Sol-gel-derived crown ether stationary phase for capillary gas chromatography

A new type of capillary gas chromatographic stationary phase containing OH-dibenzo-14-crown-4 (OH-DB14C4) was fabricated by the sol-gel process and coated onto the inner walls of a fused silica capillary. Multiple preparation steps in conventional column technology were avoided. The column demonstrates high column efficiency (>3000 plates m(-1)), outstanding thermal stability (to 330 degrees C) and a significant ability of deactivation. Compared with a sol-gel OH-terminated silicone oil (OH-TSO) column, the sol-gel OH-DB14C4 column has unique selectivity for the separation of positional isomers of aromatic compounds. In comparison with the dibenzo-propyl-15-crown-5 polysiloxane (PSO-DB-3-15C5) stationary phase, the sol-gel OH-DB14C4 has a high column capacity in separating small-molecular-mass compounds, such as low-molecular-mass alcohols, short-chain fatty acids, and volatile amines. The possible mechanism involved in sol-gel coating with OH-DB14C4 is discussed.