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Chromatographic column isothermal operation

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. [Pg.250]

The behavior of chromatographic columns operated in gradient elution, under linear conditions i.e., assuming linear isotherms for all the solutes) has been studied theoretically by numerous authors [2,4-10]. The most comprehensive treatment is that based on the linear solvent strength (LSS) theory of Snyder et al. [5,6]. This theory has formd widespread acceptance [7,8] and has been extended to include the contributions of the various mass transfer resistances to band broadening [9-11]. It assumes the injection of infinitesimal pulses of a feed and a linear gradient of the volume fraction of a mobile phase modifier, cf). [Pg.701]

The analysis was performed using a capillary column with intermediate polarity (SPB 608-Supelco, 30m x 0.25 mm i.d, 0.25 pm film thickness) with a Perkin-Elmer 8310 gas chromatograph equipped with electron capture detector. Isothermal oven conditions were applied (210°C), the temperature of the injector was 260 °C and of the detector - 400°C. The column was operated with a helium carrier gas (99.996%) with 190 kPa head column pressure. The detector makeup gas consisted of 5% methane and 95% argon. The runtime was set at 40 min. [Pg.376]

The simplest equilibrium model of a chromatographic column assumes isothermal operation, plug fluid flow, infinitely fast mass transfer between fluid and sohd phases (instantaneous equilibrium at the interface), negligible pressure drop and trace system. The model equations are the mass balance in a bed volume element and the equilibrium law at fluid/solid interface ... [Pg.189]

This equation applies only to isothermal operation. In TEQA, our interests tend to be directed toward the lower end of Ri, although it is good to be aware of such limitations on the high end. We now continue on in our journey through a GC by moving on to what many chromatographers call the heart of the chromatograph, the GC column. [Pg.302]

In LGC, a single long capillary column is typically used in a temperature-programmed mode to perform the separation. Although this same separation scheme can be used in PGC, the major drawback is the speed of analysis. The solution is to use multiple column trains and column-switching techniques. This allows the chromatograph to be operated in an isothermal mode. [Pg.3867]

For isothermal operation, constant pressure is sufficient to provide a constant flow rate, assuming that the column has a constant pressure drop. For simple, inexpensive gas chromatographs which run only isothermally, the second part of the flow control system may be a simple needle valve this, however, is not sufficient for research systems. [Pg.119]

Krishen [78] used a dual flame ionisation chromatograph equipped with a 1 mV recorder. Two stainless steel columns each 1.8 m x 13 mm od packed with 10% UCW-98 on 60-80 mesh Diatoport S were employed in the dual operation mode. The initial column oven temperature was 100 °C and after 4 minutes of isothermal operation, the temperature was programmed at a rate of 8 C per minute to a maximum of 330 C. The final temperature was held constant for 8 minutes. The injection block and the detector were maintained at 270 °C. The helium, hydrogen, and air pressures were 0.4 (Flowrator 0.8), 0.09, and 0.2 MPa, respectively. [Pg.185]

Isothermal operation of a chromatographic column has a number of drawbacks, as illustrated in the scenario depicted for the separation of lime oil in Figure 3.62. If the selected isothermal column temperature is too low, the early-eluting peaks will... [Pg.182]

Wurst O has described a gas chromatographic method using a gas density balance detector for the determination of chlorinated phenyl chlorosilanes. Separation is achieved on a column (2 metres x 4mm) packed with Celite 545 supporting 10% of Lukopren G 1000 (a Silicone elastomer), with nitrogen (60ml per minute) as carrier gas. The column was operated isothermally at various temperatures from 140 -... [Pg.175]

A 100 mg amount of sample and 2 ml of reagent are mixed in a 20 ml round-bottomed flask and the mixture refluxed on an oil-bath at 120 C for 2 hours. The contents of the flask are cooled to room temperature and then neutralised with 50% aqueous sodium carbonate solution, followed by extraction with about 20 ml of diethyl eflier. The ether layer is washed with de-ionised water and concentrated to a small volume on a steam bath the concentrate is then injected into the gas chromatograph. The FFAP column is operated isothermally at the appropriate temperature for the purpose of both identifying the base compounds and determining their oxyethylene groups contents. For the analysis of the polyether based on 1,2-diaminoethane or 2,2 -diaminodiethylamine the SE-30 column is used. [Pg.314]

Chromatograph—Place the proper column and sample volume in operation for the desired run in accordance with 8.1 and 8.2. For isothermal operation, the column should be maintained at a temperature between 30 and 45°C. When appropriate, column temperatures may be increased. Adjust the operating conditions and allow the instrument to stabilize. Check the stability by making repeat runs on the reference standard to obtain reproducible peak heights as described in 5.4.2 for corresponding components. [Pg.305]

Independent Temperature Control—Haas test method requires the temperature control of five columns, column switching valves and sample lines. The columns consist of polar, non-polar, Tenax, platinum, and molecular sieve columns. The specifications for these columns are listed in Table 1. The polar column, non-polar column, column switching valves, and sample lines require isothermal operation at a temperature equivalent to e temperature of the gas chromatograph oven. These components may be located in the gas chromatograph oven. The Tenax column, platinum column, and molecular sieve column require operation at temperatures other than the gas chromatograph oven temperature. These columns may be temperature controlled by any means that will meet the following specifications ... [Pg.891]


See other pages where Chromatographic column isothermal operation is mentioned: [Pg.76]    [Pg.555]    [Pg.218]    [Pg.307]    [Pg.333]    [Pg.368]    [Pg.225]    [Pg.595]    [Pg.349]    [Pg.106]    [Pg.278]    [Pg.302]    [Pg.152]    [Pg.152]    [Pg.62]    [Pg.37]    [Pg.755]    [Pg.296]    [Pg.144]    [Pg.890]    [Pg.1932]    [Pg.878]    [Pg.2438]    [Pg.237]    [Pg.381]    [Pg.201]    [Pg.456]    [Pg.214]    [Pg.211]    [Pg.459]    [Pg.545]    [Pg.224]    [Pg.22]    [Pg.16]    [Pg.417]    [Pg.37]    [Pg.81]    [Pg.347]   
See also in sourсe #XX -- [ Pg.182 ]




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Chromatographic column

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