  We present high-resolution, high signal-to-noise UVES spectra of AO Vel, a
quadruple system containing an eclipsing BpSi star. From these observations we
reconstruct the spectra of the individual components and perform an abundance
analysis of all four stellar members. We found that all components are
chemically peculiar with different abundances patters. In particular, the two
less massive stars show typical characteristics of HgMn stars. The two most
massive stars in the system show variable line profiles indicating the presence
of chemical spots. Given the youth of the system and the notable chemical
peculiarities of their components, this system could give important insights in
the origin of chemical anomalies.
