  We analyze the results obtained from a model consisting of the interaction
etween the electric quadrupole moment of a moving particle and an electric
field. We argue that the system does not support bound states because the
motion along the $z$ axis is unbounded. It is shown that the author obtains a
wrong bound-state spectrum for the motion in the $x-y$ plane and that the
existence of allowed cyclotron frequencies is an artifact of the approach.
