... May have complex reaction with the potassium pyrophosphate, becoming water-soluble pyrophosphoric acid copper potassium complex salt.Relative molecular mass:301 ... carburization accessories. Specification: ItemsSpecial GradeAssay (Cu) ≥34.0Insoluble Matter in Potassium Pyrophosphate,% ≤0.1Sodium (Na) ,% ≤0.5Lead (Pb) ,% ≤0.003Iron ( ... 0.0003Chloride (Cl) ,% ≤0.01Zinc (Zn) ,% ≤0.005 Copper Pyrophosphate