Prediction of experimental parameters in combined isocratic and gradient elution reversed phase high performance liquid chromatography (RP‐HPLC) using acetonitrile as organic modifier

Abstract

AbstractThe use of gradient elution in RP‐HPLC is increasing. Aqueous buffers, such as phosphate at pH 1.7, with acetonitrile as the organic modifier are particularly advantageous as eluents with linear elution strength (LES). In the isocratic mode, under the experimental conditions used, fairly good linearity exists between logk' and xB (x is the volume ratio of the organic modifier, i.e. acetonitrile) with a correlation coefficient of 0.9995. The relationship between isocratic and gradient elution parameters, such as xB, x (starting composition in gradient elution), m (slope of the linear gradient), is transparent and the parameters of interest can be predicted fairly accurately using simple equations. The proposed system could be used in elaboration of a general retention index system for organic molecules in RP‐HPLC.