SU911260A1 - Method of determination of acetylacetone in air - Google Patents

Description

The invention relates to environmental protection, in particular to methods for the quantitative determination of acetylacetone, and can be used to determine acetylacetone in a gas-air environment.

A known method for determining acetylacetone in air is based on treating the analyte with 2-t1-nitrobenzdehyde in an alkaline medium, followed by photometric measurement of the obtained colored compound 1.

The disadvantage of this method is its low sensitivity.

There is also known a method for determining acetonetone in air by passing an air sample through a solution of caustic soda, successively adding a 0.1% aqueous solution of furfural to the resulting solution, and concentrated sulfuric acid at room temperature, followed by photometric measurement of the resulting solution 2).

The disadvantage of this method is low sensitivity (above 50 µg).

. The circuit of the invention is to increase the sensitivity of the method.

This goal is achieved in the method of determining acetylacetone in air by passing an air sample through a solution of caustic soda, sequentially adding a furfural solution and concentrated sulfuric acid to the resulting mixture, followed by photometry of the resulting solution as a solution of furfural 0.29 0.31% solution of furfural and treatment with sulfuric acid is carried out at.

Example. After two successively connected Richter absorption devices containing 10 ml of distilled water, 7 liters of air are drawn in at a rate of 0.5 l / min. The contents of each absorption device are transferred to colorimetric tubes and analyzed separately. To do this, 0.5 ml of the test solution is placed in colorimetric test tubes with ground stoppers. Volume

The 25 solution is made up to 2 ml with 0.1 and sodium hydroxide solution. Then sequentially & Each tube is injected with 0.5 ml of a 20% solution of sodium hydroxide and O, 3 ± 0.01% 30 aqueous solution of furfural. Samples

mix thoroughly and hold at 20 ° C for 30 minutes. Then the samples are cooled before being placed in ice water, allowed to stand for 5 minutes and, not taken out, 2 ml of concentrated sulfuric acid are carefully added dropwise. After 5 min, the samples are removed from the coolant mixture and, after a 10-minute interval, the optical density of the solutions is measured at 520 in 10 mm cuvettes of the relative blank solution. The acetylacetone content in the sample is determined by

The results of determination of acetylacetone at a concentration of furfural solution of 0.29 and 0.31% and temperature O and

Vocational schedule, pic

triple by measuring optical

flesh, table. 1 and ti scale standards table. 2). In the presence of acetylacetone in the test solutions

the results are summarized. The amount of the soot containing the acetylacetone permeable trace in the air white is known

calculate the formula.

Sensitivity

the proposed method is 1 µg acetylacetone in 5 ml

3 or 3 solution.

T a b l i

c a

op'ata

Claims (2)

10.021 ± 0.002 0.023 ± 0.002 80.099 ± 0.003 0.102 ± 0.003 200.236 ± 0.007 0.243 ± 0.007 Claims for determining acetylacetone in air by passing a sample through a solution of sodium hydroxide, successively adding to the mixture a solution of fur0, 024 ± 0.001 0.02 ± 0.002 0.100 ± 0.002 0.10 ± 0.002 0.240 ± 0.003 0.23 ± 0.006 concentrated sulfuric FUROPE and ate food U1 (named after the photometric acid from the range, which was obtained by a person who received a feeling of sensation and furfural) As a solution, 0.29-0.31% solution of furfu59112606 is used. Rola and Processing concentrated1., Korenman U, M. Photometric sulfuric acid is carried out at analysis. M., Himi, 1970, p. 195, Sources of information, polymers. L., Himi, 1967, taken into account during the examination. 89 (prototype). 2. Peregud E.A. Sanitary chemistry