L-Tryptophan, Feed Additive, Amino Acid, Feed Grade/Amino Acid, Appearance:White crystals or pale yellow crystalline powder L-Tryptophan ... /Feed Grade/Amino Acid,CAS NO: 73-22-3,Certificate of Analysis:ItemStandard(Q ... )≥98%98.57%Specific rotation-29.0°—-33.0°-31.04° Chloride≤0.03%0.004% Sulfate≤0.03%0. ... ≤0.5%0.10% L-Tryptophan, Feed Additive, Amino Acid