Chen, Zhi
(2006)
Molecular Recognition in Plasticized Poly(vinyl chloride).
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
Mixtures of poly(vinyl chloride) (PVC) with plasticizers have been used in ion-selective electrodes for many years. The same material has proven useful in solid-phase microextraction (SPME), both with and without artificial receptors. In the first study, we hypothesized that by increasing the polymer concentration in plasticized PVC membranes containing artificial receptor, the extraction selectivity of target barbiturates over similar molecules could be improved. This is verified by SPME-CE experiments. At 30%, 40%, and 50% (w/w) PVC, as polymer concentration increases, selectivity for barbiturate extraction over other cyclic imides becomes better in the presence of barbiturate receptor and worse without it. In the second study, SPME has been applied to the analysis of eight barbiturate drugs and drug analogs in serum samples. Finally, a screening method for fast evaluation of chiral selectors has been proposed based on molecular recognition in plasticized PVC membrane. The advantage of this method is that it does not require the covalent immobilization of either the analyte or the selector, and the potential selector usage is at the microgram level. The method needs to be verified prior to application to libraries of peptide mimics. R/S-N-(3,5-dinitrobenzoyl)-phenylglycine bonded to silica gel is a commercial available brush-type CSP which can resolve various racemic mixtures, such as Troger's base, 2,2,2-trifluoro-1-(9-anthryl)-1-ethanol, 1-phenyl-butanol, etc. We have used freely diffusing selectors (R or S-N-(3,5-dinitrobenzoyl)-phenylglycine and its methyl ester). The selectors are doped into plasticized PVC membranes. The test analytes are the three mentioned above. Distribution difference of the two enantiomers of the Troger's base and 1-phenyl-butanol could be detected by the extraction of plasticized PVC membrane containing the test chiral selector. The difference in the selectivities is significant (p<0.01) by a t-test. Thus, we have demonstrated that a partitioning experiment with a selector-doped membrane can be used to determine the efficacy of a potential chiral selector.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
29 June 2006 |
| Date Type: |
Completion |
| Defense Date: |
17 August 2004 |
| Approval Date: |
29 June 2006 |
| Submission Date: |
24 April 2006 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Chemistry |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
CE; CSPs; high-throughtput screening |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-04242006-140317/, etd-04242006-140317 |
| Date Deposited: |
10 Nov 2011 19:41 |
| Last Modified: |
15 Nov 2016 13:42 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/7588 |
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