SU1578604A1 - Method of determining phenol - Google Patents

Abstract

The invention relates to analytical chemistry, in particular the determination of phenol, which can be used in its production. The goal is to increase the sensitivity of the method. The latter are treated with a sample of a water-alcohol solution of iodine pentoxide, an alcoholic solution of paraphenyldiamine and an aqueous solution of alkali, followed by photometry of the resulting solution. In this case, the minimum detectable amount of phenol is 0.21 .10 -6 against 0.5 .10 -5 mol / l in the known case. 2 tab.

Description

This invention relates to analytical chemistry; Namely, the methods of quantitative determination of small concentrations of phenols in organic media can be used as a method for analyzing trace amounts of phenols in organic media in the refining, petrochemical and other industries.

The purpose of the invention is to increase the detection sensitivity.

The invention is illustrated by the following examples.

Example 1. A portion of the phenol is dissolved in a volumetric flask containing ethyl alcohol, and adjusted to the required concentration of phenol by dilution. An aliquot of 10 ml of solution is taken in a test tube and 1 ml of a water-alcohol solution (1: 9) of a pentoxide of iodine (J-jOj) of 0.2% concentration is added,

1 ml of a 0.1% solution of dimethyl para-phenylenediamine in ethyl alcohol and 0.4 ml of a 0.75% aqueous solution of alkali NaOH.

Due to the fact that iodine pentoxide has limited solubility in ethyl alcohol, the I-zPf PRPD suspension is dissolved in one part of distilled water and ethyl alcohol is added to a ratio of 1: 9.

After all the reagents are introduced into the test tube, the solution is kept for 30 minutes. After the indicated time has elapsed, the precipitated precipitate is filtered off, the solution is placed in a 20 mm cuvette to remove the optical density on a KFK-2 photoelectric colorimeter at a wavelength of 670 nm.

Based on the value of optical density on the calibration curve, determined i

00

about

the content of phenol in the analyzed solution is divided.

These definitions of phenols proposed and in a known manner are given in table 1.

Table 1

EXAMPLE 2 A portion of the phenol is dissolved in a volumetric flask containing isopropyl alcohol and, by dilution with isopropyl alcohol, brought to the desired concentration of phenol. The following analysis conditions are similar to those described in Example 1.

The results of the determination of phenol in the environment of isopropyl alcohol by the proposed method are presented in table 2.

Table 2

1,270-10

-five

The proposed method 1,272-S-5 + 1,5

From the results shown in Table 30, it can be seen that in the determination of phenols by the proposed method, the minimum detectable amount of phenol is 0.21-10 mol / l, and in a known manner 0.5-10 mol / l, i.e. 35, the sensitivity of the proposed method for the determination of phenols in organic media is 24 times higher than the known method. The proposed method allows to determine the concentration of phenols 40 in organic media with an error that is permissible when carrying out physicochemical analyzes.

From the data of Table 2 it can be seen that when determining the phenols in isopropyl alcohol by the proposed method, the sensitivity of the determination is higher than in the known method.

Claims (1)

Invention Formula The method of determining phenol by treating the sample being analyzed with chemical reagents followed by photometry of the resulting solution, characterized in that, in order to increase the sensitivity of the determination, a water-alcohol solution of pentoxide is used as chemical reagents. iodine, alcohol solution of dimethylparaphenylenediamine and aqueous alkali solution.