During hydrophobic chromatography, which solvent is commonly used for elution?

In hydrophobic chromatography, the primary goal is to separate compounds based on their hydrophobic (water-repelling) characteristics. Typically, a chromatography medium is designed with hydrophobic regions that interact strongly with non-polar molecules. During the elution process, it is essential to disrupt these interactions to selectively release the bound proteins or compounds.

Acetonitrile is commonly used as an elution solvent in hydrophobic chromatography due to its relatively low polarity compared to water. It increases the solvent's ability to solvate more hydrophobic compounds, allowing them to elute from the stationary phase. The non-polar nature of acetonitrile helps decrease the interaction between the bound molecules and the stationary phase, facilitating their release.

In contrast, water, being polar, would not effectively elute non-polar compounds from the hydrophobic stationary phase, as it does not weaken the hydrophobic interactions. Ethyl acetate, while it is somewhat hydrophobic, does not provide the optimal elution strength that acetonitrile does in most cases. Acetic acid, although it has some hydrophobic character, is primarily a polar solvent and similarly would not serve as an effective eluent in this context. Thus, acetonitrile stands out as the preferred el