Zero length chromatography

Kinetics and diffusion Steady-state isotopic transient kinetic analysis (SSITKA) Temporal analysis of products (TAP) Tapered element oscillating microbalance (TEOM) Temperature scanning reactor (TSR) Zero length chromatography (ZLC) Pulsed field gradient NMR... 

The Zero-length Column Chromatography (ZCC) method was used (5). Between 10-50 mg of catalyst, 150 cm /min He flow and a concentration of C2H4of 500 ppm were employed. Ethylene was adsorbed at different temperatures till the saturation of the sample was achieved. The hydrocarbon flow was then stopped and its concentration was measured during... 

As we continue lowering the pressure, GC is the final limiting case when the mobile phase has zero solvent strength over the entire column length and where temperature is the only effective control parameter. Gas chromatography is shown in Figure 7.3. 

The catalytic activity of the silylated and the non-silylated Ti-MCM-41 materials was tested in epoxidation of cyclohexene using tercbutylhydroperoxide (TBHP) as oxidant. In a typical catalytic run 56 mmol of olefin were mixed with 14 mmol of TBHP (olefin/TBHP ratio = 4) at the reaction temperature, 60°C. Under these reactions conditions the water content was 2 wt.%. Then, 30 mg of catalyst (0.5wt% catalyst) were added to the reaction medium. This instant was taken as time zero of reaction, and aliquots of the reaction media were withdrawn at different reaction times and subsequently analyzed by Gas Chromatography using a 5 % phenylsilicone column (HP-5) of 25 meters length. 

Figure 6 shows a chromatogram for linear elution chromatography. The amount of probe injected is set to the amount corresponds to the limit of sensitivity of the detector. The retention time, tR, is the time that the average molecule of probe takes to travel the length of column. And the time is measured to be the midpoint of the symmetrical curve for nonpolar probes and to be a position at which the total area of the asymmetrical curve for polar probes is divided into equal areas. The time, to, is the zero retention time reference measured with a non adsorbing probe such as methane simply to pass through the column space from inlet to out let. 

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