A capillary column (10) includes a tube structure having inner walls (14) and a sol-gel substrate (16) coated on a portion of inner walls (14) to form a stationary phase coating (18) on inner walls (14). The sol solution used to prepare the sol-gel substrate (16) has at least one baseline stabilizing reagent and at least one surface deactivation reagent resulting in the sol-gel substrate (16) having at least one baseline stabilizing reagent residual and at least one surface deactivating reagent residual. A method of making the sol-gel solution is by mixing suitable sol-gel precursors to form the solution, stabilizing the solution by adding at least one baseline stabilization reagent, deactivating the solution by adding at least one surface deactivation reagent to the solution, and reacting the solution in the presence of at least one catalyst.