Rational Method for Designing Efficient Chromatography Processes based on the Iso‐Resolution Curve

Abstract

A method for designing efficient chromatography processes was proposed and verified experimentally. The model samples were polyphenols. Polystyrene divinylbenzene resins were employed for the column stationary phase. The mobile phase was an ethanol-water mixture. The distribution coefficient, K, was determined as a function of ethanol concentration, I, by linear gradient elution experiments. The HETP-mobile phase velocity (u) curves were determined as a function of I. A method for calculating the iso-resolution curve was developed with K and HETP-u as a function of I. The calculated iso-resolution curve was verified by comparison with experimental elution curves. The iso-resolution curve was found to be useful for determining suitable separation conditions.

A simple method for calculating the productivity of polyphenol separations by polymer-based chromatography

“…The values of A, B and K c determined are as follows. 6) K c is the value where there is no adsorption (distribution due to size exclusion).…”

“…Catechin: A = 5.34 × 10 4 , B = 3.1, K c = 0.69 EGCG: A = 8.62 × 10 6 , B = 4.5, K c = 0.69 HETP vs. u plots for the two samples at different I values were well fitted by the following Van Deemter type equation. 6) HETP…”

“…4d p ) was used for the calculation. 6) The stationary phase diffusion coefficient D s values at different I values were correlated by Equation (6), which is derived from the pore diffusion coefficient D p based on the pore concentration C p considering the distribution between C p and C s .…”

“…Experimental data reported in our previous studies 5,6) were used in the calculation. Here we briefly describe materials and methods.…”

“…We have investigated the retention and the separation mechanism of polyphenols (catechin and epigallocatechin gallate, EGCG) by polystyrene divinylbenzene (PS-DVB) resin chromatography with the ethanolwater mixture mobile phase. 5,6) A method for predicting efficient separation conditions based on the model originally developed for linear gradient elution (LGE) ion-exchange chromatography of proteins 7,8) was successfully applied to this model separation system. It was also shown that a concept "iso-resolution curve", which was found to be useful for designing LGE separation of proteins, can be applicable.…”