Assay (acidimetric, Na₂CO₃): 36.7 - 40.0 %

Assay (acidimetric): 99.0 - 102.0 %

Identity: passes test

Appearance of solution: passes test

Alkali hydroxides and Alkali hydrogen carbonates: passes test

Chloride (Cl): ≤ 0.0005 %

Sulfate (SO₄): ≤ 0.003 %

Phosphate and Silicate (as SiO₂): ≤ 0.002 %

Total sulfur (as SO₄): ≤ 0.003 %

Total nitrogen (N): ≤ 0.0005 %

Heavy metals (as Pb): ≤ 0.0005 %

Al (Aluminium): ≤ 0.0005 %

As (Arsenic): ≤ 0.0002 %

Ca (Calcium): ≤ 0.002 %

Fe (Iron): ≤ 0.0002 %

K (Potassium): ≤ 0.005 %

Mg (Magnesium): ≤ 0.0002 %

Corresponds to ISO, Reag. Ph Eur