  IceTop, the surface array of IceCube, measures air showers from cosmic rays
within the energy range of 1 PeV to a few EeV and a zenith angle range of up to
$\approx$ 36$^\circ$. This detector array can also measure air showers arriving
at larger zenith angles at energies above 20 PeV. Air showers from lighter
primaries arriving at the array will produce fewer muons when compared to
heavier cosmic-ray primaries. A discrimination of these muons from the
electromagnetic component in the shower can therefore allow a measurement of
the primary mass. A study to discriminate muons using Monte-Carlo air showers
of energies 20-100 PeV and within the zenith angular range of
45$^\circ$-60$^\circ$ will be presented. The discrimination is done using
charge and time-based cuts which allows us to select muon-like signals in each
shower. The methodology of this analysis, which aims at categorizing the
measured air showers as light or heavy on an event-by-event basis, will be
discussed.
