Two-dimensional (2D) separation of eight amino acids has been achieved by HPTLC in the first dimension and pressurized planar electrochromatography (PPEC) in the second, orthogonal, dimension. Separation selectivity in PPEC was very different from that in HPTLC. This attribute of these systems enabled complete separation of the amino acids. Chromatography was performed on reversed-phase plates with acetonitrile-buffer mobile phase. PPEC was performed after complete prewetting the plate, including the sample zones.
J. Kupec, S. Turina, Chromatographia 10 (1977) 157–159.