  The standard interstellar ratio of deuterium to hydrogen (D/H) atoms is $\sim
1.5 \times 10^{-5}$. However, the deuterium fractionation is in fact found to
be enhanced, to different degrees, in cold, dark cores, hot cores around
massive star forming regions, lukewarm cores, and warm cores ({\it hereafter},
hot corinos) around low-mass star forming regions. In this paper, we
investigate the overall differences in the deuterium chemistry between hot
cores and hot corinos. We have modelled the chemistry of dense gas around
low-mass and massive star forming regions using a gas-grain chemical model. We
investigate the influence of varying the core density, the depletion efficiency
of gaseous species on to dust grains, the collapse mode and the final mass of
the protostar on the chemical evolution of star forming regions. We find that
the deuterium chemistry is, in general, most sensitive to variations of the
depletion efficiency on to grain surfaces, in agreement with observations. In
addition, the results showed that the chemistry is more sensitive to changes in
the final density of the collapsing core in hot cores than in hot corinos.
Finally, we find that ratios of deuterated sulphur bearing species in dense gas
around hot cores and corinos may be good evolutionary indicators in a similar
way as their non deuterated counterparts.
