Assay (acidimetric, calculated on dried substance): 99.0 - 101.0 %

Identity (IR-spectrum): passes test

Appearance: white to almost white, fine-crystalline powder or colorless crystals

Appearance of solution (50 g/l; water): clear and colorless

Spec. rotation (α 20/D, 110 g/l, hydrochloric acid 120 g/l, calc. on dried substance): +11.4 to +12.4

Chloride (Cl): ≤ 200 ppm

Sulfate (SO₄): ≤ 200 ppm

Heavy metals (as Pb): ≤ 10 ppm

As (Arsenic): ≤ 5 ppm

Ca (Calcium): ≤ 10 ppm

Co (Cobalt): ≤ 5 ppm

Fe (Iron): ≤ 5 ppm

K (Potassium): ≤ 5 ppm

Mg (Magnesium): ≤ 5 ppm

Na (Sodium): ≤ 100 ppm

Zn (Zinc): ≤ 5 ppm

Ninhydrin-positive substances (LC)(any ninhydrin-positive impurity): ≤ 0.2 %

Ninhydrin-positive substances (LC) (ammonium (570 nm)): ≤ 0.02 %

Ninhydrin-positive substances (LC)(total impurities): ≤ 0.5 %

Loss on drying (105 °C; 3 h): ≤ 0.2 %