Items Standard Appearance White powder Specific Rotation [20/D] (C=4 in methanol) -22.0 to -26.0 State of Solution (Transmittance) Not less than 95.0% Heavy Metals (Pb) Not more than 20 PPM Arsenic (As2O3) Not more than 2 PPM Loss on Drying Not more than 0.50% Residue on Ignition Not more than 0.3% Assay 97.5% to 102.5%