Items | Standard |
Assay | ≥93.0% |
Loss on drying | ≤1.0% |
Sulfate | ≤0.2% |
Arsenic | ≤5ppm |
Ferric salt | ≤2.0% |
Lead | ≤0.001% |
Heavy metal | ≤50ppm |
Organic volatile impurities | qualified |
Chromium | ≤200ppm |
Cadmium | ≤10ppm |
Mercury | ≤1.0ppm |
Nickel | ≤200ppm |
Zinc | ≤500ppm |