  There are 23 long-period binary systems discovered to date that contain a
B-type hot subdwarf(sdB) whose orbital parameters have been fully solved. They
evolve into O-type subdwarfs (sdO) once the helium burning transitions from the
core to the He shell. Their study will help constraint parameters on the
formation and evolution of these binaries and explain some of their puzzling
features. In this study, we aim to solve orbital and atmospheric parameters of
two long-period sdO binaries and, for the first time, investigate the chemical
composition of their main-sequence (MS) companions. HERMES high-resolution
spectra are used to obtain radial velocities and solve their orbits. The Grid
Search in Stellar Parameter code (GSSP) is used to derive the atmospheric
parameters and photospheric chemical abundances of the MS companions. Stellar
evolution models (MIST) are fitted to the companion atmospheric parameters to
derive masses. In the bimodal period-eccentricity diagram, the orbital
parameters indicate that Feige 80 matches the same correlation as the majority
of the systems. The analysis suggests that Feige 80 has a canonical subdwarf
mass and followed a standard formation channel. However, BD-11$^{\rm{o}}$162 is
an exceptional system with a lower mass. It also shows a carbon overabundance,
which could be caused by a higher progenitor mass. The yttrium depletion in
both MS companions could indicate the existence of a circumbinary disk in these
systems' pasts. Nevertheless, a chemical analysis of a larger sample is
necessary to draw strong conclusions.
