CS273528B1 - Method of sulphur compounds' trace amounts analysis - Google Patents

Abstract

The solution concerns the method of determination of the concentration of traces of sulphur compounds in industrial exhalations and environment by concentration of sulphur substances, desorption, and subsequent analysis by the method of gas chromatography and use of flame photometric detector.

Description

Thus, from very low concentrations, the determination of these substances in industrial emissions and the environment is an important prerequisite for air quality control.

Leaders in the analysis of trace amounts of complex compounds have recently acquired gas chromatograph-based analyzers with a flame-photometric detector. Detection of irradiated substances by this device is one of the most elective and most sensitive methods of detection technique (flame-photometric detector, without the help of special columns of β preparations, it is possible to prove the presence of vpm units of these substances).

However, it is necessary that the individual substances present in the sample enter the detector separately! since many of them negatively / negatively affect the sensitivity of the detection of sulfur compounds. Hydrocarbons The sensitivity of the determination of the content of humid compounds can be substantially increased by using a packed concentration column to concentrate the analyzed substances and then desorb them into the gas chromatograph injection chamber. Sensitivity will also be increased by limiting the irreversible sorption of the sulfur compounds on the gas chromatograph equipment, the separation column materials and the sample boxes. Because of the high usual concentrations of sulfur dioxide relative to the content of other slurries,

SUMMARY OF THE INVENTION The present invention is directed to a method for analyzing trace amounts of the humorous compounds by terminating them, releasing them and then separating them on a gas chromatograph column to be prepared.

At temperatures of 5 to -100 ° C, the sulfur compounds are concentrated on a porous 2,6-diphenylene oxide polymer, thermally desorbed at a temperature of 100 to 400 ° C, and analyzed by the gas chromatography method using Teflon separation chromatography columns packed with a stationary phase 0, 5% tricresyl phosphate, 1% phosphoric acid and 5.4% 1,2,3-trie (2-cyanathoxy) propane on a Teflon carrier.

Example

Working conditions;

Apparatus Chromatographic apparatus and flame-photomatic detector (PFD)

PFD temperature: 105 ° C

PFD hydrogen flow rate: 110 ml / mln

Air flow: PFD: 84 ml / min

Maximum throughput of PFD interference filter; 394 nm ·

Teflon chromatography column:

Teflon column 2 000 x 2 mm

Fill: 0.5% Tricresyl phosphate, 1% phosphoric acid ,; 5.4% l, -2.3 »- tris (2-cyanoethoxy) propane on a Teflon-type support

Column working temperature: 35 ° C Heat conducting temperature: 110 ° c Carrier gas flow: 15 ml / min Packing temperature at column filling: -10 ° C

Concentration box:

Filling: 1.2 ml porous 2 ', 6-diphenyl-p-phenylenedioxide polymer

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CS 273528 Bl

Sampling rate: 1.5 L / min

Desorption temperature: 200 ° C

Sampling temperature: -50 ° C

The preparation of chromatographic cartridges with a Teflon carrier is carried out by wetting the carrier with a stationary phase dissolved in a suitable solvent and subsequent evaporation of the solvent. packings associated with disproportionate increase in pressure resistance of the chromatographic column · Uniform loading of the chromatographic column with vibrator, or tapping of the column with a suitable object *

For the concentration of sulfur substances, a concentration column is used. 2 which comprises a porous, ^l 6-diphenyl-p-fenylenoxldový polymer *! which is stable up to 400 ° C, has good absorption characteristics and does not significantly retain water vapor * Conditioned for 1 hour at 250 ° C prior to analysis 5 to - 100 ° C /, Low temperature must be maintained until the concentration column is placed in the chromatographic injection chamber *

After thermal desorption in the injection chamber of the chromatographic apparatus, the gas chamber switch is placed in the injection chamber space into the carrier gas stream * which flows through the chromatographic column and enters the flame-photometric detector of the apparatus *.

The chromatographic column is Teflon loaded with a stationary phase of 0 * 5% tricresyl phosphate, 1% phosphoric acid and 5 * 4% 1,2,3-tris- (2-cyanethoxy) propane on a Teflon carrier *

Standard samples can be prepared from concentrated sulfur by subsequent dilution in sample tubes washed with water * 3% aqueous hydrochloric acid solution and distilled water * After thorough drying and flushing with chromatographic nitrogen, the sample tubes are ready for use.

The diffusion standard is prepared by diffusion of the sulfur compound through a suitable membrane (under given temperature and pressure conditions) into the measured amount of gas passing through *

Dilution of the concentrated substance in special plastic sample boxes can also be used. Standards are stable for 2 hours * If the gas sample to be analyzed is humid, it must be cooled to less than 3 ° C in a laboratory refrigerator before being introduced into the concentration column *

Chromatograms are evaluated by the absolute calibration method. 'The concentration of the output signal is an exponential function *

Claims (1)

P ff E D M e T Method for analyzing trace amounts of sulfur compounds, characterized in that at a temperature of 5 to -100 ° C the sulfur compounds are concentrated to a porous 2,6-diphenylene oxide polymer. thermally de-adsorb at 100-400 ° C and analyzed by gas chromatography using Teflon Separation Chromatography columns and stationary phase 0 * 5% tricresyl phosphate * 1% phosphoric acid and 5.14% 1,2,3-tris (2-cyanethoxy) propane on a Teflon carrier. .... .