retention volume

Retention refers to the act or state of being retained, or the capacity to retain things, particularly in memory. In chromatography, retention describes how strongly a substance is attracted to the stationary phase versus the mobile phase. This attraction determines the rate at which substances migrate through a system.12

In elution chromatography, retention time is the duration for a solute to move through a column, measured from sample injection to peak maximum. Retention volume is calculated by multiplying retention time by the mobile phase's flow rate, providing a measure independent of flow rate variations. In gas chromatography, retention is often discussed in terms of relative retention volumes or retention index (RI), which helps classify stationary phases based on polarity and intermolecular interactions.34