The coupling of a rotation planar preparative thin-layer chromatography system on-line with mass spectrometry is demonstrated using a simple plumbing scheme and a self-aspirating heated nebulizer probe of a corona discharge atmospheric pressure chemical ionization source. The self-aspiration of the heated nebulizer delivers approximately 20 microL/min of the 3.0 mL/min eluate stream to the mass spectrometer, eliminating the need for an external pump in the system. The viability of the coupling is demonstrated with a three-dye mixture composed of fat red 7B, solvent green 3, and solvent blue 35 separated and eluted from a silica gel-coated rotor using toluene. The real-time characterization of the dyes eluting from the rotor is illustrated in positive ion full-scan mode. Other self-aspirating ion source systems including atmospheric pressure photoionization, electrospray ionization, and inductively coupled plasma ionization, for example, might be configured and used in a similar manner coupled to the chromatograph to expand the types of analytes that could be ionized, detected, and characterized effectively.