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We use spectra and maps of the $J=1-0$ and $J=2-1$ DCO$^{+}$, DCN, DNC, $\rmN_2D^+$ lines and $1_{11}-1_{01}$ ortho- and para-NH$_{2}$D lines, obtainedwith the IRAM-30m telescope, as well as observations of their hydrogenatedisotopologues to study deuteration processes in five high-mass star-formingregions. The temperature was estimated from CH$_3$CCH lines, also observed withthe IRAM-30m telescope, and from NH$_3$ lines, observed with the 100-m radiotelescope in Effelsberg, as well as using the integrated intensity ratios ofthe $J=1-0$ H$^{13}$CN and HN$^{13}$C lines and their main isotopologues.Applying a non-LTE radiative transfer model with RADEX, the gas density and themolecular column densities were estimated. D/H ratios are $0.001-0.05$ forDCO$^{+}$, $0.001-0.02$ for DCN, $0.001-0.05$ for DNC and $0.02-0.4$ forNH$_{2}$D. The D/H ratios decrease with increasing temperature in the range of$\rm 20-40 \,K$ and slightly vary at densities $n(\rm H_2) \sim 10^4-10^6\,cm^{-3}$. The deuterium fraction of $\rm N_2H^{+}$ is $0.008-0.1$ attemperatures in the range of $\rm 20-25\, K$ and at a density of $\sim 10^5\,\rm cm^{-3}$. We also estimate relative abundances and find $ \sim10^{-11}-10^{-9}$ for DCO$^{+}$ and DNC, $ \sim 10^{-11}-10^{-10}$ for $\rmN_2D^+$ and $ \sim 10^{-10}-10^{-8}$ for NH$_{2}$D. The relative abundances ofthese species decrease with increasing temperature. However, the DCN/H$_2$ratio is almost constant ($\sim 10^{-10}$). The observational results agreewith the predictions of chemical models (although in some cases there aresignificant differences).

Variations of the HCO$^{+}$, HCN, HNC, N$_2$H$^+$ and NH$_{3}$ deuterium fractionation in high-mass star-forming regions