SU1684660A1 - Method of quantitative determination of thiamine bromide - Google Patents

Abstract

The invention relates to analytical chemistry, in particular the quantitative determination of thiamine bromide, which can be used to control its production. The goal is to increase the selectivity and sensitivity of the analysis. The latter is carried out by titrating the sample, taken in the form of an aqueous solution, with a solution of sodium tungstate in the presence of 3, M solution of sodium hydro- or dihydrophosphate at pH 1-2, created by HCI or. These conditions provide a detection sensitivity of 5, g / ml with a relative error of 1.2% versus 5-10 cases. 11 tab. -4 g / ml and 1% in the known

Description

The invention relates to analytical chemistry, in particular to methods for quantifying thiamine bromide, and can be used by control and analytical laboratories.

The aim of the invention is to increase the selectivity and sensitivity of the determination of thiamine bromide.

PRI me R 1. The exact mass (about 0.02 g) of thiamine bromide is placed in a 100 ml measuring flask and the contents of the flask are brought to the mark with water. 1 ml of the prepared solution is placed in the titration beaker, 2 ml of 0.01 M sodium hydrogen phosphate (dihydrogen phosphate) solution and 1 M hydrochloric (sulfuric) acid are added to pH 1-2, the total volume of the analyzed mixture is adjusted to 30 ml with water. The cups are placed in the V-titrator T-107 and titrated with a magnetic stirrer switched on with a 0.005 M solution of sodium tungsten mat with a blue light filter, added the first portion

titrant 0.6 ml. After 3 minutes, instrument readings are recorded. Subsequent addition of the titrant is carried out at 0.1 ml after 2 minutes. The reaction consumes about 1 ml of a standard solution of sodium tungstate.

According to the data obtained, the titration curves are constructed in the coordinates tf (V) where V is the volume of the titrant solution, ml;

 t is the amount of light transmission,%

The equivalence point is found graphically by extrapolation of the two straight lines of the titration curve.

The concentration of the test substance in percent is determined by the volumetric titration formulas. 1 ml of 0.005 M solution of sodium tungstate corresponds to 00002176 g of thiamine bromide

The statistical processing of the results of the analysis of thiamine bromide is given in Table. one.

WITH

WITH

about

00

B os

oh oh

The relative determination error by the proposed method is equal to ± 1.20%. The quantitative determination of thiamine bromide with this relative error is carried out at its content in the sample of 0.17-0.26 mg (see Table 1).

Experimental data showed that, under optimal conditions, thiamine bromide can be quantitatively determined by the ratio of concentrations of thiamine bromide and potassium iodide, as well as sodium chloride and ascorbic acid (1: 100), nicotinic acid, pyridoxine g / x, pyrazolones (1 :50).

The research results are summarized in table. 2-7.

Thus, from table. 2-7, thiamine bromide under optimal conditions can be determined in the presence of the ingredients listed above with a relative error not exceeding + 1.24%.

The method can be used to quantify thiamine bromide in the following mixtures, g:

PRI me R 2.

Thiamine bromide0.02

To-you nicotinic0,02

Solution of sodium chloride

0.45% 100ml

P-ra Riboflavin 0.01% 100 ml

Thiamine bromide0.05

K-ascorbic 0.3

Cali iodide 3.0

Thiamine bromide0.05

K-ascorbic1,0

Pyridoxine g / x0.05

Riboflavin0.05

Glucose1.0

Thiamine bromide0.02

Amidopyrine 0.2

K-you ascorbic 0.2

Cali iodide

For the analysis, proceed as follows: 1 ml (mixture 1) or 0.5 ml (mixture 2) of the test dosage form is placed in a titration beaker, 2 ml of a 0.01 M hydrotreated solution (di

hydrochloride sodium phosphate, hydrochloric (sulfuric) acid create a pH of 1-2, bring the volume of the analyzed mixture to 30 ml with distilled water and titrate with the magnetic stirrer turned on and the blue light filter, similarly to example 1.

When analyzing thiamine bromide in mixtures 3 and 4, 0.05 g of the dosage form is dissolved (mixture 3 when heated) in a 25 ml volumetric flask, cooled, brought to the mark with water. Put 7 ml of a mixture of 3 and 4 ml of a mixture of 4 of the resulting solution into a titration cup and then proceed as in the analysis of mixtures 1 and 2.

The results of the analysis of thiamine bromide in mixtures x 1, 2, 3, 4 are given in table. eight.

The content of thiamine bromide, found by the proposed method, is within the limits of tolerances.

In the course of the research, optimal conditions were determined for the analysis of thiamine bro: mida.

In tab. 10, 9 presents the results of the analysis of vitamin B beyond the optimum 5 phosphate levels and beyond the optimum pH of the medium. It is established that the error of quantitative determination increases to + 3.86%.

In tab. 11 presents the comparative 0 data of the results of the analysis of thiamine bromide by the proposed and known methods.

From tab. 11 that the inventive method makes it possible to increase the sensitivity of the determination of thiamine bromide by a factor of 100 and

0

five

reduce the costs of the substance being determined by 2.5 times.

Claims (1)

The invention of the method for quantitative determination of thiamine bromide by titrating an aqueous solution of an analyzed sample with an inorganic reagent, characterized in that, in order to increase the selectivity and popularity of the determination, sodium tungstate solution is used as an inorganic reagent and titration is carried out in the presence of 3.3-10-17 10 4 M solution of sodium hydro- or dihydrophosphate at pH 1-2, created by hydrochloric or sulfuric acid Table 1 Table 3 The results of the analysis of thiamine bromide in the presence of potassium iodide (CTg.: CRa 1: 100) Table 5 The results of the analysis of thiamine bromide in the presence of nicotinic acid (CTg-: C Nick. k-tia 1:50) Table 6 The results of the analysis of thiamine bromide in the presence of pyridoxine g / x (CTg: LNG, 1:50) Table 7 The results of the analysis of thiamine bromide in the presence of amidopyrine (CTg: Samid 1:50) Table Quantitative determination of thiamine bromide with phosphate content outside the interval of 3.3-10 M. Phosphate content is less than 3.3-10 M. Quantitative determination of thiamine bromide at pH 3.5 and 0.5 Table 10 Thiamine Bromide Analysis Continuation of table 10 Table 11