Product Description Histidine is a semi-essential amino acid (children should obtain it from food) needed in humans for growth and tissue repair, Histidine is important for maintenance of myelin sheaths that protect nerve cells and is metabolized to the neurotransmitter histamine. Histamines play many roles in immunity, gastric secretion, and sexual functions. Histidine is also required for blood cell manufacture and protects tissues against damage caused by radiation and heavy metals. BASIC ANALYSIS Analysis Description Test Method Assay (dry basis) 99.0～101.0% HPLC Loss on drying Not More Than 0.20% Dryer Residue on ignition Not More Than 0.10% Ph. Eur. Related substances Not More Than 0.5% Ph. Eur. Endotoxin* Less Than 6.0 EU/g Ph. Eur. State of solution(Transmittance) Not Less Than 98.0% Ph. Eur. PH 7.0～8.5  Ph. Eur. Specific rotation[α]20D +12.0～+12.8°  Ph. Eur. Specific rotation[α]25D +12.6～+14.0°  Ph. Eur. Ammonium (NH4) Not More Than 0.020%   Ph. Eur. Chloride (Cl) Not More Than 0.020%  Ph. Eur. Sulfate (SO4) Not More Than 0.020%  Ph. Eur. Iron (Fe) Not More Than 10 ppm ICP-MS/AOAC 993.14 Arsenic (As) < 1 ppm ICP-MS/AOAC 993.14 Cadmium (Cd) < 2 ppm ICP-MS/AOAC 993.14 Heavy metals (Pb) Not More Than 10 ppm ICP-MS/AOAC 993.14 Mercury (Hg) < 0.5 ppm ICP-MS/AOAC 993.14 Microbial Analysis Total Plate Count < 3,000 cfu/g AOAC 990.12 Total Yeast & Mold < 300 cfu/g AOAC 997.02 E. Coli < 10 cfu/g AOAC 991.14 Coliforms < 10 cfu/g AOAC 991.14 Salmonella Negative ELFA-AOAC Staphylococcus < 10 cfu/g AOAC 2003.07 Function L-histidine (HIS) is an essential amino acid with unique roles in proton buffering, metal ion chelation, scavenging of reactive oxygen and nitrogen species, erythropoiesis, and the histaminergic system.