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Single-Molecule Tracking Microscopy - A Tool for Determining the Diffusive States of Cytosolic Molecules
Published on: September 5, 2019
Simultaneous determination of binary diffusion coefficients from multiple response curves by chromatographic
Toshitaka Funazukuri1, Chang Yi Kong, Seiichiro Kagei
1Department of Applied Chemistry, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan. funazo@chem.chuo-u.ac.jp
Journal of Chromatography. A
|September 30, 2006
Summary
This study accurately measured diffusion coefficients and retention factors for fatty acids in supercritical carbon dioxide using chromatographic impulse response. The method effectively analyzed mixtures, showing minimal component interaction effects.
Area of Science:
- Analytical Chemistry
- Physical Chemistry
- Chemical Engineering
Background:
- Supercritical fluids, particularly carbon dioxide, are valuable solvents in chemical analysis.
- Accurate determination of diffusion coefficients and retention factors is crucial for chromatographic method development.
- Analyzing mixtures presents challenges due to overlapping signals and potential component interactions.
Purpose of the Study:
- To apply the chromatographic impulse response technique for simultaneous measurement of binary diffusion coefficients (D) and retention factors (k).
- To determine these parameters for unsaturated fatty acids in supercritical carbon dioxide.
- To assess the accuracy and reliability of analyzing mixtures compared to single-component injections.
Main Methods:
- Utilized a polymer-coated capillary column with supercritical carbon dioxide as the mobile phase.
- Employed the chromatographic impulse response technique to inject a hexane solution of three unsaturated fatty acids.
- Applied curve fitting analysis to estimate D and k values, even with partially overlapping response curves (resolution of 0.8).
Main Results:
- Successfully obtained accurate infinite dilution binary diffusion coefficients (D) and retention factors (k) for alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid.
- Achieved accuracy comparable to single-component injection methods.
- Demonstrated minimal influence of inter-component interactions on the determined parameters, confirmed through various curve fitting approaches and sequential injections.
Conclusions:
- The chromatographic impulse response technique is effective for simultaneously determining diffusion coefficients and retention factors of multiple solutes in supercritical fluids.
- This method provides accurate results for mixture analysis, comparable to individual component analysis.
- Component interactions in the studied mixture did not significantly affect the obtained thermodynamic and transport properties.
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