Application of the solvatic model for prediction of retention in RP‑LC for multi‑step gradient profiles

Application of the solvatic retention model of reversed-phase liquid chromatography was studied to predict retention of phenylisothiocyanate derivatives of amino acids from structural formulae and stationary and mobile phase properties. The gradient elution mode with methanol and acetonitrile aqueous mobile phases was used. It was shown that practically acceptable prediction or retention time values can be achieved after the first approximation step when experimental data of one run are used. The zero approximation level predictions—from structural formulae, column and mobile phase properties can be used as a “first guess” method from which further optimization can begin.