Column heating, high-speed

When a high-speed agitator is used to disperse the gas for a reaction, the interfacial area per unit volume and the mass transfer coefficient are usually much larger than for a bubble column. The more vigorous agitation also leads to better heat transfer to a cooling coil or jacket and more uniform suspension of any solids that are present. The main disadvantages of the... 

The use of ultra-high-pressure regimes and/or flow rates in the micro- or nanoliters per minute range imposes unique requirements on LC system hardware, such as pumps, valves, injectors, connecting tubing, column construction, stationary phases, column heating systems, detection flow cells, and the detector s data collecting speed. 

Bicchi, C., C. Brunelli, C. Cordero, P. Rubiolo, M. Galli, and A. Sironi, 2005. High-speed gas chromatography with direct resistively-heated column (ultra fast module-GC) -separation measure (5) and other chromatographic parameters under different analysis conditions for samples of different complexities and volatilities, 1071 3. 

Recently, a method was proposed for preparing a capillary column with a silica layer based on the hydrothermal treatment of silica sol inside the column [110]. According to this method, the cetpillary is filled with silica sol to 80% of its volume, sealed, and heated to 180-210°C for several hours. Under such conditions small silica particles dissolve and then polymerize on the surface to form layer particles. Thus an inside surface comprising a silica layer is formed. The thickness of the adsorption layer depends on the sol concentration and process duration. The optimum sol concentration is 0.1-0.5%, and the optimum treatment duration is 5-11 h. Columns prepared by this method were used for high-speed analysis of light hydrocarbons. 

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