  We present detailed chemical analyses for a sample of twelve stars selected
from the CH star catalogue of Bartkevicius (1996). The sample includes two
confirmed binaries, four objects that are known to show radial velocity
variations and the rest with no information on the binary status. A primary
objective is to examine if all these objects exhibit chemical abundances
characteristics of CH stars, based on detailed chemical composition study using
high resolution spectra. We have used high resolution (R ~ 42000) spectra from
the ELODIE archive. These spectra cover 3900 to 6800 Angstrom in the wavelength
range. We have estimated the stellar atmospheric parameters, the effective
temperature Teff, the surface gravity log g, and metallicity [Fe/H] from LTE
analysis using model atmospheres. Estimated temperatures of these objects cover
a wide range from 4200 K to 6640 K, the surface gravity from 0.6 to 4.3 and
metallicity from -0.13 to -1.5. We report updates on elemental abundances for
several heavy elements, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. For the
object HD 89668 we present the first abundance analyses results. Enhancement of
heavy elements relative to Fe, a characteristic property of CH stars is evident
from our analyses in case of four objects, HD 92545, HD 104979, HD 107574 and
HD 204613. A parametric model based study is performed to understand the
relative contributions from the s- and r-process to the abundances of the heavy
elements.
