Investigation of the chromatographic behavior and retention times of peptide on amino, cyano, diol, silica and amide columns in normal-phase LC

An experimental procedure for peptide separation by normal-phase liquid chr omatography (NPLC) was proposed in previous papers. In the present study, t he chromatographic behavior of amino, cyano, amide, diol and silica columns , which have been used in non-aqueous NPLC, was newly investigated. The ami no column was not appropriate for this peptide separation because of poor r ecovery. The cyano column could not be used due to a lack of retention. The amide, diol and silica columns were useful for peptide separation. The chr omatograms on amide, diol and silica columns were slightly different when t he mobile-phase composition was changed. Furthermore, the relationship betw een the retention time and the amount of modifier in the mobile phase was i nvestigated with each column, There was a linear relationship between the l ogarithm of the retention factor and the logarithm of the modifier ratio in each column.