Method for detecting antimony in sewage water

FIELD: analytical chemistry and ecology, in particular, method for determining micro-concentrations of antimony in water.

SUBSTANCE: method includes preparation of analyzed sample by concentrating analyzed solution, which contains antimony, to the state of solid residual, dissolution of dry residual in 3,5-4,0 M hydrochloric acid, placement of prepared sample in a solution which contains 30-40% of potassium iodide, 10-15% solution of ascorbic acid, aging of resulting mixture over 15-25 minutes and addition of metallic zinc, distillation of resulting product by letting it through absorbing solution of partially oxidized diphenyl carbazide until the color of absorbing solution stops changing, photometry of absorbing solution.

EFFECT: increased selectivity and sensitivity of analysis.

3 ex, 3 tbl, 1 dwg

 

The invention relates to chemical methods of analysis of trace and can be applied in analytical chemistry and ecology, in particular for the determination of trace antimony in water.

Antimony is among the relatively widespread pollutants in natural waters, because of the wide use of its compounds in agriculture and industry. MAC antimony in water for sanitary-hygienic standards is 50 micrograms/l NEMOTEK A.A. Analytical chemistry of antimony. M.: Nauka, 1978, p.44-51, which imposes the relevant requirements on the methods of its determination in water.

The known method of determination of antimony, including the transfer of the analyzed material in the solution, the introduction of the solution of the basic dye - genesaret green, extraction of the formed ion associate with an organic solvent in the presence of 2-5 n solution of sulfuric acid and subsequent measurement of the optical density of the extract. The definition does not interfere with 3000-fold excess of Nickel, 6000-fold cobalt, 1000 times of copper, 1600-fold manganese, 40-fold, gold, 600-fold bismuth, 1000-fold zinc, 50-fold waist. SU 1458816, G01N 31/22, 1989.15.02.

Known methods for determining the concentrations of antimony, based on the ability of antimony to form colored complexes with inorganic anions. SU 1270696, G01N 31/2, 1/28, 1989.15.02.

However, the known methods are quite time-consuming, are not sufficiently low detection limits.

For the determination of antimony in various objects it is usually separated from the interfering components by distillation in the form of STIBINE with photometric end by reaction with diethyldithiocarbamate silver. Interfere with the determination of arsenic and germanium, Nemotek AA "Analytical chemistry of antimony, M.: Nauka, 1978, 232 S.

It is known that antimony and its compounds interact with organic reagents, which include-S-2SH-,=,- N=N - group. One of these reagents for the qualitative determination of antimony, is an alcoholic solution of partially oxidized diphenylcarbazide (DPC), which reacts complexation with antimony (III). Jelvis A.I. "Quality colored reaction to antimony", Journal of analytical chemistry, 1957, Vol.12, No. 3, s.

However, this reaction is used for the qualitative determination of antimony.

The task of the claimed invention is to provide a quantitative method for the determination of antimony in the wastewater by photometry.

The technical result of the claimed invention is to improve the selectivity and sensitivity of detection.

This is achieved by the method of determination of antimony in the wastewater, characterized by the fact that he cover the t preparation of the sample by concentrating the solution, containing antimony to the dry residue, dissolving the dry residue in the 3.5-4 M hydrochloric acid, placing the prepared sample in a solution containing 30-40% solution of potassium iodide, 10-15% solution of ascorbic acid, the extract mixture within 15-25 minutes and adding metallic zinc, the distillation of the product passing through the absorbing solution of partially oxidized diphenylcarbazide to stop discoloration absorbing solution, photomatrixovina absorbing solution.

The distinction of the proposed solutions is known in quantitative method for determination of antimony in the form of STIBINE (hydride), based on the distillate in a solution of partially oxidized diphenylcarbazide (the solution contains a mixture of diphenylcarbazide and diphenylcarbazone; the latter is necessary for the occurrence of redox reactions between stibines and diphenylcarbazone accompanied by the formation of diphenylcarbazide and antimony (III)with subsequent photometry formed of the reaction product. The distillation of antimony in the form of STIBINE increases the selectivity of the determination, as this separates the backing from the element (antimony). Use as defined shape Steben, instead of antimony (III) can improve the detection sensitivity, which contributes to the ability to skin the deposits diphenylcarbazide as the final reaction reagent.

To increase the sensitivity of the method may use utilizability environment. Jelvis A.I. "Quality colored reaction to antimony", Journal of analytical chemistry, 1957, Vol.12, No. 3, s.

The invention consists in the preparation of the sample by the concentration of the analyzed solution to the dry residue and dissolving the dry residue in hydrochloric acid, STIBINE (hydride) by placing the prepared sample in a solution containing a solution of potassium iodide and ascorbic acid, the extract mixture within 15-25 minutes and adding metallic zinc, the Stripping spin-off STIBINE, passing through the adsorption alcoholic solution of partially oxidized solution diphenylcarbazide to stop discoloration absorbing solution, photomatrixovina absorbing solution.

Example 1.

Source 0.5 g/l of antimony solution was prepared by dissolving 0,468 g SbCl3in 500 ml of water with addition of 50 ml HCl (ρ=1,19 g/ml). Its concentration was checked permanentresidence.

Working solutions of antimony at a concentration of 4 µg/ml were prepared by dilution immediately before use.

In the analyzed water sample volume of 500 ml was dissolved 10 g of magnesium oxide and 10 g of magnesium nitrate to alkalization of the solution. Then, the sample was boiled away the dryness. The dry residue was dissolved in 10 m is 4 M HCl and quantitatively transferred into the reaction flask setup to flush a volume of 25 ml, containing 1.5 ml of 40%aqueous solution of potassium iodide, 1 ml of 10%ascorbic acid solution. After 25 minutes, the reaction flask was placed 4 g of zinc and joined it with the venting tube containing the filter, which is wool impregnated with lead acetate and potassium hydroxide to the absorption cell containing 10 ml of 1% alcohol partially oxidized solution diphenylcarbazide. Adsorption vessel protected from light.

In the process of distillation of STIBINE, reactive diphenylcarbazide, change color saturation of the solution. The distillation was carried out for 30-40 minutes until the termination of discoloration absorbing solution. The optical density of the solution was measured at 590 nm relative to the source reagent solution aged at all times during the distillation in the dark. According to the results of the analysis of conditional molar absorption coefficient at a wavelength of 590 nm was εs=4,0·103. To account for the presence of antimony impurities in the reagents required production control experience

Example 2. The method was carried out analogously to example 1, but after evaporation the residue was dissolved in 10 ml of 3.5 M HCl and placed in a solution consisting of 30%aqueous solution of potassium iodide, 1 ml of 15%aqueous solution of ascorbic acid in the absorption cell was placed 10 ml of 1%partially ocil the spent solution of ethyl diphenylcarbazide and 5 ml of isoamyl alcohol.

To study the selectivity of the claimed invention in a solution containing all reagents according to the method, add the standard solution of arsenic (see example 3).

Example 3. The method was carried out analogously to example 1, but the original 0.5 g/l of antimony solution was prepared by dissolving in a volumetric flask 500 ml 0,468 g SbCl3in 50 ml of HCl (ρ=1,19 g/ml). Volume in a volumetric flask was diluted to the mark. The concentration of the solution was checked permanentresidence.

The original 0.9 g/l solution of arsenic were prepared by dissolving 0,119 g As2O31 N. the sodium hydroxide solution in a volumetric flask of 100 ml

Working solutions of antimony and arsenic concentration of 4 µg/ml were prepared by dilution immediately before use.

The determination of antimony by the claimed method does not interfere with arsenic in stevemeadedesigns.com exceeding its relative quantities of antimony. To determine the effect of arsenic on the determination of antimony in the reaction flask containing all of the reagents were added standard solution of arsenic and drove the solution obtained by the above method. The concentration of antimony was determined by calibration curve (see drawing), built using a standard solution of antimony. The influence of arsenic on the determination of antimony are shown in table 1. The calibration curve was constructed by standard solutions of antimony, definition wide-angle results is shown in table 2, on which was built the calibration graph (see drawing). The results of determination of antimony in the waste water are given in table 3.

The data show that the detection limit for 3S criterion was 10 μg. The method allows to determine from 18 ág/l to 130 mg/l in the sample with an accuracy of 28% to 7.6%.

Thus, the proposed method of determination of antimony in the wastewater allows you to define from 10 µg of antimony in the sample, which improves the selectivity and sensitivity of detection.

For analysis we used the following reagents: ascorbic acid GOST-4815-76; diphenylcarbazide TU-6-09-07-1672-89; and soliloquy alcohol GOST-5830-79; ethyl alcohol GOST-1830-87; potassium iodide GOST-4232-74; potassium hydroxide GOST-24363-80; sodium hydroxide GOST-4328-77; hydrochloric acid GOST-14261-77; granular zinc TU-6-09-5294-86.

Trichloride antimony TU-6-09-636-76; arsenous Anhydride GOST-1973-77.

Table 1
The influence of arsenic on the distillation of antimony (λ=590 nm, l=2 cm, n=3).
The number warded off antimony mgThe number warded off arsenic, mgΔAnd
0,0100,070
0,010,900,071
0,011,800,70
0,0200,131
0,021,800,131
0,023,600,131
0,0300,197
0,032,700,197
0,03of 5.400,198
0,0400,262
0,043,60to 0.263
0,047,200,262
0,0500,328
0,054,500,327
0,059,000,327
0,0600,392
0,06of 5.400,392
0,0610,80,393

Table 2
The change in optical density of the absorption solution from the number warded off antimony(λ=590 nm, l=2 cm, n=3).
The number warded off antimony mgΔAnd
0,010,07
0,020,131
0,030,197
0,040,262
0,328
0,060,392

Table 3
The antimony content in the waste water (λ=590 nm, l=2 cm, n=5)
No. sampleIntroduced antimony mg/lΔAndFound antimony, mg/lSr, %
I*0,00

0.02

0.04

0,06
0,20

0,27

0,33

0,43
0,061±0,012

0,082±0,011

0,101±0,012

0,131±0,011
19,7

13,4

11,9

8,4
II**0,00

0.02

0.04

0,06
0,050

0,1260

0,220

0,270
0,031±0,006

0,052±0,006

0,070±0,006

0,092±0,007
19,4

11,5

8,6

7,6
III***0,00

0.02

0.04

0,06
0,03

0,09

0,14

0,19
0,018±0,005

0,040±0,006

0,058±0,006

0,079±0,006
27,8

15,0

10,3

7,6
*) wastewater engineering company I;
**) waste water engineering enterprise II;
***) the river water below the discharge;
Sr - accuracy determination is possible

Thus, the proposed method for the photometric determination of antimony allows you to reliably and accurately determine the antimony when its content in the analyzed objects from 0.02 mg/l no branches related items.

The method of determination of antimony in the wastewater, characterized in that it provides for the preparation of the sample by the concentration of the analyzed solution containing antimony, until the solids dissolve the dry residue in the 3.5-4.0 M hydrochloric acid, placing the prepared sample in a solution containing 30-40%solution of potassium iodide, 10-15%solution of ascorbic acid, the extract mixture for 15-25 min, and adding metallic zinc, the distillation of the product passing through the absorbing solution of partially oxidized diphenylcarbazide to stop discoloration absorbing solution, photomatrixovina absorbing solution.



 

Same patents:

FIELD: environmental monitoring.

SUBSTANCE: invention relates to the area of utilizing microbiological objects for checking environmental pollution and can find use in environmental monitoring and sanitary-toxicological inspection of water, soils as well as in pharmacology when estimating safety of biologically active substances. Method consists in registration of variability of nature of colony-formation of two yeast strains Sacharomyces cerevisae exhibiting different ploideness under different medium conditions. Haploid and diploid strains are used. Toxic effect is established from lethal characteristics and mutagenicity from rise in number of mutant forms of colonies. Thereafter, induction of heritable cellular lethality is determined and remote pathology is predicted from the number of morphoses and change in the sizes of colonies.

EFFECT: improved reliability of toxico-genetic estimation due to use of sensitive haploid strains, specific reactions of haploids and diploids when affected by weak doses of mutagens.

2 dwg, 1 tbl

FIELD: analytical methods in food industry and biotechnology.

SUBSTANCE: object of invention is to determine contents of cations, amines, anions of organic and inorganic acids in various media in food, alcoholic beverage and soft drink industries. Working electrolyte for electrophoretic determination of ions is composed of, mmole/L: histidine 25-35, 2-morpholinoethanesulfonic acid 100-140, a Crown ether 1.5-2.5, Triton X-100 0.02-0.50, and water - the rest.

EFFECT: enabled simultaneous determination of cations, amines, anions of organic and inorganic acids in various media.

7 ex

FIELD: medicine; ecology; hygiene.

SUBSTANCE: method can be used for analysis and differentiation of degree of pureness of water on purpose of revealing of effect of water onto human health, as well as for checking pureness of water in laboratory tests. Tested sample of water in amount of 2-5 ml is placed into dish of chemiluminometer. Flash is measured and ozone is supplied to dish through waterproof light-protected capillary gas-duct at speed of up to 10 mcg ozone/sec. Intensity and dynamic changes in chemiluminescence are measured during 1 minute. Computer automatically processes result of measurements and it is presented in form of graph of changes in chemoluminescence. Maximal signal (peak meaning) is calculated and total number of flashes is calculated within 1 minute (light sum of pulses during 60 seconds).

EFFECT: high sensitivity of method; reduced lower limit of measurement range; reduced amount of water necessary for tests.

1 tbl, 2 dwg

FIELD: environmental protection; methods of biotesting of the water on heavy metals pollution.

SUBSTANCE: the invention is pertaining to the method of the analytical biotesting of water. For the biotesting -cultivate the plants of the duckweed small Lemna minor L. at the permanent daylight and the temperature mode and the composition of the growth mineral medium. The biotesting duration makes 7 days. The toxicity degree is estimated through the mean day gain of the growth share of the duckweed small and compute it by the formula: D =(B-A)/A·t, where A is the initial number of the small leaves of duckweeds in the probe; B - the final number of the small leaves; t - growth time (in days). The number of the small leaves is counted in the probes on 2-d, 5-th and 7-th day of the test. Availability of the pollutants determine by the complex of the morphological changes of the duckweed. In the capacity of the morphological changes of the duckweed use the specific changes of the color of the young and mature plants with the characteristic localization on the small leaves, conservation of the groups of the duckweeds small leaves or their decay - partial or complete, conservation or dropping of the roots. The method allows to increase the information value of the water biotesting system.

EFFECT: the invention ensures the increased information value of the water biotesting system.

1 tbl

FIELD: medicine.

SUBSTANCE: method involves setting an invertebrate under test into controllable environment, irradiating it with infrared optical bandwidth radiation via transmitting optical fiber having its output end face placed on its rigid external cover heart zone, and optical radiation source making optical contact with transmitting optical fiber input end face. Reflected optical radiation is received with receiving optical fiber having its input end face located on rigid external cover of the invertebrate under test in heart zone. It is transformed into electric signal by means of the optical radiation receiver which makes optical contact with output end face of the receiving optical fiber. The received signal is transformed into digital codes, entered them into computer, codes digital filtration is carried out that is correlated with signal shape and frequency. Electric signal period values sample is calculated and saved. Method involves calculating sample dispersion or arithmetic mean of modulus of difference of each two electric sampled signal period values neighboring in time and an ecological hazard signal is sent when electric signal period sample dispersion threshold value or arithmetic mean of modulus of difference of each two neighboring in time electric sampled signal period values is violated. The system has computer and at least, one digital cardiac activity signal shaper. The shaper has in series connected cardiac activity transducer, transmitting and receiving optical fibers, optical radiation source and optical radiation receiver, amplifier and the analog-digital converter connected to computer input channel with its output channel. Cardiac activity transducer has casing having member for setting it on invertebrate body under test having rigid integument. Transmitting optical fiber input end face and receiving optical fiber output end face make optical contact to optical radiation source and to optical radiation receiver, respectively. The transmitting optical fiber output end face and receiving optical fiber input end face are turned in the same direction and separated in the casing with some distance, satisfying an inequality (πd2P)0.07 - 2.2 (1 / (πd2P))0.02≤R≤(πd2P)0.07 + 2.2 (1 / (πd2P))0.02, where R is the distance between a output end face of the transmitting optical fiber and input end face of receiving optical fiber, mm; Р is the optical radiation source power, mW; d is the transmitting optical fiber or reception optical fiber diameter, mcm.

EFFECT: increased reliability of environment control; wide range of functional applications; reduced price and simplification of system operation.

19 cl, 4 dwg

FIELD: analytical methods in environmental monitoring.

SUBSTANCE: invention relates to water toxicology and sanitary hydrobiology and can be used in estimation of toxicity of water when performing testing of effluent and natural fresh waters. Method envisages placing groups of mollusks (Viviparus viviparous L) in test (experimental) and pure (control) water to stand for a certain amount of time, after which lever of these mollusks is prepared and homogenized to obtain further extract of lever proteins, wherein activity of hydrolytic enzymes, acid phosphatase and DNAse, is determined. Toxicity of water is correlated with reliable change in total activity of test enzyme or at least one qualitative change in multiple forms in test variant relative to control.

EFFECT: achieved rapidity and versatility of method with respect to various toxicants and enabled detection of contamination of water with dangerous substances in concentrations from one tenth to hundred limiting permissible levels and higher.

5 dwg, 9 tbl, 7 ex

FIELD: heat-and-power engineering; other industries; installations for the scale formation analysis.

SUBSTANCE: the invention is pertaining to the scale formation analysis in the close to the industrial conditions at the controlled values of such parameters as the pressure and concentration of the salts in the working liquid. The installation for the scale formation analysis made in the form of the evaporation chamber includes: the installed with possibility of replacement heat-exchange system made in the form of the horizontal pipes with the electric heating elements located inside them, on which surfaces formation of the scale silt takes place; the system of feeding of the working liquid into the evaporation chamber and the mean for the steam condensation linked with the evaporation chamber by the steam withdrawal trunk. The installation is additionally supplied with the mean of the pressure control in the evaporation chamber, including the needle-type valve arranged in the steam withdrawal trunk and the system of withdrawal of the working liquid from the evaporation chamber including the needle valve mounted in the working liquid withdrawal trunk. The invention allows to expand the range of the conditions for analysis of the scale formation and to increase reliability of the analysis results.

EFFECT: the invention ensures expansion of the range of the conditions used for analysis of the scale formation and the increased reliability of the analysis results.

1 dwg

FIELD: environmental control, possible use at chemical weaponry elimination objects for estimating their influence on ecological situation in the region.

SUBSTANCE: first variant of the method for monitoring ecology of objects used for elimination of chemical weapons includes taking samples of surface, soil and underground water, snow cover, bottom sedimentations, soil, analyzing samples and processing the data, recording the results into analytical database, on basis of processing of analysis data, ecological situation is estimated in the region of object for storage and elimination of chemical weapons, in sanitary and protection zone and zone of protective measures, samples of atmospheric air are additionally taken, monitoring of flora and fauna in the region of chemical weaponry elimination object, in sanitary and protection zone, in protective measures zone is performed, all samples are compared to standards of maximal allowed concentrations of each certain substance, in case of exceeded maximal concentration in the air, analysis of water is performed, if maximal concentration in water is exceeded, analysis of soil is performed, if maximal concentration in soil is exceeded, fauna and flora is analyzed in the region of chemical weaponry elimination object, in sanitary and protection zone, in protective measures zone, as a result of comparison of resulting data, schedule of analysis operations is tightened, namely, times of analysis set in accordance to standards, while A≤(maximal allowed concentration)·α is considered a condition of normal environmental influence of an object, where A - result of analysis of samples of certain substance, α - maximal allowed concentration excess tolerance coefficient. In accordance to second variant, when the solution is determined before beginning construction of chemical weaponry elimination objects, in advance before construction of chemical weaponry elimination object is started, background monitoring is performed on territory assigned for construction of object, which monitoring includes taking samples of surface, soil and underground water, snow cover, bottom sedimentations, soils, and also samples of atmospheric air are additionally taken, and monitoring of flora and fauna is performed in the region of construction of chemical weaponry elimination object, in sanitary and protection zone, in protective measures zone, and after that the data resulting from background monitoring is compared to data, received in process of elimination of chemical weaponry, all samples are compared to standard maximal allowed concentrations of each certain substance, if maximal allowed concentration is exceeded in the air, analysis of the water is performed, if maximal allowed concentration is exceeded in the water, analysis of the soil is performed, if maximal allowed concentration is exceeded in the soil, analysis of flora and fauna is performed in the region of chemical weaponry elimination object, in sanitary and protection zone, in protective measures zone, as a result of comparison of received data, schedule of analysis operations is tightened, namely, analysis times set in accordance with standard times, processing of sample analysis data includes comparison of received data to background monitoring data, and as condition of normal environmental influence of object, following is considered: where A - result of analysis of samples of certain substance, Φ - result of background monitoring, δ < 0,1-0,2.

EFFECT: production of trustworthy estimate, possible prediction of influence of chemical weaponry elimination object on environment for operative making of decisions concerning possible emergency.

2 cl, 2 dwg

FIELD: organic chemistry, possible use when determining total organic pollution of surface, underground, drinking and industrial waters, and also for determining total amount of volatile compounds in these waters.

SUBSTANCE: in accordance to method for determining total organic pollution of water, a sample of water with organic pollution is taken, subjected to effect of ultraviolet radiation, in process of this effect, light absorption coefficient is measured, content of soluble iron is determined by means of chemical analysis and, if iron content does not exceed 0,15 mg/dm3, content of common organic carbon is calculated using formula C=k/a [%dm3/mg], where C - content of common organic carbon, mg/dm3; k - light absorption coefficient, %; a - experimentally calculated proportionality coefficient, characterizing connection between light absorption coefficient and content of common organic carbon at volumetric concentration of sample, having light absorption coefficient above 25% and content of soluble iron not above 0,15 mg/dm3.

EFFECT: simplification of realization, high objectivity of evaluation, high precision of measurements.

3 tbl, 1 dwg

FIELD: microbiology; ecology.

SUBSTANCE: method and device can be used for monitoring of water pools and ground waters, as well as for bacteriological inspection of water solutions and suspensions in medical, food and other branches of industry. Method of quantitative determination of microbiological pollution of water and water media is based upon selection of samples of tested medium, on letting it go through bactericide with formula R4NIn(n-1)/2)H2O, maximizing pH of sample to values of 5-6 units and determination of microbiological pollution of medium from concentration of iodine, extracted after interaction of sample of bactericide. Microbiological pollution of medium can determined as from iodine concentration in restored form of J-, and in oxidized form of J2. Device for realization of method has bactericidal filter connected with reaction chamber at output of which chamber the registrar is mounted.

EFFECT: improved sensitivity; improved truth of quantitative determination; reduced time of measurement.

6 cl, 3 ex, 4 tbl, 1 dwg

FIELD: analytical methods.

SUBSTANCE: invention is directed to provide a method for determining gold(III) in secondary raw materials and scraps, in natural materials, and in process solutions. When performing analysis, gold(III) is sorbed from hydrochloric acid solutions with ion-exchanger AB-17, on which rhodanine is preliminarily fixed via chemisorption, after which gold(III) is determined in solid phase.

EFFECT: increased reproducibility and accuracy in individual determination in the form of express-analyses due to fuller extraction gold from solutions thanks to increased sorption capacity.

1 tbl

FIELD: analytical methods.

SUBSTANCE: method of determining hydrogen sulfide and mercaptans in hydrocarbon gases in order to prevent corrosion of pipelines comprises sampling, consecutively introducing sample into reaction vessel with absorption solution of alkali metal carbonate to remove hydrogen sulfide and then into reaction vessel with absorption solution of alkali in ethyl alcohol to remove mercaptans, while simultaneously adding hydrochloric acid solution of p-phenylenediamine (photometric reagent) followed by adding auxiliary hydrochloric acid solution of ferric ions, stirring mixture with air flow to form uniform colored solution in each vessel, separately passing obtained solutions heated to 35-40°C to photometric detector, measuring signals from sample in photometric detector, and comparing measured signals with background signals.

EFFECT: simplified procedure and increased safety and information intensity of analysis.

4 cl, 3 tbl

FIELD: analytical methods.

SUBSTANCE: invention relates to analytical chemistry of platinum metals and may be used when determining palladium in refining production process nitrite solutions. Method comprises formation of colored complex compound of palladium(II) with nitroso-R-salt in solution in presence of sodium nitrite at pH 4-6, whereupon optical density of the complex at 520 nm is measured.

EFFECT: increased sensitivity and information value of analysis.

1 tbl, 3 ex

FIELD: analytical methods.

SUBSTANCE: invention relates to photometric determination of aluminum(III) in solutions of pure salts and artificial mixtures containing aluminum(III) in very low concentration. Method comprises transfer of aluminum(III) into complex compound with aluminon in low-acidic medium: to solution of aluminum(III) with pH 0-2 is added 100-120-fold amount of aluminon, 0.3-0.5 mL of surfactant solution containing 2% of gelatin solution, and water to 10 mL of total volume, after which resulting mixture is heated for 4-6 min on water bath at 80-98°C.

EFFECT: increased sensitivity and selectivity of analysis.

1 tbl

FIELD: analytical methods.

SUBSTANCE: group of inventions relate to photometric determination of iron(II) in solutions of pure salts and artificial mixtures containing iron (II) in very low concentration. First embodiment of invention comprises transfer of iron(II) into complex compound with aluminon in low-acidic medium. To that end, to solution of iron(II) with pH 2.2-7.0 is added 100-120-fold amount of aluminon, 0.3-0.5 mL of surfactant solution (obtained by adding 0.9 mL laurin alcohol to 7 g gelatin and completing the mixture with water to 120 mL), and water to achieve the total of 10 mL, after which resulting mixture is heated for 8-10 min on water bath at 80-98°C. In the second embodiment, iron(II) is transferred into complex compound with aluminon in low-acidic medium: to solution of iron(II) with pH 3.0-5.2 is added 10-15-fold amount of aluminon, 0.2-0.4 mL of surfactant solution containing 2% of gelatin solution, and water to 10 mL of total volume, after which resulting mixture is heated for 1-3 min on water bath at 80-98°C.

EFFECT: increased sensitivity and selectivity of analysis.

FIELD: analytical methods.

SUBSTANCE: quantitative determination of n,n-dimethylamido-o-ethylcyanophosphate is carried out using as color reagents solution of aromatic amine (o-tolydine) in bipolar aprotic solvent (acetone) and mixture of 30% hydrogen peroxide with 0.1 N sodium alkali taken at volume ratio 2:1, volume ratio of sample and color reagent being 25:1:1. Reaction mixture is prepared in the following order: sample + o-tolydine solution + hydrogen peroxide/alkali mixture. Thus prepared mixture is further subjected to photometric registration of reaction product at specified wavelength.

EFFECT: increased accuracy and sensitivity of analysis, simplified and accelerated analytic procedure.

3 tbl

FIELD: analytical methods.

SUBSTANCE: invention aims at determining gold(III) in aqueous solutions, in particular in effluents and production solutions. To that end, indicator composition for determining gold(III), which contains anionite AN-25 as sorbent, 2.0%, tin(II) as reagent, 10%, and water, sorbent is preliminarily saturated with gold(III) thiocyanate complexes.

EFFECT: enabled determination of gold(III) using harmless solvents and reduced determination time.

4 tbl

FIELD: analytical chemistry, possibly evaluation of chemical environment at spilling of missile fuel - non-symmetrical dimethyl hydrazone.

SUBSTANCE: method is realized with use of linear colorimetric process comprising steps of passing predetermined volume of analyzed air through indicating tube filled with inert carrier - silica gel with grains 0.25 - 0.4 mm wetted with reactive 0.1 - 1% solution of matter selected from group: selenious acid, silver nitrate, lead acetate and dried till loose state; then heating indicating tube till 50 - 60°C for 2 - 3 min and determining length of colored layer of indicating powder.

EFFECT: possibility for colorimetric determination of dimethyl hydrazone formaldehyde in air at predetermined concentration range.

4 notes, 9 dwg

FIELD: mechanical engineering.

SUBSTANCE: method comprises cleaning the surface, submerging the surface into the indicating composition, allowing the surface to stand in the composition for a time period, and visual or optical recording of the contrast of the indicating trace on the background of the surface to be tested in the visible radiation.

EFFECT: enhanced sensibility.

2 cl, 15 dwg, 1 tbl, 2 ex

FIELD: analytical chemistry, biology, toxicology, veterinary science.

SUBSTANCE: invention relates to a method for determination of N-(benzimidazolyl-2)-O-methylcarbamate in biological material. Method involves milling biological material sample, three-fold infusion with a mixture of solvent ethyl acetate-dichloroethane-formic acid taken in the ratio 5:5:1 (by volume), respectively, as an organic extractant, each time for 15 min. Prepared extracts are separated from solid particle of biological material, combined, combined extract is filtered and filtrate is extracted with 0.1 N hydrochloric acid solution. Prepared acid extract is washed out with ethyl acetate as hydrophobic organic solvent, ethyl acetate fraction is discarded, aqueous fraction is alkalinized with 10% sodium hydroxide solution to pH value 8-9 and extracted with ethyl acetate. Prepared extract is separated, dehydrated, extractant is evaporated and residue is dissolved in organic solvent (glacial acetic acid). Obtained residue is subjected for chromatography in silica gel thin layer treated with vaseline oil using a mixture acetonitrile-water (6:4) as a mobile phase. Chromatograms are developed in UV-light, analyzed substance is eluted from sorbent with a mixture solvents ethyl acetate-dichloroethane-formic acid (5:5:1) and optical density of eluate is determined at wavelength 282 nm. Method provides enhancing extraction degree, precision and sensitivity of assay. Invention can be used in practice of sanitation-epidemiology departments, chemical-toxicology and veterinary laboratories.

EFFECT: improved method of determination.

3 tbl, 2 ex

FIELD: analytical methods.

SUBSTANCE: invention is directed to provide a method for determining gold(III) in secondary raw materials and scraps, in natural materials, and in process solutions. When performing analysis, gold(III) is sorbed from hydrochloric acid solutions with ion-exchanger AB-17, on which rhodanine is preliminarily fixed via chemisorption, after which gold(III) is determined in solid phase.

EFFECT: increased reproducibility and accuracy in individual determination in the form of express-analyses due to fuller extraction gold from solutions thanks to increased sorption capacity.

1 tbl

Up!