Thin-Layer Graphited Carbon Black as the Stationary Phase for Capillary Columns in Gas Chromatography

GOLAY pointed out in his early papers1,2 that excellent capillary columns could be produced by replacing the smooth inner wall area of a tubular column by a uniform porous layer of the support material. Petitjean et al.3 and Mohnke et al.4 were the first to use adsorption-type tubular columns. Both of them invented special methods for preparing alumina and silica adsorption layers from the materials of the walls by chemical reactions. The following general method can presumably be used for depositing any solid substance on the walls of open tubular columns. Here we report our results using carbon black graphited at 3,000° C (surface area 72.8 m2/g)5. 15 g of this carbon black was suspended by rapid stirring in a mixture of 220 ml. trifluortrichlor-ethane and 30 ml. carbon tetrachloride. The carefully cleaned copper tube (in Fig. 2 silvered copper) was filled with this suspension. One end of the tube was closed and the open end was fed cautiously and slowly in a special oven to evaporate the liquid. After this procedure the carbon black remains on the wall of the column in the form of an adherent porous thin layer.