Linear isotherm determination from linear gradient elution experiments.

Area of Science:

• Chromatography
• Adsorption Science
• Chemical Engineering

Background:

• Analytical solutions for linear gradient elution chromatography often assume equal access of proteins and modifiers to porous particle pores.
• This assumption overlooks the size exclusion effect, where different molecules may access different pore fractions.

Purpose of the Study:

• To develop a procedure for estimating equilibrium adsorption parameters as a function of modifier concentration in linear gradient elution chromatography.
• To account for the size exclusion effect impacting protein and modifier access to pore sizes.

Main Methods:

• Derived a new analytical solution using perturbation theory for differential equations.
• Presented the 1st-order approximated solution to model the system.
• Validated the procedure by comparing with experimental data.

Main Results:

• The developed procedure reliably estimates isotherm parameters across varying modifier concentrations.
• The new analytical solution accurately models systems with differential size exclusion effects.
• The method provides a turnkey solution for analyzing linear gradient elution experiments.

Conclusions:

• The proposed procedure offers a reliable and efficient method for estimating adsorption parameters in chromatography.
• Accounting for size exclusion significantly improves the accuracy of models under linear gradient elution.
• This advancement facilitates better understanding and optimization of chromatographic separations.