  In a recent publication [Phys. Rev. B $\textbf{89}$, 155403 (2014)], the
authors investigated the spectrum of a Coulomb impurity in graphene in the
presence of magnetic and electric fields using the coupled series expansion
approach. In the first part of their publication they investigated how Coulomb
impurity states collapse in the presence of a perpendicular magnetic field. We
argue that the obtained spectrum does not give information about the atomic
collapse and that their interpretation of the spectrum regarding atomic
collapse is not correct. We also argue that the obtained results are only valid
up to the dimensionless charge $\mid \alpha\mid=0.5$ and in order to obtain
correct results for $\alpha>0.5$ a proper regularisation of the Coulomb
interaction is required. Here we present the correct numerical results for the
spectrum for arbitrary values of $\alpha$.
