We formulate the many-body spin dynamics at high temperature within the non-equilibrium Keldysh formalism. For the simplest AY interaction, analytical expressions in terms of the one particle solutions are obtained for linear and ring configurations. For small rings of even spin number, the group velocities of excitations depend on the parity of the total spin projection. This should enable a dynamical filtering of spin projections with a given parity i.e., a spin projection chromatography. (C) 2003 Elsevier B.V. All rights reserved.