SummaryA single-step coating method for the preparation of glass capillary SCOT columns is described. It is reproducible and less time-consuming than the well-known two-step coating procedures. Other methods attempted are discussed briefly. Both the flame ionization and electron capture detectors could be used in conjunction with temperature programming. The separations achieved with an "activity mixture", phenols and phenolic acids, illustrate the resolution obtained. The columns are suitable for quantitative determinations and a comparison is made with a conventional packed column.