Magnetic Resonance Imaging of the HPLC Processelectronic Supplementary Information (ESI) Available: Colour Movie Clips of Three-Dimensional Peak Profile Data. See Http://Www.rsc.org/suppdata/an/b3/b312244a/

Magnetic resonance images have been acquired during reversed-phase liquid chromatography of retained gadolinium chelates. The images can be used to distinguish between columns showing high and low isocratic plate counts and to locate the source of poor performance. Images can be displayed as longitudinal or transverse 2-D plots, as 3-D "movies", or can be manipulated to visualise the analytes' trajectories as a function of time. Such trajectories provide qualitative confirmation of gradient chromatography theory. MRI is a tool with potential to enable targeted improvements in column manufacture and to inform theoretical studies.