  We investigate the effect of Zeeman-splitting on quasiparticle transport in
normal-superconducting-normal (NSN) aluminum single electron transistors
(SETs). In the above-gap transport the interplay of Coulomb blockade and
Zeeman-splitting leads to spin-dependence of the sequential tunneling. This
creates regimes where either one or both spin species can tunnel onto or off
the island. At lower biases, spin-dependence of the single quasiparticle state
is studied and operation of the device as a bipolar spin filter is suggested.
