Sigma-Aldrich L-Isoleucine For Biochemistry

Assay (perchloric acid titration, calculated on dried substance): ≥ 99.0 %
Identity (IR-spectrum): passes test
Appearance: white to almost white, crystalline powder or flakes
Appearance of solution (1 mol/L, hydrochloric acid 1 mol/L): clear and colorless
Spec. rotation (α 20/D, 50 g/L, hydrochloric acid 1 mol/L, calc. on dried substance): +36.2 to +37.2
UV-Absorption (260 nm, 1 mol/L, 1 cm, hydrochloric acid 1 mol/L): ≤ 0.10
UV-Absorption (280 nm, 1 mol/L, 1 cm, hydrochloric acid 1 mol/L): ≤ 0.10
Chloride (Cl): ≤ 0.02 %
Sulfate (SO₄): ≤ 0.01 %
Heavy metals (as Pb): ≤ 0.001 %
As (Arsenic): ≤ 0.0005 %
Ca (Calcium): ≤ 0.001 %
Co (Cobalt): ≤ 0.0005 %
Fe (Iron): ≤ 0.0005 %
K (Potassium): ≤ 0.0005 %
mg (Magnesium): ≤ 0.0005 %
Na (Sodium): ≤ 0.005 %
NH₄ (Ammonium): ≤ 0.01 %
Zn (Zinc): ≤ 0.0005 %
Foreign amino acids: ≤ 0.5 %
Other ninhydrine positive substances: ≤ 0.1 %
Loss on drying (105 °C; 3 H): ≤ 0.3 %