Histamine Dihydrochloride CAS 56-92-8 Assay 98.5~101.0% (Titration) Factory

Histamine Dihydrochloride (CAS: 56-92-8) EP9.0 VolumeⅡTest Method
DEFINITION
Histamine dihydrochloride contains not less than 98.5 percent and not more than the equivalent of 101.0 percent of 2-(1H-imidazol-4-yl)ethan-1-amine dihydrochloride, calculated with reference to the dried substance.
CHARACTERS
A white or almost white, crystalline powder or colourless crystals, hygroscopic, very soluble in water, soluble in alcohol.
IDENTIFICATION
First identification: A, D.
Second identification: B, C, D
A. Examine by infrared absorption spectrophotometry (2.2.24), comparing with the spectrum obtained with histamine dihydrochloride CRS. Examine as discs prepared using 1 mg of substance.
B. Examine the chromatograms obtained in the test for histidine. The principal spot in the chromatogram obtained with test solution (b) is similar in position, colour and size to the principal spot in the chromatogram obtained with reference solution (a).
C. Dissolve 0.1 g in 7 mL of water R and add 3 mL of a 200 g/L solution of sodium hydroxide R. Dissolve 50mg of sulfanilic acid R in a mixture of 0.1 mL of hydrochloric acid R and 10 mL of water R and add 0.1 mL of sodium nitrite solution R. Add the second solution to the first and mix. A red colour is produced.
D. It gives reaction (a) of chlorides (2.3.1).
TESTS
Solution S. Dissolve 0.5g in carbon dioxide-free water R prepared from distilled water R and dilute to 10 mL with the same solvent.
Appearance of solution. Solution S is clear (2.2.1) and not more intensely coloured than reference solution Y7 (2.2.2,Method II).
pH (2.2.3). The pH of solution S is 2.85 to 3.60.
Histidine. Examine by thin-layer chromatography (2.2.27), using a TLC silica gel G plate R.
Test solution (a). Dissolve 0.5g of the substance to be examined in water R and dilute to 10 mL with the same solvent.
Test solution (b). Dilute 2 mL of test solution (a) to 10 mL with water R.
Reference solution (a). Dissolve 0.1 g of histamine dihydrochloride CRS in water R and dilute to 10 mL with the same solvent.
Reference solution (b). Dissolve 50 mg of histidine monohydrochloride R inwater R and dilute to 100 mL with the same solvent.
Reference solution (c). Mix 1 mL of test solution (a) and 1 mL of reference solution (b).
Apply to the plate 1 μL of test solution (a), 1 μL of test solution (b), 1 μL of reference solution (a), 1 μL of reference solution (b) and 2 μL of reference solution (c). Develop over a path of 15cm using a mixture of 5volumes of concentrated ammonia R, 20 volumes of water R and 75 volumes of acetonitrile R. Dry the plate in a current of air. Repeat the development in the same direction, dry the plate in a curren of air and spray with ninhydrin solution R1. Heat the plate at 110°C for 10 min. Any spot corresponding to histidine in the chromatogram obtained with test solution (a) is not more intense than the spot in the chromatogram obtained with reference solution (b) (1 per cent). The test is not valid unless the chromatogram obtained with reference solution (c) shows 2 clearly separated spots.
Sulfates (2.4.13). 3mL of solution S diluted to 15 mL with distilled water R complies with the limit test for sulfates (0.1 percent).
Loss on drying (2.2.32). Not more than 0.5 percent, determined on 0.20 g by drying in an oven at 105 °C.
Sulfated ash (2.4.14). Not more than 0.1 percent, determined on 0.5 g.
ASSAY
Dissolve 0.080 g in a mixture of 5.0 mL of 0.01 M hydrochloric acid and 50 mL of alcohol R. Carry out a potentiometric titration (2.2.20), using0.1 M sodium hydroxide. Read the volume added between the first and third points of inflexion.
1mL of 0.1 M sodium hydroxideis equivalent to 9.203 mg of C5H11Cl2N3.
STORAGE
Store in an airtight container, protected from light.