S. Himeno et al., DIRECT SPECTROPHOTOMETRIC DETERMINATION OF PHOSPHONATE AND DIPHOSPHATE IONS BASED ON THE FORMATION OF HETEROPOLY BLUE COMPLEXES, Analytical sciences, 13(3), 1997, pp. 369-372
A simple spectrophotometric method is proposed for the direct determin
ation of PHO32- and P2O74- ions. In acidic solutions containing 50%(v/
v) CH3COCH3, the Mo(VI)-Mo(V) reagent reacts directly with PHO32- and
P2O74- ions to form the respective heteropoly blues. The amounts of mi
xed-valence blue species thus formed depended linearly on the PHO32- a
nd P2O74- concentrations in the ranges 1x10(-5) -1x10(-3) M and 2x10(-
5) -2x10(-4) M, respectively. Interferences from foreign ions are also
discussed.