SU873119A1 - Sorbent for chromatographic separation and analysis of water media - Google Patents

Description

The invention relates to chromatography and can be used for the determination of organic impurities in water, and more specifically for the control of the composition of wastewater from the water disposal of formalin production, phenol formaldehyde epoxy resins. Water sorbents used in chromatography are known that can absorb, such as silica gel and molecular sieves. However, the first of these can absorb polar compounds and compounds with hydroxyl group, which are, in particular, formaldehyde, methanol and phenol. Molecular sieves can also absorb polar and polarizable substances. The activation of molecular sieves (removal of hydration water) is carried out for several hours at 350-450 ° C. 1.. However, the listed features make it difficult to use these sorbents in the quantitative chromatographic analysis of water patches with organic substances, as well as in the water runoffs of petrochemical synthesis production, which carry pollutants in their waters. Known clinoptilolite Ay-Dagskogo deposits of the Azerbaijan SSR. This clinoptilotite, the idealized composition of which ((Ma2K2Ca) s AeSiwO 24HiO), has, in contrast to other natural zeolites, high heat resistance, resistance to aggressive media, and sufficient mechanical strength. clinoptilolite of high mechanical strength eliminates the need for their granulation 2. Various areas have been described in which clinolptnolitic zeolites are used: the use of for the purification of water from ammonia and methanol. Zeolites are known, the use of which njMi for drying gas systems has several advantages over other adsorbents, such as silica gel or molecular sieves. First Yuganoptilolite is able to absorb water in much larger quantities; secondly, as the temperature rises, its adsorption capacity relative to water decreases not as dramatically as that of silica gel or molecular sieves; thirdly, they create a low hydraulic resistance of the adsorbent when the gas flow moves through the zeolite layer; fourth, zeolites have a pronounced selectivity for certain compounds 3.

However, there is no information in the literature on the use of clinoptilolite in the chromatographic analysis of aqueous media. The use of clinoptilolite as an absorber of water before chromatographic separation is proposed.

and analysis of aqueous media containing impurities of organic substances. "

For this purpose, clinoptilolite of the Ay-Dag field is used, which works sidewise in the temperature range of 60-70 ° C and is easily regenerated in the process of analysis by the method of reverse blowing. At 60-70 ° C, clinoptilolite selectively absorbs only water vapors, and all other impurities pass without delay; into the chromatographic column.

Example. The clinoptilolite of the Ay-Dag deposit of the Azerbaijan SSR is crushed in a mortar, the fraction removed is 0.3-0.5 mm, calcined at 300-400 ° C for 3 hours, cooled in a desiccator and filled with a forcolon with a length of 20 cm and an internal diameter of 3 mm. The column is placed in the thermostat of the LHM-72 chromatograph between the sample introduction unit and the analytical separation column. The analytical column with a length of 2 m and an internal diameter of 3 mm is filled with a dinochrome-1 fraction of 0.30, 35 mm impregnated with 10% (weight) polydistillene glycol sulfate succinate. Set the initial conditions of the analysis: the temperature of the column thermostat 60 ° C; the temperature of the detector thermostat is 190 ° C, the temperature of the sample introduction unit is 250 ° C; detector current 140 hpA; gas carrier velocity gels 50. A sample of waste water from phenol-formaldehyde resin production of 0.2 ml is fed to the injection unit of the hrymatograf. After one minute, impurities of formaldehyde, methanol, and phenol pass through the column and enter the main analytical column. At this moment, the programming unit is turned on and the temperature rises to 190 ° C at a rate of 10 ° C / min. Simultaneously with the activation of temperature programming, the forcolk is back blown to regenerate clinoptilolite from sorbed water vapor. Having reached a temperature of 190 ° C, the analysis is continued under isothermal conditions for 10 minutes. The impurities analyzed were eluted from the chromatographic separation column with the following exit times; methanol - 2.1 min; formaldehyde 7.35 min; phenol - 21.9 min.

After completion of the analysis, using an absolute calibration method, calculate the quantitative content of impurities, which is in this particular case: methanol

formaldehyde phenol 3 ,.

Example 2. A sample of water containing 0.003 g / l toluene and 0.005 g / l zpichlorohydrin, which are the main polluters of epoxy resin production, is fed to the assembly

sample input under the conditions described in the first example. After one minute, toluene and epichlorohydrin undergo forcolonols with clinoptilolite, and water is retained in it, sorbing with clinoptilolite. After the peak of toluene is released (its retention time is 1.8 minutes), the temperature programming block is turned on and the temperature rises to 190 ° C at a rate of 10 ° C / min. At the same time, the forcolon switches to reverse purge. Time

epichlorohydrin retention 3.6 min. Quantitative determination of these contaminants is also carried out by the method of absolute calibration of the instrument.

The quantitative interpretation of the peaks obtained by chromatographing this mixture confirms the free passage of toluene and epichlorohydrin through the forcolon filled with clinoptilolite in a selected temperature mode. The use of natural clinoptilolite in the chromatographic determination of organic impurities in water contributes to the selective absorption of water and

elimination of interference last in the analysis of aquatic environments. This, in turn, leads to an increase in the sensitivity of the method for determining impurities to (weight) without prior concentration.

Since the need for phenol-formaldehyde and epoxy resins in formalin is constantly growing and the number of industries producing these products increases, the proposed invention, aimed at controlling the drains of these objects, serves to protect the environment from pollution.

Claims (3)

Invention Formula Use over-clinoptilolite as a sorbent for gas chromatographic separation and analysis of aqueous media containing impurities of organic substances. Sources of information taken into consideration during the examination 1. Lurie A. A. Sorbents and chromatographic media. M., Himi, 1977, p. 207. 273. 58731196 2. Clinoptiloliths. Proceedings of the symposium on water 3. Tsitsishvili R.V., Avdronikashvili T.G. Prospects for the study and application of clinoptiloli Natural zeolites and their potential to be used, Tbilisi, 2-4 November 1974, Tbilisi, Medical facilities in the national economy. Overview of Tbilisi, Nisraba, 1977,1978 (prototype).