Features Specifications:Sell L-threonin  L-threonin1. L-threonine(dry basis): 98.5% Min Specific Rotation[a]20D : -26.0° -29°  PH(0.01g/ml): 5.0-6.5  Loss on drying : 1.00% Max  Residue on ignition : 0.30% Max  Heavy Metals: 0.002% Max Arsenic(As2O3): 0.0002% Max