Chromatography elution curve equation

Equation (10) is the basic elution curve equation it is a Poisson function, but when n is large, the function approximates to a normal error function or Gaussian function. In practical chromatography systems, n is always greater than 100 and, thus, all chromatographic peaks will be Gaussian or nearly Gaussian in shape. 

It should be emphasized that this broadening cannot help any separation. Still, Eq. 4.23 does find an application — it is the measurement of l) 2 for two non-adsorbable gases. In a chromatography-like experiment, the flow of a gas is spiked with a little of the other the elution curve is recorded, and E>i,2 is evaluated from the curve width. Equation 4.23 then serves to account for the nonzero flow velocity [13],... 

Gel permeation chromatography (GPC) is a convenient and reliable method to determine the entire molecular weight distribution (mwd) of a polymer. In general, the resulting elution curve D(V ), where is the elution volume is related to the mwd by Tung s integral equation... 

This equation was derived by comparison of the elution curve approximated by the normal distribution and the equation derived from the plate theory The similarity of Eqs (10-11) and (10-12) is not surprising Eq (10-11) can be considered to be a more generalized form Eq (10-11) is further simplified in the cases of liquid phase chromatography since the contribution of the first term of R H S becomes negligible since molecular diffusion in liquid phase is small... 

The feasibility of Kj determinations in the context of one-atom-at-a-time chemistry is very promising and the collection of Kj values will allow establishment of reliable variations of the chemical properties (complexation, hydrolysis) of elements within a group, for comparison with theoretical predictions, and, perhaps, for determination of thermodynamic constants. Moreover, other information can be derived from chromatography experiments. The mathematical treatment of elution curves can be carried out with various models, especially Glueckauf s, which offers the advantages of using simple equations and takes into account the possible dissymmetry of elution bands [31, 32]. The parameters included in Glueckauf s equations allow the determination of the distribution... 

The VERSE method was extended to describe the consequences of protein de-naturation on breakthrough curves in frontal analysis and on elution band profiles in nonlinear isocratic and gradient elution chromatography [45]. Its authors assumed that a unimolecular and irreversible reaction taking place in the adsorbed phase accormts properly for the denaturation and that the rate of adsorption/desorption is relatively small compared with the rates of the mass transfer kinetics and of the reaction. Thus, the assumption of local equilibrium is no longer valid. Consequently, the solid phase concentration must then be related to the adsorption and the desorption rates, via a kinetic equation. A second-order kinetics very similar to the one in Eq. 15.42 is used. 

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