SU1541494A1 - Method of quantitative determination of ephedrine hydrocyclone - Google Patents

Abstract

The invention relates to analytical chemistry, in particular the quantitative determination of ephedrine hydrochloride, can be used in the control of the corresponding production. The goal is to reduce the analysis time. The latter is carried out by treating the sample with potassium periodite in a bicarbonate medium, followed by reduction with manganese acetate (2+) in the presence of dipicolinic acid and spectrophotometry the solution. These conditions shorten the analysis time by 6 times (for 25 minutes) while ensuring the possibility of spectrophotometry in the visible region of the spectrum (at 504 nm) and eliminating the interfering influence of substances that absorb ultraviolet light at 281 nm. 5 tab.

Description

The invention relates to a method for the quantitative determination of ephedrine hydrochloride and may find application in control and analytical laboratories.

The purpose of the invention is to reduce the analysis time.

Example K Quantitative determination of ephedrine hydrochloride in the preparation.

0.15 g (exact weight) of the test sample is transferred into a 200 ml volumetric flask, dissolved in distilled water and made up to the mark.

In a volumetric flask with a capacity of 50 ml, transfer 5 ml of the test solution, add to it 3 ml of sodium hydrogencarbonate solution with a Mansoe concentration of 0.2 mol / l and 4.0 ml of potassium periodate solution with a concentration C (0.01 mol / l, thoroughly mix the contents of the flask and oxidize at room temperature for 15 minutes Then add 0.7 ml of a solution of sulfuric acid with a concentration of Cg50 + 0.05 mol / l, 10 ml of a solution of dipicolinic acid with a concentration of c-HjN04 0.025 mol / l and 2.5 ml of a solution of manganese acetate (II) with a concentration of C "n (cnscoou ° . ° 4 "" IL / L. After 5 minutes, the contents of the flask are diluted with distilled water to the mark, mixed, and the light absorption of the resulting solution is measured by spectroscopy.

4 4

with

-U

photometer in cuvettes with a layer thickness of 1 cm at a wavelength of 504 them.

In parallel, a blank experiment was carried out using the same procedure (instead of a solution of ephedrine hydrochloride, water was taken).

The mass fraction (in percent) of ephedrine hydrochloride in the preparation is calculated by the formula

her

A ,, - Ah1 | C “K-rzo z5fei0J j.i..JLАо m (c, 0H15№ her) Yumalnaya for indirect determination of the periodate ion. With more pH, the color of the solution is chow. This is due to the hydrolysis of manganese (II).

de

A0 is the absorption of the plant of idle experience; A „- light absorption isl

the solution to follow; C0 KJO — initial molar concentration of potassium period in the final volume of the analyzed solution, mol / l; molar mass of ephedrine hydrochloride, g / mol;

r u ml of it weight ephedri

on hydrochloride, g

In tab. 1 shows the results of spectrophotometric determination of ephedrine hydrochloride (MS, 201.696 g / mol;

C10 H (iNO HCI

 About K304

 8.0-1 mol / l; spectro -

About f- JU4,

otometer Bpecord M 40).

In preliminary experiments, it was established that by mixing a solution of potassium perganate with a solution of manganese acetate (II) in molar ratios of 1: 4 or with an excess of manganese acetate in the presence of dipicolinic acid in a weakly acidic medium (pH 2-3), the color of the permanganate ion quickly disappears and the solution becomes a cherry-red color.

The dependence of the absorption of the solution obtained by the oxidation of manganese (II) compounds with dipicolinic acid with potassium periodate on the pH of the medium is presented in Table. 2 (s (CH3Coo) g - 2.0 Cc7n5 04 5.0-10; C0ioo + 7.0 104 mol / l; T 293 K; 1 1 cm; A 504 nm; spectrophotometer Spec or d M 40).

From board 2 it can be seen that the range of pH values 2.3-4.0 is the opto (A0-Ax) -C omo VK-10 to

where VR is the final volume of the analyzed solution, l "

Ichnso3

Ao m (c, 0H15 # nee) is minimal for the indirect determination of the periodate ion. At higher pH values, the color of the solution is unstable. This is due to the hydrolysis of manganese (II) compounds.

In the manganese (II) –picolinic acid – potassium periodate system, we will execute the basic law of absorption. To quantify ephedrine hydrochloride using periodate oxidation, its stoichiometry is examined as follows. In a volumetric flask with a capacity of 50 ml were transferred 5 ml of a solution containing 15 μmol of ephedrine hydrochloride, 3 ml of sodium carbonate with a concentration of 0.2 mol / l.

In tab. 3 pumped the dependence of the light absorption of the solution complex

0 manganese (II) with dipicolinic acid from the concentration of potassium periodate (CWVn (CH3coo) 3.6 -1СГ3; CtlH5N04 1.0-10 mol / l; pH - (2.85; T 293 K; 1 1 cm; D

5 504 nm; Spectrophotometer Specord M 40)

Take 4 ml of potassium periodate solution with a CaO4 C concentration of 0.01 mol / l, mix well

0 and oxidized at room temperature. After a certain period of time from the start of the oxidation reaction, the analysis is carried out as in the determination of ephedrine hydrochloride 5 in the preparation. In parallel, a blank experiment was carried out using the same procedure (instead of a solution of ephedrine hydrochloride, water was taken).

Amount of potassium periodate

0 (in micromol) consumed in the reaction with the amount of ephedrine hydrochloride taken is calculated by the formula

In tab. 4 shows the results of the investigation of the reaction stoichiometry.

oxidation of ephedrine hydrochloride with potassium peridate (Osch5mo not 3.0-1 (G4; Sozzo4. 8.0-10; C Mn (s, n3 coo 2,0 -10 3; C c7HfNo4 5.0-10 mol / l PH 2.7-, T 295 K; 1 1 cm; A 504 nm; Specord spectrophotometer M 40)

The results presented in Table 4 show that potassium periodate reacts with ephedrine hydrochloride in a 1: 1 molar ratio and complete oxidation is reached 10 minutes after the start of the reaction at room temperature.

In tab. 5 shows the change in light absorption of the solution over time during the interaction of potassium periodate and manganese acetate (II) in the presence of dipicolinic acid (Soyo4 8.0-10; Mh (CH3cooit 2.0-10-e; CC 7H5N04 5, 0-1 O 3 mol / l; PH - 2.7; T 293 K; 1 1 cm; L 504 nm; Specord spectrophotometer M AO).

To determine the dependence of the light absorption of the blank solution on the duration of the potassium periodate reduction reaction using manganese (II) acetate in the presence of dipicolinic acid, the experiment was carried out in accordance with the above description of the method of quantitative determination of ephedrine hydrochloride with the only difference that at the time of adding the manganese acetate solution (ll) start the stopwatch and immediately rest

0

operations. The reduction of potassium periodate with an excess of manganese (II) acetate in the presence of dipicolinic acid under the conditions of the spraying process takes 3.5 minutes. In addition, after the end of the reaction, the light absorption of the solution does not change temporarily.

Thus, the proposed method for quantifying ephedrine hydrochloride using periodate oxidation, manganese acetate (II) and dipicolic acid reduces the time needed to restore the periodate excess by more than 6 times and shortens the time for the entire analysis by 25 minutes. In addition, the indicated {{nyuyu] method makes it possible to spectrophotometrize the solution in the visible region of the spectrum (at 504 nm) and eliminates the interfering influence of substances that absorb ultraviolet light at 281 nm.

0

five

F

The formula of the invention is a method for quantitative determination of ephedrine hydrochloride by treating the analyzed sample with a potassium period in a bicarbonate medium, reducing excess perisdate and spectrophotometrically characterized in that, in order to reduce the determination time, the reduction is carried out with manganese acetate (II) in the presence of dipicoline acid.

Table 1

PH

co “about: 10 mol / lA0

1541494 Table 2

Table 3

Table 4

0.0491 0.1915 0.4689 0.5281 0.5327 0.5330 0.5337

Editor V. Petrash

Compiled by S. Khovanska

Tehred L. Oliynyk Proof-reader V. Kabatsiy

Order 276

Circulation 510

VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5

Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101

1541494

Table 5

ten

0.5329 0.5321 0.5323 0.5337 0.5327 0.5322 0.5326

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Claims (1)

SUMMARY OF THE INVENTION A method for the quantitative determination of ephedrine hydrochloride by treatment of an analyzed sample with potassium periodate in a hydrocarbonate medium, recovery of excess periodate and spectrophotometry, characterized in that, in order to reduce the determination time, the reduction is carried out with manganese acetic acid (II) in the presence of dipicolinic acid. Table 1 CieHuNOnet) »g ——— Oh _oh Αχ Found g% Metrological characteristics 0.1547 0.5344 0.2804 0.1534 99.16 X = 99.94 0.1427 0.5388 0,3010 0.1424 99.79 S = 0.725 0.1640 0.5320 0.2611 0.1643 100.18 q ^and - X = 0.23 0.1450 0.5321 0.2961 0.1431 98.69 Oh = 10.52 0.1444 0.5300 0.2921 0.1448 100.30 0.1458 0.5310 0.2900 0.1465 100.48 0.1534 0.5292 0.2744 0.1554 101.30 0.1473 0.5345 0.2904 0.1474 100.07 0.1428 0.5315 0.2964 0.1427 99.93 0.1592 0.5310 0.2704 0.1584 99.50 table 2 pH pH Oh _oh 1.31 0.1644 2.88 0.4647 1,56 0.2949 3.15 0.4648 1, 86 0.3992 3.34 0.4686 2.01 0.4368 3.60 0.4650 2.15 0.4535 3.81 • 0.4628 2,30 0.4636 4.00 0.4625 2,53 0.4667 T a b faces 3 " „* 11), mol / l • ^And about. 1,0 0,0600 2.0 0.1228 4.0 0.2758 6.0 0.3968 8.0 0.5309 10.0 0.6693 12.0 0.7969 15.0 0.9878 Table 4 Time min Ao ⁿ K7O _f "μmol Stoichiometric coefficient n / 1 5 1 0.5313 0.3855 10.9768 0.7318 3 0.5294 0.3484 13,6759 0.9117 5 0.5282 0.3398 14,2673 0.9511 8 0.5304 0.3362 14.6455 0.9764 10 0.5327 0.3337 14.9427 0,9962 12 0.5323 0.3333 1'4,9540 0.9969 fifteen 0.5297 0.3311 14,9972 0,9998 20 0.5313 0.3337 14.8767 0.9918 25 0.5265. 0.3269 15,1643 1,0109 thirty 0.5304 0.3307 15,0603 1,0040 40 0.5286 0.3297 15.0511 1,0034 Table 5 Time min Oh _oh Time, min Oh _oh 1,5 0,0491 6.0 0.5329 2.0 0.1915 8.0 0.5321 2,5 0.4689 10.0 0.5323 3.0 0.5281 12.0 0.5337 3,5 0.5327 .14.0 0.5327 4.0 0.5330 16.0 0.5322 5,0 0.5337 20,0 0.5326