The proposed work aims to establish a foundation for predicting partitioning and selectivities of solute molecules within chain molecule """"""""interphases"""""""", including the bonded stationary phases of reversed-phase liquid chromatography, and amphiphilic aggregates, such as monolayers, bilayers, vesicles, liposomes, and micelles. This work represents a continuing collaboration of a group at the University of Florida with a group at UCSF, combining theory and experiment. We have developed statistical mechanical theory for solute uptake which is supported by neutron scattering experiments of solute distribution in bilayers, retention vs. co- solvent composition in RPLC, and spectroscopic results on micelles. Our experiments in bilayers confirm the predicted expulsion of solute with surface denisty, due to configurational entropy. We have developed new methods for synthesizing bonded phases of varying surface density, and have shown partitioning to be a function of surface density. Preliminary theory further suggests molecular selectivity will increase with surface density. We have studied effects of interphase structure on retention. Here we aim to study effects of solute structure on retention. Solutes will include chains, rods, and disks; we expect that the high selectivities among molecules result from packing in the interphase. We also plan to study long chain solutes, homopolymers and heteropolymers, vs. chain length, composition, and temperature.
We aim to develop a molecular framework to understand how molecules partition into semi-ordered phases of chain molecules, including: (i) the molecular mechanisms of retention and selectivity in RPC, (ii) the fundamental physical chemistry of membranes and micelles. This should have broad implications for optimization in chromatography of small molecules and proteins; insertion of drugs, metabolites and proteins into membranes; adsorption of proteins at polymeric surfaces, and thus bear on fundamental issues of separations and biomedical sciences.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM033382-04
Application #
3283055
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1984-12-01
Project End
1990-11-30
Budget Start
1988-03-01
Budget End
1988-11-30
Support Year
4
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Florida
Department
Type
Schools of Arts and Sciences
DUNS #
073130411
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Cole, L A; Dorsey, J G; Dill, K A (1992) Temperature dependence of retention in reversed-phase liquid chromatography. 2. Mobile-phase considerations. Anal Chem 64:1324-7
Cole, L A; Dorsey, J G (1992) Temperature dependence of retention in reversed-phase liquid chromatography. 1. Stationary-phase considerations. Anal Chem 64:1317-23
Cole, L A; Dorsey, J G (1990) Reduction of reequilibration time following gradient elution reversed-phase liquid chromatography. Anal Chem 62:16-21
Michels, J J; Dorsey, J G (1990) Estimation of the reversed-phase liquid chromatographic lipophilicity parameter log k'w using ET-30 solvatochromism. J Chromatogr 499:435-51
Sentell, K B; Dorsey, J G (1989) Retention mechanisms in reversed-phase chromatography. Stationary phase bonding density and solute selectivity. J Chromatogr 461:193-207
Ying, P T; Dorsey, J G; Dill, K A (1989) Retention mechanisms of reversed-phase liquid chromatography: determination of solute-solvent interaction free energies. Anal Chem 61:2540-6
Sentell, K B; Dorsey, J G (1989) Retention mechanisms in reversed-phase liquid chromatography. Stationary-phase bonding density and partitioning. Anal Chem 61:930-4
Sentell, K B; Barnes, K W; Dorsey, J G (1988) Ultrasound driven synthesis of reversed-phase stationary phases for liquid chromatography using 4-dimethyl-aminopyridine as acid-acceptor. J Chromatogr 455:95-104
Michels, J J; Dorsey, J G (1988) Retention in reversed-phase liquid chromatography: solvatochromic investigation of homologous alcohol-water binary mobile phases. J Chromatogr 457:85-98
Johnson, B P; Khaledi, M G; Dorsey, J G (1987) Solvatochromic solvent polarity measurements and selectivity in reversed-phase liquid chromatography. J Chromatogr 384:221-30

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