By fitting the revised Hipparcos intermediate astrometric data (HIAD), we obtain the photocentric orbital solutions of some single-lined spectroscopic binaries (SB1s) in the 9th Catalogue of Orbits of Spectroscopic Binaries (SB9). For SB1s with relatively small magnitude difference between the two components, we find that the primary orbit is not a good approximation of the photocentric orbit in their orbit determination and suggest that future spectroscopic observations and advanced spectral separation techniques should be applied to these systems. In order to facilitate these future observations, we also estimate the full orbital solutions and provide the observational ephemerides. As an example, we give the result for HIP 113860.