SU1617336A1 - Method of determining 6-(phenoxyacetamido)-penicillanic acid and disodium salt of 6-(alfa-carboxyphenylacetamido) - of penicillanic acid - Google Patents

Abstract

This invention relates to analytical chemistry, in particular to the determination of 6- (phenoxyacetamido) -penicillanic acid and the disodium salt of 6- (α-carboxyphenylacetamido) -penicillanic acid. The goal is to increase the accuracy, selectivity of the determination and reduce the time spent on the method. Getting lead by processing the analyzed sample with a solution of potassium nitrate in conc. H ₂ SO ₄ , diluting the reaction mixture with water. The process is carried out with the subsequent processing of the mixture obtained with a solution of 2,3,5-triphenyltetrazol at PH 9, the colored product is extracted with trichloromethane and photometric. The method reduces the analysis time 1.5-2 times and improves the accuracy of the determination (the relative error decreases from 4% to 1.86%). 3 tab.

Description

The invention relates to analytical chemistry, in particular to the analysis of 6- (phenaxiacetamido) -penicillanic acid and disodium salt of 6- (c6-carboxyphenylacetamido) -penicillanic acid and can be applied in factory control and analytical laboratories, central chemical laboratories an enterprise.

The purpose of the invention is to improve the accuracy, selectivity of the determination and reduce the time spent on the method.

Example 1. Determination of 6- (phenoxy-acetamido) -penicillanic acid.

1. Qualitative definition.

About 2 mg of 6- (phenoxyacetamido) - -penicillanic acid are placed in a evaporator cup, 0.5 ml of 10% solution of potassium nitrate in concentrated sulfuric acid is added and the contents of the cup are stirred until complete dissolution of the 6- (phenoxyacetamido) -penicillin is reacted new acid. With the resulting solution was added with stirring

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1 ml of oxen and portions of a 10% solution of sodium hydroxide, transfer the contents of the tea into a glass cup and at the same time thus neutralize the acid reaction of the solution to neutral or weakly alkaline pH values. Then 5 ml of universal buffer, bringing the medium to pH 9, and 4 ml of a 0.15% solution of 2,3,5-triphenyltetrazol chloride are added. The resulting product is extracted with 10 ml of trichloromethane. The tr of chloromethane layer is colored yellow. The sensitivity of the reaction is 2.5 µg / ml.

2. Quantitative determination. By the method of isomolar series and saturation, it was established that 6- (phenoxy-acetamido) -penicillanic acid and 2,3,5-triphenyltetrazol chloride react in a molar ratio of 1: 1. The absorption maxima of the reaction product (solution in trichloromethane) are at 374 and 415 nm.

I Construction of the calibration schedule I B six evaporation cups hold 0.25; 0.50; 1,00; 1.50; 2.00 and | 2.50 ml of 0.05% acetone plant- JBopa 6- (phenoxyacetamido) -penicillinate | n-bvoic acid and the solvent is evaporated until a dry residue is obtained. Each cup is filled with 0.5 ml of 10% jpacTBopa potassium nitrate in a centered centric sulfuric acid and the contents of the cups are stirred until complete dissolution of the reacted 6- (phenoxyacetamido) -penicillanic acid. While stirring, 1 ml of water and portions were added to the resulting solutions, and a 10% solution of sodium hydroxide; P, transfer the contents of the cups to: glass cups. And at the same time neutralize the acidic reaction of the solution to neutral or slightly alkaline pH values. Then 5 ml of universal buffer K dovodt reaction of the medium to pH 9) and a ml of a 0.15% solution of 2,3,5-trienyl tetrazolium chloride are added. The product formed is extracted with two ml trichloro-methane of 10 ml. The extracts are combined in a 5 ml volumetric flask and adjusted to Netka with trichloromethane. The optical density of the colored solutions is measured on a KFK-2 photoelectric colorimeter at a wavelength of 400 nm (optical filter No. 3) in a cell with a working layer thickness

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25

 °

50

five

50 mm. The comparison solution is the extract obtained in the control experiment. Based on the measurement results, a calibration graph is constructed. The light absorption of the colored solutions is in accordance with the Bouguer-Lambert-Beer law in the concentration range of 5-50 μg / ml. The least squares method calculates the equation of the calibration graph, which in this case has the form: D 0,01596 С + + 0,01901, where D is the optical density; C is the concentration of the analyte in the photometric solution, µg / ml.

Quantitative determination method.

About 0.05 g (exact weight)

6- (phenoxyacetamido) -penicillanic acid is dissolved in a 50 ml volumetric flask in acetone. 0.75 ml of the solution obtained is introduced into the evaporating dish and further operations are carried out according to the scheme described for the construction of the calibration graph. Determination of the quantitative content of 6- (phenoxyacetamido) -pencylpanic acid is carried out according to the equation of the calibration graph and recalculated for the sample. The results of the determination and metrological characteristics are presented in Table. one.

Example 2. Determination of disodium salt of 6- (o4-carboxyphenylacetic-amido) -penicillanic acid. 1. Qualitative definition. About 2 mg of the disodium salt of 6- (j) 6-carboxyphenylacetamido) -penicillic acid is placed in an evaporation cup, 0.5 ml of a 10% aqueous solution of potassium nitrate in concentrated sulfuric acid is added and the contents of the cup are stirred until complete dissolution of the reacted disodium salt

6- (o1: -carboxyphenylacetamido) -penicillanoic acid. Under stirring, 1 ml of water and 10% sodium hydroxide solution are added in portions to the resulting solution, transferring the contents of the cup to a glass beaker and at the same time neutralizing the acid reaction of the solution to neutral or slightly alkaline pH values. Then, 5 ml of the universal buffer was added, bringing the medium to pH 9, and 4 ml of a 0.15% solution of 2,3,5-triphenyltetrazol chloride. The resulting extract product is that state of emergency

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trichloromethane. The trihpormethane layer is colored yellow. The sensitivity of the reaction is 0.8 μg / ml.

2. Quantitative determination. By the method of isomolar series and saturation, it was established that the disodium salt of 6 - (() - carboxyphenylacetamido) - - penicillanic acid and 2,3,5-three phenyl tetrazolium chloride react in a molar ratio of 2: 1. The maximum absorption of the reaction product (solution in trichloromethane) is at 375 im.

Construction of the calibration schedule B five evaporation cups contribute 0.25; 0.50; 1,00; 1.50 and 2.00 ml of a standard (0.025%) ethanol solution of disodium salt of 6- (o6 -carboxy-phenes-acetamido) -penicillinic acid and the solvent is evaporated to obtain dry residues. 0.5 ml of a 10% solution of potassium nitrate in concentrated sulfuric acid is added to each cup and the contents of the cups are stirred until all the reacted disodium salt of b- (o-carboxyphenylacetamido) -penicillanic acid is dissolved. With the stirring, 1 ml of water and 10% sodium hydroxide solution are added in portions, transferring the contents of the cups to glass cups and at the same time neutralizing the acid reaction of the solution to neutral or weakly alkaline pH. Then 5 ml of universal buffer was added, bringing the medium to pH 9, and 4 ml of a 0.15% solution of 2,3,5-triphenyltetrazol chloride. The resulting product is extracted with trichloromethane twice in 10 ml. The extracts were combined in a 25 ml volumetric flask and made up to the mark with trichloromethane. The optical density of the colored solutions was measured on a KFK-2 photoelectric colorimeter at a wavelength of 400 nm (light filter No. 3) in a cuvette with a working layer of 50 mm. The test solution was an extract obtained in the test experiment. . The light absorption of the colored solutions is governed by the Bouguer-Lambert-Beer law in the concentration range 2.5–20, O μg / ml. By the least squares method, the calibration curve equation is calculated, which in this case has

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15

25

20

thirty

35

40

45

0

Type D 0.01873-C + 0.09732, where D is the optical density, C is the concentration of the analyte in the photometric solution, µg / ml.

Quantitative determination method.

About 0.025 g (exact weight) of 6- (L-carboxyphenyl-acetamido) -penicillanic acid disodium salt is dissolved in ethanol in a 50 ml volumetric flask. 0.5 ml of the resulting solution is added to evaporation tea. The ethanol is evaporated and further operations are carried out according to the scheme described for the construction of a calibration graph. The determination of the quantitative content of the 6- (oi.-K ar bacoxyphenyl acetic amide o) -α-penicillanic acid disodium salt is carried out according to the equation of the calibration graph and recalculated for the weight. The results of the determination and metrological characteristics are presented in Table 2.

The proposed method compared with the known increases the selectivity of the determination. Unlike the known method, it allows the analysis of 6- (phenoxyacetamido) -penicillanic acid and the disodium salt of 6- (K-carboxyphenylacetamido) -penicillanic acid in the presence of benzene, alkyl benzenes , halobenzenes, benzoic acid derivatives, not containing riboflavin nitro groups. The definition does not interfere with a series of one or more nitro groups in its structure (B-C-treo-1-p-nitrophenyl-2 dichloro-acetyl amine, propane ol--1,3; 2,4-dinitrochlorobenzene; 3, 5-dinitro-6-chlorobenzoic acid), as well as various inorganic compounds with their own color.

I

The proposed method reduces the analysis time by 1.5-2 times and increases the accuracy of the determination (the relative error decreases from 4 to 1.86%). Comparative characteristics of the proposed and known methods are presented in table 3.

Claims (1)

Invention Formula . 20 - 55 Method for determination of 6- (phenoxy-acet-amido) -penicillanic acid and disodium salt of 6- (p {, -carboxyphenyl-acetamido) -penicillanic acid 1617336 by processing the analyzed sample of picTBopoM potassium nitrate in concentrated sulfuric acid, diluted with L (5) of the reaction mixture with water, color reagent in alkaline medium, followed by photometry of the resulting solution, with the aim of eight For accuracy, selectivity, and time reduction, the solution is 2,3,5-β-trifensttetrazolyl as a color reagent, processed with a color reagent at pH 9, the colored product is extracted with trichloromethane before photometry. Table 1 Results of quantification of 6- (phenone-oxiacetamido) -penicillanic acid. Table 2 The results of the quantitative determination of the disodium salt of 6 - ("(- carboxyphenylacetamido) -penicillic acid Table 3 Comparative characteristics of the proposed and known methods Compare parameters The proposed method selectivity The method allows the selective determination of 6- (phenoxy-acetamido) -penicillanic acid and 6- (oC-carboxyphenylacetamide-disodium) disodium salt of penicillanic acid in the presence of benzene, alkyl benzenes, halobenzenes, benzoic acid derivatives not containing nitro groups, riboflavin. The definition does not interfere with the range of nitro compounds: D - (-) -.-Threo-1-p-nitrophenyl-2- -dichloroacetylaminopropane 1 and ol-1, 3; 2,4-din it - rochlorbenzo l; 3,5-dinitro-6-chlorobenzoic acid, as well as various inorganic substances with their own color 15-18 min 1.85 Known method The method does not allow the selective determination of b- (phenoxyacetamido) - -penicillanic acid and 6- (c) disodium salt of C-carboxy-fensh1-acetamido) -penicillanic acid in the presence of benzene, alkyl benzenes, hapogenbenzenes, and some derivatives. benzoic acid, not containing nitro groups, riboflavin. A number of nitro compounds interfere with the determination: B - (-) - threo -1-p-nitrophenyl-2-di-lo-acetylamine-propan-diol-1,3; 2,4-dinitrochlorobenzene; 3,5-dinitro-6-chlorobenzoic acid, as well as various inorganic substances with their own color 30-35 min f4