2006) PARTITIONING AND MOLECULAR RECOGNITION IN TEFLON AF / FC-72 AND DETERMINATION OF BARBITURATES WITH CAPILLARY ELECTROPHORESIS. Doctoral Dissertation, University of Pittsburgh. (Unpublished) document_url: http://d-scholarship-dev.library.pitt.edu/9340/1/Hong.Zhao_PhD_Dissertation_12132005.pdf