Basic Structure-Independent Equations of Kinetic Performance of Columns in Liquid Chromatography

Area of Science:

• Analytical Chemistry
• Separation Science
• Chromatography

Background:

• The lowest dimensionless plate height (h_min) and flow resistance parameter (ϕ) are subjective and unsuitable for comparing kinetic performance across diverse liquid chromatography (LC) column structures.
• Existing metrics lack correlation with actual column performance for certain column types, such as monolithic and pillar-array columns.

Purpose of the Study:

• To introduce and validate objective, measurable replacements for subjective LC column performance metrics.
• To develop a framework for comparing the kinetic performance of differently structured LC columns.
• To establish structure-independent equations for LC column kinetic performance.

Main Methods:

• Introduction of measurable effective diameter and structural quality factor (q_max) as objective metrics.
• Development of basic equations linking LC column kinetic performance with q_max, operational conditions, and other parameters.
• Derivation of known and novel equations for column kinetic performance from the basic ones.

Main Results:

• Effective diameter and q_max are proposed as objective replacements for ϕ and h_min.
• The structural quality factor (q_max) is identified as a suitable metric for comparing differently structured LC columns.
• Structure-independent basic equations governing LC column kinetic performance were successfully developed.

Conclusions:

• Objective metrics like q_max provide a reliable basis for comparing LC column kinetic performance.
• The developed equations offer a unified approach to understanding and predicting column performance.
• The study provides a practical example of using these new metrics for column selection.