性能描述

assay    ≥99.5% (NT) 
optical activity    [α]20/D −39±1°, c = 2% in H2O 
impurities    insoluble matter, passes filter test 
   ≤0.5% foreign amino acids 
ign. residue    ≤0.1% (as SO4) 
loss    ≤0.5% loss on drying, 110 °C 
pH    7.0-8.0 (25 °C, 0.1 M in H2O) 
mp    282 °C (dec.)(lit.) 
   ~285 °C (dec.) 
solubility    H2O: soluble0.1 M at 20 °C, clear, colorless 

Biochem/physiol Actions
Precursor of histamine by action of histidine decarboxylase.
Amino acid spacing in isotachophoresis on polyacrylamide gels - a critical evaluation; Prevents circular DNA strand cleavage in a xanthine-xanthine oxidase system; Growth requirement of various microorganisms.

性       状： 无色针状或片状结晶。为天然的组氨酸。味甜。对空气敏感。在227℃时软化，287℃分解。水中溶解度为41.6 g/l (25°C)，极微溶于乙醇，不溶于乙醚、丙酮等有机溶剂，溶于无机酸。
熔点:  282 °C 
[a]20/D:  12.4° (c=11,6N HCl)  
质量标准： ≥99.5% (NT):

外观Appearance                          白色结晶粉末，光照下会有颜色
红外光谱鉴别Infrared spectrometry       和对照品匹配
含量Assay                               >99% (以无水物计)
干燥失重Loss on drying                  <0.2 % (105°C, 3 hrs)
重金属Heavy metals (as Pb)              <10 ppm
硫酸盐灰分Sulfated ash                  <0.1 %
比旋度Specific rotation [a]20/D         +12° ～ +12.8°(c=11, 6 N HCl) 
NH4                                     < 100 ppm
Cl                                      < 100 ppm
SO4                                     < 100 ppm
Fe                                      < 10 ppm
透光率Transmittance                     >98 % (c=5, H2O, 430 nm) 1 cm cell
pH                                      7 - 8.5 (2% 水溶液)
其它氨基酸Foreign amino acids           <0.3 % (TLC)

EP, USP ，非动物源,用于细胞培养：

来源ORIGIN                              from non-animal source
外观Appearance                          白色至类白色结晶粉末
红外鉴别IDENTIFICATION BY IR            和参考标准一致
水溶解试验solubility in water           无色溶液 0.5G/10ML水
比旋光度Specific rotation [a]20/D       +12.0°～ +12.8°(20°C /EP)
                                        +12.6 ～ +14.0 DEG (25°C /USP)
                                        C = 11 , 6M HCL
氯Chloride                              ≤0.020%
铵Ammonium                              ≤0.02%
硫酸根Sulfate                           ≤0.020%
铁Iron                                  ≤ PPM
重金属Heavy metals                      ≤10 PPM
砷Arsenic                               ≤ 1 PPM
干燥损失Loss on drying                  ≤0.20%
灼烧残渣Residue on ignition             ≤0.10%
茚三酮阳性物质Ninhydrin-positive Substances(OTHER AMINO ACIDS)
                                        CONFORMS
溶剂残渣Residual solvents               MEETS THE REQUIREMENTS
PH TEST                                 7.0 ～ 8.5 (2% IN WATER)
含量ASSAY (DRY BASIS)                   98.5 ～ 101.0%
内毒素Endotoxin                         ≤ 1 EU/MG
细胞培养测试Cell culture test           PASS