Ion exchange and Particle Size

[Cliff Mitchell]

I have been told that ion exchange chromatography does not benefit from using smaller particle sizes, at least not to the same extent that reverse phase separations does.

Is this true? Why?

Is this documented? Papers or books?

[Chris Pohl]

Cliff,

There is no truth to this rumor. Someone may have drawn the conclusion from the fact that there are fewer small particle ion exchange materials but this stems from the fact that the magnitude of available selectivity control is usually greater in ion exchange than in reversed phase so it's usually not necessary to resort to small particle sizes in order to achieve the necessary resolution when using ion exchange. Since small particle size usually brings with it ruggedness and reliability compromises, my first preference is to stay away from small particle sizes when designing new phases unless absolutely necessary.