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Effects of the gradient profile on the production rate in reversed-phase gradient elution overloaded chromatography

1997; Elsevier BV; Volume: 760; Issue: 1 Linguagem: Inglês

10.1016/s0021-9673(96)00811-4

1873-3778

Pavel Jandera, David Komers, Georges Guiochon,

Crystallization and Solubility Studies

Band profiles in overloaded gradient elution reversed-phase chromatography were calculated using the experimental parameters of the distribution isotherms of binary mixtures of phenol and o-cresol determined by binary frontal analysis with automatic, on-line analysis of the composition of the breakthrough curve plateaus. The dependencies of the isotherm coefficients on the composition of the mobile phase were described by three-parameter equations and used in the numerical calculations. Calculated band profiles of the sample components determined the fraction range, recovery yield and production rate necessary to obtain the required purity of the sample components with various loading factors and concentration ratios of sample components depending on the gradient profile. The production rate in preparative gradient elution HPLC depends more on the initial concentration of the stronger eluent than on the steepness of the gradient. The highest production rates can be achieved with steep gradients starting in pure water, where the sample-focusing effect is the strongest, provided feed solubility is adequate.