Attempts were made to eliminate interferences
from Mo and V, but failed. Thus, we can not help
taking another approach: to precipitate them altogether,
determine their co-precipitated amounts
and make corrections for them (Eq. (2)). Fortunately,
their presence or absence can be readily
detected by the naked eye: in their absence the
precipitate is pure white; while in their presence it
is colored (yellow if V is present and scarlet if Mo
present). Their determinations are also an easy
matter. Indeed, a clear-cut separation of Mo and
V from Sn seems very much difficult, if not impossible,
to incorporate conveniently in the proposed
method