The obstruction factor in size-exclusion chromatography. 1. The intraparticle obstruction factor

Area of Science:

• Chromatography
• Polymer Science
• Physical Chemistry

Background:

• The obstruction factor (γ) is crucial in chromatography, influencing band broadening.
• Size-exclusion chromatography (SEC) is a valuable technique for polymer analysis.
• Understanding factors affecting γ(p) is essential for accurate chromatographic separations.

Purpose of the Study:

• To investigate the dependence of the intraparticle obstruction factor (γ(p)) on various parameters in SEC.
• To determine how analyte properties and column characteristics influence γ(p).
• To assess the impact of temperature on γ(p).

Main Methods:

• Utilizing narrow dispersity polymer standards for experiments.
• Systematically varying analyte molar mass, solvent, and column parameters (pore size, particle size).
• Conducting experiments within a limited temperature range.

Main Results:

• The intraparticle obstruction factor (γ(p)) is not constant and varies significantly with analyte molar mass and solvent.
• Column characteristics, including pore size and particle size, also impact γ(p).
• No statistically significant temperature dependence of γ(p) was observed within the tested range.

Conclusions:

• The obstruction factor (γ(p)) in SEC is a complex parameter influenced by multiple factors.
• These findings have implications for optimizing separations in SEC and other packed column chromatography techniques.
• SEC serves as a reliable method for quantifying the obstruction factor due to its minimal confounding factors.