  The mass of protoplanetary disks is arguably one of their most important
quantities shaping their evolution toward planetary systems, but it remains a
challenge to determine this quantity. Using the high spatial resolution now
available on telescopes such as the Atacama Large Millimeter/submillimeter
Array (ALMA), recent studies derived a relation between the disk surface
density and the location of the "dust lines". This is a new concept in the
field, linking the disk size at different continuum wavelengths with the radial
distribution of grain populations of different sizes. We aim to use a dust
evolution model to test the dependence of the dust line location on disk gas
mass. In particular, we are interested in the reliability of the method for
disks showing radial substructures, as recent high-resolution observations
revealed. Our models show that the determination of the dust line location is a
promising approach to the mass estimate of protoplanetay disks, but the exact
relation between the dust line location and disk mass depends on the structure
of the particular disk. We calibrated the relation for disks without evidence
of radial structures, while for more complex structures we ran a simple dust
evolution model. However, this method fails when there is evidence of strong
dust traps. It is possible to reveal when dust evolution is dominated by traps,
providing the necessary information for when the method should be applied with
caution.
