SU792114A1 - Method of quantitative determination of iodide-containing organic substances - Google Patents

Description

(54) METHOD OF QUANTITATIVE DETERMINATION

ORGANIC SUBSTANCES The invention relates to the field of analytical chemistry, namely, to methods for quantitative determination of iodide containing organic substances. A known method for the quantitative determination of iodide-containing organic substances by titration of an analyzed sample with a solution of silver nitrate N. The disadvantage of the method is low accuracy of determination. The closest to the described invention according to the technical essence and the achieved result is a method for quantitative determination of the iodide-containing organic substance by spectrophotometry of a desulfurized sample relative to a standard analyte solution, 2J. The disadvantage of this method is the difficulty of determining, since each definable substance needs its own standard. The aim of the invention is to simplify the method. The goal is achieved by the described method of quantitative determination of iodide-containing organic substances by spectrophotometry of the analyzed sample relative to potassium iodide. A distinctive feature of the process is the use of potassium iodide as an iodide reagent. It has been established that the spectrophotometric determination in the UV region of the spectrum of some iodide-containing substances is based on measuring the intensity of absorption of iodide ions, which are contained in the molecules of these substances. To illustrate the output, we present the spectra of some substances. In tab. Figure 1 shows the UV spectra of di-dimethylaminoethanol diiodomethylaminoethanol and succinic acid, (J), di-dimethylamino / b-dimethylamino-ethanol and 1,6-dimethylpipacolinic acid (1) diiodomethylaminoethyl dimethylaminoethanol and 1,6-dimethylpipecolinic acid, and they have added a diurethylaminoethanol and 1,6-dimethylpipacolinic acid. o-pyrrolidinecarboxylic acid (IV) .The spectrum of solutions of potassium iodide is also given, which contain as many iodide ions as there are in the molecules of the vets analyzed. coincided in nature and intensity. Thus, the spectrophotometric determination of substances is based on measuring the intensity of absorption of iodide ions containing molecules in substances

An example of quantification. About 0.1 g of the substance was accurately weighed to the mark with water (solution A), 1 ml of the resulting solution was placed in a 50 ml volumetric flask and the volume was adjusted to the mark with water (solution B). After stirring, the optical density of the resulting solution was measured with a spectrophotometer at a wavelength of 226 nm in a cuvette with a layer thickness of 1 cm against the background of water.

The calculation of the quantitative content of a substance should be made according to the formula

D b-250100%

   a-1000

where Su is the determined concentration of the substance,% j

D is the optical density of the analyte solution;

DO is the optical density of a standard potassium iodide solution;

a is the sample of the analyte;

b is the amount of analyte that corresponds to 1 ml of standard solution A of potassium iodide,

MG

For example, here is the calculation of the quantity of substance 7:

0.387.-0.4250 100% 0.382-0.1000.1000

1.013-100-100%. „. ., „101.30% 101.30%

Preparation of potassium iodide solution. A precise weighed amount of potassium iodide equal to 0.0611 g was dissolved in water in a 250 ml volumetric flask and the volume of the solution was adjusted to the mark with water. Next, the resulting solution arrived in the same way as when determining the analyzed substances.

The use of the proposed unified method for the quantitative determination of iodide-containing substances in the UV region of the spectrum will allow the analysis of iodide-containing substances

according to a single method and methodology.

The table shows the dependence of optical density on the wavelength l of solutions of the studied compounds and, potassium iodide.

7921146

Continued tabl,

Claims (2)

1. State pharmakon USSR. X edition, Medicine, M., 1968, with. 376. 2. VFS 42-467-75 Ditilin (prototype).