SU1150526A1 - Method of determination of alkyl sulphates in air - Google Patents

Abstract

A METHOD FOR DETERMINING ALKYLSULPHATES IN THE AIR by passing the analyzed sample through filters, extracting alkyl sulfates from a filter, adding a color reagent to the obtained extract, processing the mixture obtained, followed by photometry of the colored solution obtained, characterized in that As a color reagent, a 0.13% alcoholic solution of vanillin in the presence of sulfuric acid is used, and the mixture is heated by heating. on a boiling water bath followed by cooling and adding water.

Description

The invention relates to a technique for the analytical determination of toxic substances in air, 3 specifically to methods for determining alkyl sulfates of the composition (C H2) 0, 230, and C H 2, (where) with detergent properties and main component of various frothers. A known weight method for the determination of alkyl sulfate with pretreatment of the analyzed mixture with petroleum ether, distillation in a water bath with nitrogen supply, followed by dissolving in a mixture of chloroform, n-propanol and water, passing through a column with Sephadex, secondary distillation with nitrogen feeding, titration 0, 1 n. with a solution of potassium hydroxide in ethanol, evaporation to a dry residue in a water bath and weighing in Cl} The disadvantages of this method are laboriousness, duration, low sensitivity and accuracy. A known photometric method for the determination of alkyl sulfates is 2 j OSOjNa, where p 8, based on the known reaction of alkyl sulfates with rosaniline. The test solution prepared in phosphate buffer solution is mixed with rosaniline hydrochloride, shaken for 50 minutes with 5 ml of a mixture of equal volumes of chloroform and ethyl acetate, then centrifuged. The organic layer is separated and photometric at 540 named C2J. The disadvantages of this method are the duration and small sensitivity of HocTbj since it allows the determination of not less than 0.02 mol (4.64 mg) of the indicated alkyl sulfates in 4 ml of solution. The closest to the proposed technical essence and the achieved result is a photometric method for determining alkylsulphates in atmospheric air, based on their reaction with methylene blue as a color reagent, according to which the test air containing alkylsulfate aerosols is passed through AFA-B-1 filters with a speed 20 l / min for 20 min. A filter with a sample was treated twice with 3 MP of ethanol-water 6 mixture in a ratio of 1: 6. For analysis, 3 ml is taken from 6 ml of the test solution and placed in a separatory funnel. Then add 2 ml of alkaline phosphate buffer solution, 0.05 ml of 0.1% thymolphthalein solution and after the appearance of blue color, indicating the proper pH (10.0), color reagent is added, which is used as 1 ml. , 03% solution of methylene blue, and 3 ml of chloroform. The mixture is shaken for 1 min and after separation of the layers, the chloroform extract is extracted with an acidic methylene blue solution and a photometer, dips on an SF-10 recording spectrophotometer at a wavelength of 655 nm in a cuvette with a layer thickness of 1.5 cm. is 0.55, 0 µg in the analyzed SzI solution. However, the limestone method is characterized by laboriousness, insufficient sensitivity and accuracy of determination. The purpose of the invention is to simplify the definition, improve its sensitivity and accuracy. The goal is achieved according to the method of passing the test air through filters, extracting alkyl sulfates from the filter, adding a 0.1–3% alcohol solution of vanillin to the obtained extract in the presence of sulfuric acid, heating the mixture in a boiling water bath, cooling , adding water followed by photometric measurement of the obtained colored solution. Vanillin-4-hydroxy-5-methoxybenzaldehyde. 1 Example 1. A 200 l test air is passed through an AFA-VP-20 filter at a rate of 20 l / min. The filter is transferred to a funnel and washed twice with 2 ml of warm water into a test tube. For the analysis, 1 ml of the solution is taken, 3 ml of sulfuric acid are added, and after 5 minutes, 0.1 ml of a 2% alcoholic solution of vanillin is added. The sample is placed in a boiling water bath for 15 minutes, after cooling, 2 ml of distilled water is added, stirred, and after 20 minutes, the optical

the density of the solution at a wavelength of 536 and a layer thickness of 1.0 cm.

Cp build calibration graph prepare standard solution

alkyl sulfates in water with a content of 200 μg in 1 ml.

The scale of standards is presented in table 1.

Table 1

Sulfuric acid (f 1,84), ml

Vanillin solution, ml

The content of frother, mcg

The tubes are placed in a boiling water bath and then proceed as during sample processing.

Table 2 presents data on the effect of the concentration of vanillin solution.

table 2

20 20 20

LTD

In all test tubes on 3 ml In all test tubes on 0.1 ml

50

100

200

150

Continued table. 2

3

0.12 f 0.020 0.14 ± 0.030 0.13 ± 0.040

It can be seen from the above data that the optimal value of the concentration of vanillin is within 1-3% (the optical density of solutions in this range is almost the same).

Taking into account the need to create some excess reagent on the one hand and its economy, it is optimal to use in the reaction 2% concentration, a couple

vanilla.

Table 3 shows the results of the determination of alkyl sulfates in artificial solutions.

Table 4 shows the results.

analysis of air for the content of alkyl sulfate aerosol.

-Table 3

10.0 15.0 15.0

Continued table. j

Claims (1)

METHOD FOR DETERMINING ALKYL SULPHATES IN AIR by passing the analyzed sample through filters, extracting alkyl sulfates from the filter, adding a color reagent to the obtained extract, processing the resulting mixture with subsequent photometric measurements of the obtained colored solution, characterized in that, in order to simplify the determination and increase its sensitivity and accuracy, as a color reagent, a 0.13% alcohol solution of vanillin in the presence of sulfuric acid is used, and the resulting mixture is heated by boiling th water bath, followed by cooling and adding water.