  We present preliminary results of a detailed chemical abundance analysis for
a sample of solar-type stars known to exhibit excess infrared emission
associated with dusty debris disks. Our sample of 28 stars was selected based
on results from the Formation and Evolution of Planetary Systems (FEPS) Spitzer
Legacy Program, for the purpose of investigating whether the stellar
atmospheres have been polluted with planetary material, which could indicate
that the metallicity enhancement in stars with planets is due to metal-rich
infall in the later stages of star and planet formation. The preliminary
results presented here consist of precise abundances for 15 elements (C, O, Na,
Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Fe, Co, and Ni) for half of the stars in our
sample. We find that none of the stars investigated so far exhibit the expected
trend of increasing elemental abundance with increasing condensation
temperature, which would result from the stars having accreted planetary
debris. Rather, the slopes of linear least-squares fits to the abundance data
are either negative or consistent with zero. In both cases, our results may
indicate that, like the Sun, the debris disk host stars are deficient in
refractory elements, a possible signature of terrestrial and/or gas giant
planet formation.
