Which type of solvent would best elute a compound stuck on a column?

To effectively elute a compound that is stuck on a column, utilizing a more polar solvent is the optimal choice. This approach is grounded in the principles of polarity and the interactions between the stationary phase of the column and the compounds being separated.

In chromatography, compounds are separated based on their affinity for the stationary phase versus the mobile phase. If a compound is not moving effectively, it is likely interacting strongly with the stationary phase, which could be polar. Introducing a more polar solvent increases the likelihood of stronger interactions between the solvent and the compound, thereby disrupting the interactions holding the compound to the stationary phase. This increased polarity allows the compound to dissolve more readily in the solvent, facilitating its movement through the column.

For context, non-polar solvents may not be effective in displacing polar compounds as they cannot engage in strong interactions with them. Saturated solvents could lead to precipitation or poor solvation, which would not assist in eluting the compound. High-boiling solvents, while they have their uses in specific contexts, do not inherently enhance polarity and therefore may not aid in the elution process as effectively as a more polar solvent would.

Thus, employing a more polar solvent maximizes the chances of successfully eluting a compound that has become stuck,