Abstract
It was discussed about the sodium salt of FAD in this paper. Sodium was estimated colorimetrically as the zinc uranyl acetate complex and also titrimetrically as the sodium chloride isolated with Amberlite IR-120. Hydrate was determined with Karl-Fischer method. The stoichiometric point of the sodium salt of FAD as determined by the potentiometric titration curve was about 6. The curve presented clearly shows that two moles of sodium hydroxide united with one mole of FAD resulting in the break of the curve at pH 6. The dissociation constants, K_1 and K_2,were 7.6×10^<-4> and 6.0×10^<-5>, respectively. Inspection of the data shows that the sodium salt of FAD, when dried in vacuum desiccator over phosphorus pentoxide at room temperature, is FAD disodium salt dihydrate (C_<27>H_<31>N_9O_<15>P_2.Na_2.2H_2O).
