Small particle liquid chromatography temperature

The experiments were carried out in a small flow type fixed bed reactor which has been described in a recent publication (9) along with the methods of analysis by capillary gas-liquid chromatography. Results are reported that were gained with all pure n-alkanes ranging from n-hexane to n-dodecane. Feed hydrocarbons were delivered from Fluka, Buchs, Switzerland (purum). Purity exceeded 99. 5 wt. -% in any case. The Pt/Ca-Y-zeolite catalyst (0. 5 wt. -% Pt, SK 200, Union Carbide, Linde Division volume of catalyst bed 2 cm3 particle size 0. 2 - 0. 3 mm) was calcined in a dried stream of Ng and activated in a dried stream of at atmospheric pressure prior to use. The mass of dry catalyst was 1.0 g. The total pressure and molar ratio hydrogen n-alkane were kept constant at 39 bar and 17 1, respectively, whereas the reaction temperatures and space velocities were varied. 

Y. Xiang, B. Yan, B. Yue, C. V. McNeff, P. W. Carr, and M. L. Lee, Elevated-temperature ultrahigh-pressure liquid chromatography using very small polybutadiene-coated nonporous zirconia particles, /. Chromatogr. A 983 (2003), 83-89. 

An alternative strategy for fast liquid chromatography uses short columns packed with small particles operated at high flow rates and often elevated temperatures to separate simple mixtures under conditions were resolution is compromised but still adequate for identification purposes [252-258]. Small diameter particles provide larger plate numbers by virtue of their relatively small interparticle mass transfer resistance combined with a shallow increase in the reduced plate height as the reduced mobile... 

In gas-solid chromatography the packing of columns consists of small adsorbent particles, while in gas-liquid chromatography the stationary phase, which is liquid at the operating temperature, is coated on small solid support particles. The solid support retains the stationary liquid phase on its surface and increases the surface area of contact between liquid and gas phases. The choice of an appropriate support is governed by several requirements, such as chemical inertness towards the sample components, lai e specific surface area, mechanical strength, spherical shape of particles to reduce the pressure drop along the column, narrow... 

The particle method is carried out as follows. Several particles of Chromosorb W AW (acid washed a commercially available support for the liquid phase in gas chromatography) were placed on a watch glass, and 5 pi of a diethyl ether or ethyl acetate solution of the test compound, adjusted to an appropriate concentration, was dripped carefully on to these particles. Any excess solution on the watch glass was immediately absorbed with a piece of filter paper, and the particles were then air-dried at room temperature. A few of the treated particles were then dropped into an aqueous suspension of zoospores in a small Petri dish (see above). The behaviour of zoospores around the particles was observed microscopically after a period of 1 min. Control particles were treated with ether or ethyl acetate only. 

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