where ma is the mass of Mo co-precipitated, mg;
4.382 is its conversion factor to MoO2L2 (L
stands for the TDTC anion here), i.e. 420.453/
95.94; mb is the mass of V co-precipitated, mg;
7.390 is its conversion factor to VO(OH)L2, i.e.
376.463/50.942.
Once m1 and m2 are known, ma and mb can be
determined as follows. Dissolve the precipitate in
aqua regia, dilute to a definite volume and take
aliquots for determining Mo by photometry with
thiocyanate and V by oxidimetry or 2,2%-
iminodibenzoic acid method [8], respectively