ABSTRACT
The technique of gradient elution is a solution to certain problems which are often encountered in isocratic liquid chromatography. Whereas isocratic elution is carried out with a mobile phase of fixed composition, in gradient elution the mobile phase is intentionally varied during a chromatographic run. While this change in mobile-phase composition can take various forms, gradient elution almost always involves an increase in solvent strength from the beginning to end of the separation, as a result of mixing a stronger solvent B with a weaker solvent A. The effective use of gradient elution requires an understanding of how separation varies with experimental conditions. The effective use of gradient elution requires an understanding of how separation varies with experimental conditions.
