Retention diagrams calculated

Fig. 5.16. — The retention diagrams calculated for 1 — uniform thickness, /, of polymer film 2 — I Al distribution of thicknesses.

Fig. 5.17. — The effect of crystallinity upon retention diagrams calculated at the degrees of crystallinity indicated [209].

Specific retention volumes and calculated 12 values for the three sets of polymer-probe pairs are given in Tables II to IV. In all cases, specific retention volumes were corrected for support retention. Retention diagrams for polystyrene and PMMPO are shown in Figures 2 to 3. 

Figure 18.14 Window diagram. The separation was performed with a linear gradient from 0 to 45% B and the optimum runtime needs to be found out. (a) Gradient in 15 min (b) gradient in 45 min with some elution orders reversed (c) window diagram calculated from the initial two experiments with a linear relationship between retention time and %B assumed the plot shows the resolution / of the peak pair which is critical under the respective conditions it is necessary to use long gradient runtimes to obtain a good resolution (d) optimized chromatogram with 0-45% B in 80 min, but separation is already finished after 45 min and 25% B.

Fig. 5.15. — The effect of polymer film thickness on retention diagrams of n-hexadecane on polystyrene (a) calculated (b) experimental [209]. Film...

Calculation of retention diagrams for a film of uniform thickness I and for that of thickness distributoin I + Al yields a gradual deviation... 

Provided that the melting curve is known, eqn (5.77) describes the variation of retention volume through Tg as well as T . The effect of crystallinity upon calculated retention diagrams, for crystallinities of 0, 50 and 85% and identical polymer film thicknesses, is shown in Figure 5.17 [209 . ... 

The retention diagrams of n-hexadecane on polystyrene calculated for three different flow rates ranging between F and 9F are plotted in Figure 5.18 a the experimental data for the flow rates are also plotted for com-... 

The effect of the I, location on calculated retention diagrams under identical conditions of solute-polymer interaction and film thickness is... 

Fig. 5.19. — The effect of the glass transition on calculated retention diagrams [209].

Basically, if the contributions of adsorption and dissolution to retention volume and to ie/F value are known at a given temperature, eqn (5.85) makes possible the calculation of the corresponding peak shape the temperature dependence of peak shapes yields the complete retention diagram. This is not entirely possible iM cause of the simplifications included... 

The basis of chromatography is in the differential migration of chemicals injected into a column. The carrier fluid takes the solutes through the bed used for elution (mobile phase). The bed is the stationary phase. Based on mobility, the retention-time detectors identify the fast and slow-moving molecules. Based on internal or external standards with defined concentration, all unknown molecules are calculated in a developed method by software. GC columns are installed in an oven which operates at a specified temperature. A diagram of an oven with GC column is shown in Figure 7.16. 

Figure 7.2 Diagram of a TLC plate. The plate is suspended vertically in the solvent containing the compounds to be separated (the solvent level or origin), and over time the compounds and solvent migrate up the plate to different heights and are separated. The retention factor (Rf) for compound 1 is calculated as AB/ AD, and for compound 2 AC/AD.

An advantage of using S is that it can be calculated from retention data commonly supplied by electronic integrators and/or data systems, facilitating the window diagram search (vide infra). 

Colin et al. [SSS] have described a different method to construct a diagram that allows the prediction of optimum conditions. Their approach is based on the calculation of so-called critical bands. If the retention surface of a solute j is known, then a forbidden zone may be defined below the capacity factor kj. If the preceding solute i has a capacity factor kp which falls in this critical band, then the resolution between i and j is insufficient. Eqn.(1.20) relates the resolution to the capacity factors of the individual solutes ... 

Theoretical studies by E. Ruch (173-177) proved the correctness of this concept of the bonding, with which the retention of the aromatic character of the ring is in harmony. The nature of the bonding in the dicyclopentadienyl metal compounds was discussed by him in terms of molecular and equivalent orbitals, and on the basis of calculated overlap integrals for ferrocene an energy-level diagram was suggested which... 

A pre-requisite for fault seal analysis is a consistent structural model, with sufficient detail and proper fault linkage relationships. The first step of static fault seal analysis (Fig. 2) involves the construction of a juxtaposition diagram (Allan, 1989), in which areas where reservoir is juxtaposed against a sealing lithology are identified. The retention capacity is calculated from the minimum capillary entry pressure of the juxtaposed lithology, which can be measured or... 

Window diagram Window diagrams, developed by Laub and Purnell for optimizing the composition of mixed stationary phases in gas chromatography, can be used for optimizing mobile phase composition in LC. From two initial experiments (if a linear relationship is assumed between log k and mobile phase composition) or more (in the case of a quadratic relationship), the retention models are calculated for all solutes, and a response function (selectivity between every possible pair of solutes) is calculated and plotted versus the mobile phase composition. Areas or windows in which all solutes are separated can be located graphically. No particular effort of computation is required in such a procedure. 

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