Hydrophobic interaction chromatography (HIC) separates peptides and proteins by surface hydrophobicity under native, non-denaturing conditions. In research peptide analysis, HIC is used in the laboratory to resolve variants that reversed-phase methods can denature or fail to distinguish, under controlled conditions only.

How the method works: The sample is loaded in a high-salt buffer, which promotes binding to a mildly hydrophobic stationary phase, and eluted with a decreasing salt gradient so less hydrophobic species leave the column first. Because binding happens in aqueous, near-physiological buffers, the method preserves native conformation, which makes it useful for studying folded states and for separating oxidized or otherwise subtly modified variants.

Applications and limits: HIC complements reversed-phase HPLC and ion exchange chromatography in orthogonal purity workflows, and findings are confirmed against HPLC purity and mass spectrometry identity on the lot-matched Certificate of Analysis. Resolution depends on salt type and concentration, temperature, and resin choice, so laboratories validate the method for each analyte and document conditions and lot numbers in their records.

Disclaimer: This article is for laboratory research purposes only. Not for human consumption. Not for medical, therapeutic, diagnostic, or veterinary use. No dosing, reconstitution-for-use, or efficacy information is provided or implied.

Citations: Standard HIC method literature on hydrophobic interaction separations and salting-out binding models; HPLC/MS peptide characterization methods.