Elution curve equation gradient

In addition to the requirement for a minimum displacer concentration to effect a displacement, there is also a constraint on the magnitude of the salt gradient induced by the displacement front. If the induced salt gradient is very large, elution of the protein ahead of the displacer breakthrough may occur. The equation for the elution curve is given by... 

Density gradient ultracentrifugation is used to measure hpoprotein subclasses it is performed in a vertical rotor with measurement of cholesterol continuously in the fractions eluted from the gradient. Mathematical curve resolution derives the component lipoprotein profiles and allows calculation of their cholesterol concentrations. The method can determine concentrations of VLDL, IDL, LDL, Lp(a), and HDL cholesterol. LDL cholesterol subclasses can be expressed separately or combined to give a measurement similar to that provided by the Friedewald equation or beta-quantification. A disadvantage is that the procedure is technically demanding and requires instrumentation not usually available in clinical laboratories. 

The retention factors of the polymers in 60 % THF were calculated from gradient elution and discussed together with those directly measured for oligomers with 2-12 repeat units or 2000, 4000, and 9000 g/mol molar mass. On a lOOnm-pore packing, the Martin equation was fulfilled for n = 19 repeat units. At higher values, the curve... 

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 Thus, the assumption of local equilibrium is no longer valid.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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