Plate height volume

Elution volume, exclusion chromatography Flow rate, column Gas/liquid volume ratio Inner column volume Interstitial (outer) volume Kovats retention indices Matrix volume Net retention volume Obstruction factor Packing uniformity factor Particle diameter Partition coefficient Partition ratio Peak asymmetry factor Peak resolution Plate height Plate number Porosity, column Pressure, column inlet Presure, column outlet Pressure drop... 

Recovery factor Reduced column length Reduced plate height Reduced velocity Relative retention ratio Retardation factor d Retention time Retention volume Selectivity coefficient Separation factor... 

The important parameters to consider are the selectivity (dKJdlogR), the ratio of pore volume, Vp, over void volume, Vq, the plate height, H, and the column length, L. The distribution coefficient, Kq, has a slight effect on resolution (with an optimum at Kp 0.3-0.5). In addition to this, extra column effects, such as sample volume, may also contribute to the resolution. 

Why does plate height depend on linear flow rate, not volume flow rate ... 

Figure 8.2 Effects of sequential injection sample volume on peak height and plate height of FITC-labeled amino acids [23].

Partition coefficient, 9, 10 Partition ratio, 11 time optimization of, 57-58 Peak, definition of, 69 Peak capacity, 18, 19 Pellicular supports, 157 Permeability, 63-64 Phase selection diagrams, 218-219 Phase volume ratio, 11 Pinkerton (ISRP) columns, 225-226 Plate height, 17 Plate number, 14-16 Plate theory, 3, 28 Polarity index, 210, 211 Pore size of LC supports, 157 Porosity, 27 Precision, 99-100 Preparative scale ... 

One effect of pore flow is that it enhances the mass transfer rate between the pore and interstitial volumes. Instead of by molecular diffusion only, which is by nature slow in solution, mass exchange occurs also by perfusive EOF. This effect can be treated as a form of stimulated diffusion. Following the original treatment for pressure-driven LC according to Rodrigues et al. [31], the plate height contribution from stationary-phase mass transfer resistance HCs in the presence of pore flow can be written as... 

An example is shown in Figure 8-71, where the column stability was evaluated with two different buffers, phosphate buffer ("pFI 11) and 1-methyl piperidine (wpH 11) [43]. Plots of H (plate height) or N versus number of column volumes can be generated. Remember that H is inversely proportional to the efficiency ... 

Figures 24-8 and 24-9 and Example 24-5 illustrate why capillary columns, lightly loaded columns, and columns operated under conditions where the solutes have low partition ratios have never entirely lived up to the promise of their sometimes enormous plate numbers or small plate heights. In fairness, it should be pointed out that capillary and lightly loaded columns are frequently used under conditions where high specific retention volumes partly compensate for the loss of separating efficiency resulting from the large dead space in these columns.

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