Prediction of Retention Temperatures in Programmed Temperature Gas Chromatography. A Descriptive Equation and Computational Method

Elementary theory of programed temperature gas chromatography

“…This time must equal the time needed to increase the temperature by 30 degrees since the intervals are defined in terms of 30 degree units of change. This time is equal to the 30 degrees divided by the programed rate of increase of temperature with respect to time, p, i.e., interval migration time = 30°/d-Equating the two times we find that the mean (and presumably uniform) (ft values of the last segment, Sh, is (Ri -0P/6O (8) We know that elution itself occurs right at the end of the final segment rather than in the middle where mean values are applicable. We also know that (R doubles as it passes from the beginning to the end of the seg- then.…”

Gas Chromatography and Its Application to Pharmaceutical Analysis

“…2). With a linear temperature rise, each solute is eluted a t a characteristic retention volume in the same way as for isothermal gas chromatography (96). The theoretical aspects of temperatureprogramed gas chromatography have been discussed by Giddings (97) where the subscripts 1 and 2 stand for the sample component and the standard, respectively, V R is the net uncorrected retention volume, and t is the net retention time measured from the air peak to the sample peak.…”

“…2). With a linear temperature rise, each solute is eluted a t a characteristic retention volume in the same way as for isothermal gas chromatography (96). The theoretical aspects of temperatureprogramed gas chromatography have been discussed by Giddings (97) and Said (98).…”

Capillary Programmed Temperature Gas Chromatography. Some Theoretical Aspects.

“…The fact that eddy diffusion is, under some circumstances, a real phenomenon is demonstrated by the existence of at least three approximate derivations which all agree as to the order of magnitude of the effect. These derivations employ a similitude principle (23), a mixing stage model (5,25) (very much like a plate height model), and a random walk model (9). They all predict a plate height contribution, A, which is proportional to the particle size (for geometrically similar packing) and independent of all nongeometrical parameters such as flow velocity and temperature.…”