Property: White crystalline granular or powder Specification: Item Top Grade First Grade Qualified Grade Purity%,≥ 98.5 98.0 97.5 Loss on drying,%,≤ 0.5 0.5 0.5 PH(1%solution) 2.8 Residue on ignition,%, ≤ 0.1 0.1 0.1