  A binary quenched-annealed hard core mixture is considered in one dimension
in order to model fluid adsorbates in narrow channels filled with a random
matrix. Two different density functional approaches are employed to calculate
adsorbate bulk properties and interface structure at matrix surfaces. The first
approach uses Percus' functional for the annealed component and an explicit
averaging over matrix configurations; this provides numerically exact results
for the bulk partition coefficient and for inhomogeneous density profiles. The
second approach is based on a quenched-annealed density functional whose
results we find to approximate very well those of the former over the full
range of possible densities. Furthermore we give a derivation of the underlying
replica density functional theory.
