Bulk amino acid powder L-Tryptophan Description: Tryptophan is one of eight essential amino acids - basically meaning that the body cannot produce tryptophan itself, it must be obtained through diet. Tryptophan is best known as a precursor of serotonin . Tryptophan can be found in foods like meat, fish and dairy products. Feed grade L-Tryptophan Specification: ItemSpecification AppearanceLight yellow to white crystalline powder Assay ≥98.5% Loss on drying ≤0.5% Residue on ignition ≤0.5% Specific rotation-29.0º~ -32.8º PH5.0~7.0 As ≤2mg/kg Pb ≤5mg/kg Cd ≤2mg/kg Hg ≤0.1mg/kg FAQ Q: Are you manufacturer ? A: We are manufacturer for amino acids. Q: Do you provide FREE samples ? A: Yes, we could offer the sample for free but freight cost should be bear by yourself. Q: What is your terms of payment ? A: TT or LC. Q: What’s your delivery time? A: Usually 14 days after receipt of the deposit but also depends on your quantity.wholesale L-tryptophan website:http://www.blrhbio.com/tryptophan/l-tryptophan/