At-column dilution for improved loading in preparative chromatography

Maximizing column loadability is an important part of preparative chromatography, since both the cost of the equipment and the cost of the operation increase with the size of the column. We have studied the parameters that determine column loadability. In this publication, we describe the influence that the choice of the sample solvent and the nature of the sample have on loadability. If the sample is injected onto the column in the classical way, overload effects result from the choice of conditions that favor a high solubility of the sample. We then demonstrate how a sample introduction technique called at-column dilution circumvents the difficulties associated with the limited solubility of samples under the preferred conditions of preparative chromatography The technique is discussed in detail.