... crystalline powder1,Formula: Na2HPO4; Na2HPO4·nH2O (n = 2,7 or 12)2,Formula wt: anhydrous 141.96; Formula wt, dihydrate 177 ... 5.0%;2,Dihydrate:18.0%-22.0%. (120°C,4h)1,Anhydrous ≤5.0%,2,Dihydrate ≤22.0%3,Heptahydrate ≤50.0%4,Dodecahydrate ≤61.0%( ... 40°C,3h then 105°C,5h))As,≤%0.00030.0003Cadmium ≤%--0.0001Mercury ≤%--0.0001 disodium phosphate