Journal of Siberian Federal University. Chemistry: Titrimetric Determination of Phosphorus in Aqueous Solutions of Mo-V-phosphoric Heteropoly Acids and Catalysts Based on Them

Journal of Siberian Federal University. Chemistry / Titrimetric Determination of Phosphorus in Aqueous Solutions of Mo-V-phosphoric Heteropoly Acids and Catalysts Based on Them

Issue: Journal of Siberian Federal University. Chemistry. 2010 3 (1)
Authors: Odyakov, Viktor F.; Zhizhina, Elena G.
Contact information: Odyakov, Viktor F. : G.K. Boreskov Institute of Catalysis. Siberian Branch of RAS , 5 Prospekt Akad. Lavrentieva, Novosibirsk, 630090 Russia , e-mail: ; Zhizhina, Elena G. : G.K. Boreskov Institute of Catalysis. Siberian Branch of RAS , 5 Prospekt Akad. Lavrentieva, Novosibirsk, 630090 Russia
Keywords: heteropoly acids; precipitation of phosphorus; determination of phosphorus; potentiometric titration
Abstract: The analyzed aqueous solution of Mo-V-phosphoric heteropoly acid is reduced by d,l-tartaric acid (d,l-H₂Tart) at room temperature. d,l-H₂Tart reduces only vanadium(V) to vanadium(IV). The obtained solution is neutralized by ammonia, then the Mg(NO₃)₂ solution is added to it giving the NH₄ [MgPO₄]•xH₂O precipitate. This precipitate is washed by the triple buffer NH₄NO₃ + NH₃ + (NH₄)₃HCit solution containing citrate, then by the puffer NH₄NO₃ + NH₃ solution without citrate. Next the precipitate is dissolved in 1,0 M HNO₃. The obtained solution is titrated by 0,100 M lead(II) nitrate solution in the acetate buffer in the presence of Clˉ-ions using the Pb²⁺-selective electrode. In the course of the titration, the Pb₅Cl(PO₄)₃ precipitate is formed.
Pages: 20-26
Paper at repository of SibFU: https://elib.sfu-kras.ru/handle/2311/1755