A method of forming a stationary phase of a capillary column for gas chromatography includes in situ growth of a metal-organic framework on an inner surface of the capillary column. The capillary column may include fused silica on an inner surface thereof and can be treated to provide functional groups capable of forming covalent bonds with a difunctional organic linker of the metal-organic framework. Epitaxial growth of the metal organic framework can occur directly on the inner surface of the capillary tube to a desired uniform thickness, controllable by concentration of metal organic framework precursors.