Chromatography demonstration using a refrigerator magnet

A ramp made from a flexible sheet refrigerator magnet is used to represent a stationary phase in chromatography. A plastic bead and an iron-core bead are started rolling down the ramp at the same time. The plastic bead has no real attraction to the magnet (representing a chemical substance which is not strongly attracted to the stationary phase) and usually moves more quickly down the magnet than the iron-core bead. The iron-core bead is attracted to the magnet (representing a chemical substance which is attracted to the stationary phase) and usually moves more slowly down the magnet than the plastic bead.
The Bradley University Chemistry Club Demo Crew is grateful for support from the Illinois Heartland Section of the American Chemical Society and the Illinois Space Grant Consortium.