pH-Gradient Liquid Chromatography: Fundamentals and Examples

In this paper, we acquaint the readers with the fundamentals of gradient separation, followed by the latest innovations in this field. We describe the principles of organic modifier- and pH-gradient elution emphasizing the differences and similarities with isocratic separation. The double organic modifier-/pH-gradient is also thoroughly reviewed as a useful method for the simultaneous determination of logk(w) (substitute of logP) and the pk(a) of analytes present in complex mixtures.