Fragment average isospin distributions are investigated within a
microcanonical multifragmentation model in different regions of the phase
diagram. The results indicate that in the liquid phase versus Z is
monotonically increasing, in the phase coexistence region it has a rise and
fall shape and in the gas phase it is constant. Deviations from this behavior
may manifest at low fragment multiplicity as a consequence of mass/charge
conservation. Characterization of the "free" and "bound" phases function of
fragment charge reconfirms the neutron enrichment of the "free" phase with
respect to the "bound" one irrespectively the localization of the
multifragmentation event in the phase diagram.Comment: 23 pages, 12 figure