Thiamine Hydrochloride

Thiamine Hydrochloride
Vitamin B1 Hydrochloride
C12H17ClN4OSHCl Mol. Wt. 337.27
3-(4-amino-2-methylpyridine-5-ylmethyl)-5-(2-hydroxyethyl)-4-methylthiazolium
chloride monohydrochloride 67-03-8
Content Thiamine Hydrochloride, calculated on the anhydrous basis, contains
98.0102.0% of thiamine hydrochloride (C12H17ClN4OSHCl).
Description Thiamine Hydrochloride occurs as white to yellowish-white, fine
crystals or crystalline powder. It is odorless or has a slight, characteristic odor.
Identification (1) To 1 ml of Thiamine Hydrochloride solution (1 500), add 1
ml of lead acetate TS and 1 ml of sodium hydroxide solution (1 10). The color of the
solution changes to yellow. Warm on a water bath. It changes to brown. Then allow to
stand. A black-brown precipitate is formed.
(2) To 5 ml of Thiamine Hydrochloride solution (1 500), add 2.5 ml of sodium
hydroxide solution (1 25) and 0.5 ml of freshly prepared potassium ferricyanide
solution (1 10), then add 5 ml of isobutyl alcohol, shake vigorously for 2 minutes,
and allow to stand. Observe under ultraviolet light. The isobutyl alcohol layer emits a
blue-purple fluorescence. The fluorescence disappears on acidifying the solution. It
reappears on making the solution alkaline.
(3) Thiamine Hydrochloride responds to all tests for Chloride as described in the
Qualitative Tests .
Purity (1) Clarity and color of solution Weigh 1.0 g of Thiamine Hydrochloride,
and dissolve in water to make 10 ml. The solution is clear, and its color is not darker
than that of the solution prepared as follows: Measure 1.5 ml of 1/60 mol/l potassium
dichromate solution, and add water to make 1,000 ml.
(2) pH 2.73.4 (1.0 g, water 100 ml).
(3) Sulfate Not more than 0.011% as SO4 (1.5 g Control solution 0.005 mol/l
sulfuric acid 0.35 ml).

(4) Heavy metals Not more than 20µg/g as Pb (1.0 g, Method 1, Control
solution Lead Standard Solution 2.0 ml).
Water Content Not more than 5.0% (0.5 g direct titration).
Residue on Ignition Not more than 0.20%.
Assay Weigh accurately about 0.1 g each of Thiamine Hydrochloride and
Thiamine Hydrochloride Reference Standard (measure previously the water content in
the same manner as for Thiamine Hydrochloride), dissolve each in the mobile phase to
make exactly 50 ml. Measure each solution exactly 10 ml, add exactly 5 ml of a methyl
benzoatemethanol solution, (1 50) to each solution, and add the mobile phase to
make exactly 50 ml. Use these solutions as the test solution and the standard solution,
respectively. Measure 10 µl each of these solutions, and perform Liquid
Chromatography under the conditions given below. Calculate the ratio of the peak area
of thiamine to the peak area of methyl benzoate for each solution, and express as Qt
and Qs, respectively. Calculate the content by the formula
Content of thiamine hydrochloride (C12H17ClN4OSHCl)
Weight(g) of Thiamine Hydrochloride Reference
Standard calculated on the anhydrous basis
Qt
= × × 100(%) .
Weight(g) of the sample calculated on the anhydrous basis Q
s
Operating Conditions
Detector: Detector for absorbances in the ultraviolet range (determination
wavelength: 254 nm).
Column packing material: 5- to 10-µm octadecylsilanized silica gel.
Column: Stainless steel tube about 4 mm in internal diameter and 1530
cm in length.
Column temperature: constant temperature about 25.
Mobile phase: Dissolve 1.1 g sodium octanesulfonate in 1,000 ml of diluted
acetic acid (1100). To 600 ml of this solution, add 400 ml of a mixture of
methanol-acetonitrile (3:2).
Flow rate: Adjust the flow rate so that the retention time of thiamine is about
12 minutes.