Column packings thermal treatment

Surface silylation of solid supports, glass columns, inserts, or even glass-wool spacers and glassware for the sake of surface deactivation remains highly recommended in biochemical GC. An alternative approach to surface deactivation is the method of Aue et al. [93], in which thermal treatment of polymer-coated supports results in a partial linkage of the macromolecule to the surface. This approach has been successfully employed with both packed and capillary columns. 

A possible explanation of the results obtained with our procedure is that the water in the water-saturated SE-52 solution may be required for hydrolysis of the silicone polymer, and the breakdown products so produced, effectively silanize the Chromosorb G at 370°. It is also possible that a similar process may account for the silicone polymer treatment of the oxidized steel column. Here again, a thermal breakdown product of SE-52 may react with the metal oxide on the inner surface of the metal column to produce a layer which is less polar than the oxide itself. This might then lead to less adsorption and/or less destruction of the compounds being analyzed. Such a reaction might also account for the improvement in peak shape when stainless steel columns are heated in air prior to packing. The oxide or partial oxide so formed may facilitate subsequent reaction with the thermal decomposition product of the silicone polymer. It is important to note, however, that this thermal breakdown product must be formed in the absence of free oxygen. 

In thermal process engineering, packed columns as well as tray columns are often used for heat and mass transfer processes in rectification, absorption and extraction as well as for the cooling of gases and liquids and wastewater and groundwater treatment. They are mainly used for counter-current gas/liquid flow. Figure 1-1 shows the schematic structure of a packed column with random packing elements. 

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