Assay (acidmetric)......99.5-100.2%

pH (cold saturated solution) 3.4-3.7

Cl...................................0.02% max

C2O4..............................0.05% max

SO4................................0.008% max

H.M (as Pb).....................0.001% max

NH4................................0.005% max

As...................................0.0001% max

Ba...................................0.15% max

Pb...................................0.001% max

Ca...................................0.01% max

Fe....................................0.002% max

Cu...................................0.0025% max

Zn....................................0.0025% max

Loss on drying (105deg)......0.5% max

Formula: C4H5KO6

Mwt: 188.18

CAS: 868-14-4