SU1490609A1 - Method of quantitative analysis of oleic acid - Google Patents

Abstract

This invention relates to analytical chemistry, in particular to the quantitative determination of oleic acid. The goal is to simplify and reduce the time of the process. The determination is carried out by treatment of the analyzed sample with cryptocyanin in the medium of borate buffer solution at PH 10 and photometric measurement of the obtained solution. The method provides a reduction in time by 7-8 times. 2 tab.

Description

This invention relates to analytical chemistry, in particular to the determination of oleic acid in wastewater from non-ferrous metallurgy plants.

The purpose of the invention is to simplify and reduce the time of the process.

Example. A 25 ml volumetric flask was introduced with 2-10 ml of waste water with an oleic acid content of 25-200 µg, diluted with distilled water to 10 ml, 10 ml of borate buffer solution with RC 10, 1 ml of 10 m cryptocyanin solution (1, 1-diethyl-4-quinocarbocyanin iodide) is adjusted to the mark with a buffer solution. Mix, after 5 min, the optical density of the spectrophotometer at 650 is measured in a cuvette of 1-10 mm relative to a buffer solution that does not contain a color reagent.

Comparative results of the oleic acid content determination according to the proposed method and according to the prototype (with methylene blue) are presented in Table 1.

In the study of the interaction of oleic acid with cryptocyanin, absorption spectra are taken at different pH values of the solutions. Analysis of the obtained spectra shows that in an alkaline medium, oleic acid interacts with cryptocyanin to form ionic associates. The greatest contrast in the intensity of the solution of cryptocyiaiin and the solution containing the ionic associate of Cryptocyanin with oleic acid is observed at pH 10. At pH

WITH

about with about with

11, a competing reaction is observed from the side of OH ions, which suppresses the interaction of the oleate ions with the organic reagent and makes it impossible to determine the oleic acid. At pH 9, the detection sensitivity decreases (see Table 2) o

In tab. Figure 2 presents the data on the determination of oleic acid with cryptocyanin at various pH values (the straightness of the calibration curve is observed at an oleic acid content of 25–200 µg).

The results in Table 2 show that it is preferable to perform the determination at. The blue color of the organic reagent after interaction with oleic acid changes to turquoise. Color develops in 3-5 minutes and is stable for 35-40 minutes. Cryptocyanin selectively reacts with oleic acid in the presence of other components.

0

five

0

wastewater of non-ferrous metallurgy enterprises: K, Na, Ca, Ni

24

With

and

2m

3 +

, F-, C1HCO

3

COj, OOP, SiOj. The intensity of the colonic solutions is inversely proportional to the content of oleic acid.

Thus, the use of the proposed method makes it possible to simplify and reduce the time spent on the determination of 7-8 times

Claims (1)

Invention Formula A method for quantitative determination of oleic acid by treating an analyzed sample with a color reagent and photometry of a solution, characterized in that, in order to simplify and shorten the time of the process, cryptocyanin is used as a color reagent and the treatment is carried out in a borate buffer solution at pH 10. t in n and a i Ajujm SH ru "my Sodertiniye olsmnoyuy acid, ig / l Prsdlaga Elosob Artificially prepared m water Worth WATER1 one I Proto P 0.025 7-8 h A8 0.062 7-Bh 27 0.030 7-8 h 45 0.040 7-8 h Table 2