Pressurized planar electrochromatography of DNS amino acids derivatives in silica gel and silanized silica gel systems with formic acid addition to the water mobile phase

Pressurized planar electrochromatography (PPEC) of dansyl (DNS) derivatives of amino acids in normal- and reversed-phase systems is presented. The results have been obtained for mobile phases with different acetonitrile (ACN) concentrations (0–85%). The data obtained show differences in separation selectivity between high-performance thin-layer chromatography (HPTLC) and PPEC systems. These differences originate from the electrophoretic effect which is involved in the PPEC system, contrary to the HPTLC one.