Sigma-Aldrich L-Methionine For Biochemistry

for biochemistry

L-Methionine for biochemistry. CAS 63-68-3, pH 5 - 7 (10 g/L, H₂O, 20 °C).

Assay (perchloric acid titration, calculated on dried substance)≥ 99.0 %Identity (IR-spectrum)passes testAppearancewhite or almost white, crystalline powder or colorless crystalsAppearance of solution (0.5 mol/L, hydrochloric acid 1 mol/L)clear and colorlessSpec. rotation (α 20/D, 50 g/L, hydrochloric acid 1 mol/L, calc. on dried substance)+22.5 to +23.5UV-Absorption (260 nm, 0.5 mol/L, 1 cm, hydrochloric acid 1 mol/L)≤ 0.50UV-Absorption (280 nm, 0.5 mol/L, 1 cm, hydrochloric acid 1 mol/L)≤ 0.20Chloride (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≤ 0.3 %Other ninhydrine positive substances≤ 0.1 %Loss on drying (105 °C; 3 H)≤ 0.3 %