Final answer:
Water may not be used as an eluent in chromatography because it lacks sufficient affinity to the hydrophobic stationary phase and does not effectively elute hydrophobic solutes, leading to issues like short retention times for certain compounds.
Step-by-step explanation:
Aside from its polarity, water might not be used to elute a column in chromatography due to a lack of affinity to the hydrophobic stationary phase relative to the mobile phase. Water can cause issues with compounds that have low octanol-water partition coefficients or are common metabolites, leading to short or non-existent retention times. Additionally, water is not suitable for use with certain reverse phase High Performance Liquid Chromatography (HPLC) techniques, where the stationary phase consists of silica particles coated with hydrophobic alkane chains. In these systems, solutes with higher hydrophobicity have stronger interactions with the stationary phase, which is not compatible with the use of water as an eluent.