wall-coated open-tubular (WCOT) column

in chromatography
https://doi.org/10.1351/goldbook.W06654
A column in which the liquid stationary phase is coated on the essentially unmodified smooth inner wall of the tube.
Source:
PAC, 1993, 65, 819. (Nomenclature for chromatography (IUPAC Recommendations 1993)) on page 831 [Terms] [Paper]