Isothermal gas chromatograph

Thomsberra, W. L. Isothermal gas chromatographic separation of carbon dioxide, carbon sulfide, hydrogen sulfide, carbon disulfide and sulfur dioxide. Anal. Chem. 

Fig. 10. Relative yield of Db (triangles) measured in an isothermal gas chromatographic experiment with purified HC1 as reactive gas. Reproduced from [22] with the permission of Oldenbourg Verlag. For comparison, the data for Nb measured under identical gas chemical conditions from Figure 8 are also shown.

Although the Isothermal gas chromatographic column did not measure the heavy ends correctly, the results obtained with It give good comparisons of the composition and quality of the alkylates on essentially a heavy-end-free basis. These qualities are reported as the research octane number (RON) that was calculated (2) based on the composition of the alkylates as determined analytically. On essentially a heavy-end-free basis, RON values of 98-101 were common. Reanalyses of the alkylate In order to determine the heavy ends more correctly Indicated that the above RON values were In general too high by 3-4 units. RON values of 94.5 to 98 are thought to have occurred. 

The combustion stability limits, size of the recirculation zone, completeness of combustion, and the radial distribution of mean temperatures have been measured. Mean temperatures were measured with a 0.076-mm Pt vs. Pt-13% Rh thermocouple coated with silica to reduce catalytic eflFects. The completeness of combustion was measured with gas chromatography using a Pye Unicam isothermal gas chromatograph. A detailed description of the measurement technique used is given in Refs. 5 and 9. 

Ne,4n) reaction, was used to compare the volatility of the oxychlorides of Bh with those of its group-7 homologs Re and Tc in on-line isothermal gas chromatographic experiments [15]. Six decay chains of Bh were observed over nearly a month of irradiation time. The relative 3uelds vs. isothermal temperature ciuwes are shown in Fig. 29. 

Isothermal Gas Chromatographic Method for the Rapid Determination of Car-bamazepine (Tegretol) as Its TMS Derivative... 

Figure 4.14 shows a screen dump of an isothermal gas chromatographic simulation from a commercial gas chromatographic optimization program. The Temperature, Pressure, and Column tabs in the display permit the user to set elution conditions, including multiramp temperature and pressure programming, which were not exercised for this example. The Auto-Optimize tab carries out a minimum-resolution-oriented optimization calculation, which determines a set of conditions that lie within specified limits and meet the minimum resolution criterion. 

Reaction vessel. Use a small tube or vial fitted with a Teflon-lined screw cap. Gas chromatograph. Operate the column isothermally at 210 °C using a flame ionisation detector. 

FIGURE 8 Gas chromatographic separation of the volatiles of D. diemensis egg extracts (47). Conditions fused silica column OV 1 (10 m X 0.32 mm) 50°C isotherm for 2 min, then at 10°C/min to 250°C injection port 250°C detector Finnigan ion trap, ITD 800 transfer line at 270°C electron impact (70 eV) scan range, 35-250 Da/sec. For identity of numbered compounds refer to Figure 9. 

Catalytic tests were performed in an isothermal flow quartz reactor apparatus under atmospheric pressure, provided with on-line gas chromatographic (GC) analysis of the reagent and products by two GC instrument equipped with flame ionization and thermoconducibility detectors. The activity data reported refers to the behavior after at least two hours of time on stream, but generally the catalytic behavior was found to be rather constant in a time scale of around 20 hours. 

The feed gas flow rate was monitored and controlled by mass flow controllers. Product gases were fed through heated stainless steel lines to a sample loop in an automated gas chromatograph. The GC analysis was performed using two isothermal columns (80°C) in series, a Porapak T and a Molecular Sieve 5A column. When necessary, a second GC analysis using a temperature programmed Hayesep R column was used to separate and detect small hydnx arbons (such as ethylene and ethane) and H2O. 

Materials and instrumentation. Experiments were performed using a special home-made cell coupled to a dual current supply with a maximum output of 10 V/40 mA. A detailed technical description of this system is published elsewhere (10). H NMR spectra were recorded on a Varian Mercury vx300 instrument at 25 °C. GC analysis was performed on an Interscience GC-8000 gas chromatograph with a 100% dimethylpolysiloxane capillary column (DB-1, 30 m x 0.325 mm). GC conditions isotherm at 105 "C (2 min) ramp at 30 °C min to 280 °C isotherm at 280 °C (5 min). Pentadecane was used as internal standard. The ionic liquid [omim] [BF4] was prepared following a published procedure and dried prior to use (8). All other chemicals were purchased from commercial sources (> 98% pure). 

Catalytic activities for n-hexane cracking were performed using an isothermally operated flow reactor. The feed stream of nitrogen was saturated at 3°C with hexane. With the help of a bypass it was possible to determine both the reactor inlet and outlet concentration of hexane using a gas chromatograph (Varian Star 3400) with FID-detector. 

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