What technique separates ions and polar molecules based on their affinity to an ion exchanger?

The technique that separates ions and polar molecules based on their affinity to an ion exchanger is ion exchange chromatography. This method utilizes a resin or a polymer that contains charged groups, allowing for the selective adsorption of ions from a solution. The process works by exploiting differences in the charge properties of the molecules being separated.

In ion exchange chromatography, the sample containing a mixture of ions is passed through a column containing the ion exchange resin. Depending on their charge, different ions will interact with the resin to varying degrees, either binding to it or being displaced by other ions in the solution. As the elapsed time in the column varies for different ions, separation occurs, allowing for the collection of specific ions at different times.

This technique is particularly useful for purifying proteins, peptides, and nucleic acids, as well as for various analysis applications in biochemistry and molecular biology. The effectiveness of ion exchange chromatography lies in the strength of the interactions between the ions and the oppositely charged groups on the resin, which can be tuned through adjustments in pH and ionic strength of the mobile phase, enhancing resolution and selectivity in the separation process.