Gas—liquid microcapillary columns precoated with graphitized carbon black

Glass and fused-silica capillary columns (100 μm I.D.) were precoated with a very thin layer of graphitized carbon black and then coated with polar liquid phases. The layer of graphitized carbon black and then coated with polar liquid phases. The layer of carbon black in the inner walls increased the wettability of the capillary columns and, consequently, a very uniform coating was obtained. The polymeric polar liquid phases were also more strongly retained on the carbon black, and these microcapillary columns showed a much higher temperature stability. Columns coated with free fatty acid phase, Carbowax 20M, 40M and 600M were prepared. The columns were tested with a mixture of polar compounds.