Method of detecting tetraethyl thiuram disulphide in blood

FIELD: chemistry.

SUBSTANCE: sodium fluoride is added to an analysed sample in amount of 10% of the mass of the biological object and infused twice in 45 minutes with portions of ethyl acetate, the mass of each of which is twice higher than the mass of the biological material. Separate extractions are combined, filtered through anhydrous sodium sulphate. The solvent from the filtrate is evaporated at temperature 50-60°C. The residue is dissolved in a mixture of hexane-dioxane-propanol-2 solvents. Chromatography is performed in a column with silica gel L 40/100 µ using a hexane-dioxane-propanol-2 mobile phase. The eluate fractions which contain the analysed substance are merged. The eluate is evaporated. The residue is dissolved in a mixture of hexane-dioxane-propanol-2 solvents and the analysed substance is determined via high performance liquid chromatography (HPLC) in a 64x2 mm column filled with Silasorb 600 sorbent using a hexane-dioxane-propanol-2 mobile phase and a UV detector.

EFFECT: invention shortens the duration of detecting tetraethyl thiuram disulphide in blood and increases its sensitivity.

3 tbl, 2 ex

 

The invention relates to biology, chemistry and toxicology, and in particular to methods of determining tetraethylthiuramdisulphide in the blood, and can be used in the practice of chemical-Toxicological and clinical laboratories. The method refers to the mass number.

There is a method of determining tetraethylthiuramdisulphide in biological material (tissues, organs), which consists in processing a biological sample approximately equal to the mass amount of the mixture of hexane and chloroform, taken in a volume ratio of 6:4, for two hours, separating the resulting extract, chromatographicaliy column filled with anhydrous sodium sulfate and silica gel using the mobile phase hexane-chloroform (6:4 by volume), the process of evaporation of the total volume of the eluate to the solids handling balance in sulfuric acid medium with a solution of hydroquinone, and then a solution of copper acetate followed by measuring the optical density of the resulting colored solution in the region of wavelengths 400-420 nm (Mazanowski AB, Fartusi A.F., Sedov, A.I., Bacn have Viznachennya the teturama i turama influence materal // Farmaceutyczny magazine. - 1979. No. 2. - P.54-57).

The method is characterized insufficiently high sensitivity, low selectivity, relatively low accuracy.

There is a method of determining tetraethyltin is amisulpride in blood by soaking the sample for 12 hours with a twenty-fold (by volume) the amount of a solvent mixture of ethanol-ether, taken in a volumetric ratio of 1:1, separating the resulting extract from the biomaterial by filtration, evaporation of the filtrate to dryness in vacuum distillation, dissolving the residue in carbon tetrachloride, treatment with a solution of iodide of copper within half an hour of shaking, centrifugation of the reaction mixture, followed by spectrophotometric determination at a wavelength of 430 nm (Galuskina I.D., Filov VA Transformation and definition of industrial organic poisons in the body. - L.: Chemistry, 1971. - S-226).

The method is characterized by the duration of the run, not enough high selectivity and sensitivity.

The closest is the way to determine tetraethylthiuramdisulphide in the blood, based on the fact that the analyzed sample was infused for 12 hours with a twenty-fold (by volume) the amount of a solvent mixture of ethanol-ether, taken in a volumetric ratio of 1:1, the obtained extract is separated from the blood by filtration, the solvent of the filtrate is evaporated at a temperature not exceeding 60°C to obtain a dry residue, the residue is dissolved in chloroform, the chloroform solution onto the plate with a thin layer of sorbent, chromatographic, using a mobile phase of chloroform-carbon tetrachloride (3:1), the chromatogram shown by processing the surface of the sorbent 10% solution of copper sulfate with subsequent ODA is a division of the analyte in the form of colored complex with copper ions densitometric method (Egorova NM Densitometric determination teturama in blood // Materials of conference of young scientists 1 MMI (1-St Moscow medical Institute. Sechenov). - M., 1972. - Part 1. - P.87-88).

The method offers a significant amount of time on the process definition and not high enough sensitivity.

The objective of the invention is to reduce the duration of the determination and improvement of its sensitivity.

This object is achieved by using the proposed method, which consists in the fact that the analyzed sample is added sodium fluoride in amount of 10% by weight of a biological object, the mixture twice for 45 minutes insist with portions of ethyl acetate, each of which is twice the mass exceeds the mass of biological material, the extracts combined filtered through anhydrous sodium sulfate, the solvent of the filtrate is evaporated at a temperature of 50-60°C, the residue is dissolved in a solvent mixture of hexane-dioxane-propanol-2 (40:5:1 by volume), chromatographic in the column silica gel L 40/100 µ using the mobile phase hexane-dioxane-propanol-2 (40:5:1 by volume), fractions of the eluate containing an analyte, unite, eluent is evaporated, the residue is dissolved in a solvent mixture of hexane-dioxane-propanol-2 (15:5:1 by volume) and spend the determination analyzed with the unity of the HPLC column of dimensions 64×2 mm, filled with sorbent Silsor 600" using the mobile phase hexane-dioxane-propanol-2 (15:5:1 by volume) and UV - detector.

The method is as follows: to a biological sample containing tetradecyltrimethyl, add sodium fluoride, the weight of which amounts to 10% by weight of a biological object, twice for 45 minutes insist with portions of ethyl acetate, the mass of each of which is twice the mass of biological material, the extracts combined filtered through anhydrous sodium sulfate, the solvent is evaporated from the filtrate at a temperature of 50-60°C, the residue is dissolved in a solvent mixture of hexane-dioxane-propanol-2 (40:5:1 by volume), making a column of silica gel L 40/100 µ, with chromatographic by using the mobile phase hexane-dioxane-propanol-2 (40:5:1 by volume), fractions of the eluate containing an analyte, unite, eluent is evaporated, the residue is dissolved in a solvent mixture of hexane-dioxane-propanol-2 (15:5:1 by volume) and spend the definition of the analyzed compounds by HPLC column of dimensions 64×2 mm, filled with sorbent Silsor 600" using the mobile phase hexane-dioxane-propanol-2 (15:5:1 by volume) and UV-detector.

Example 1

Definition tetraethylthiuramdisulphide in uncured human blood

In 10 g of canned blood of man the ESA contribute 10 mg tetraethylthiuramdisulphide, carefully mix the biological fluid with the substance and leave for 1.5 hours at a temperature of 18-20°C. after the specified time to the biological object containing an analyte, add 1 g of sodium fluoride, the resulting mixture is stirred for 2 minutes, then pour 20 g of ethyl acetate and incubated for 45 minutes with occasional stirring. The extract is separated from the biological material, and the operation processing is repeated in these conditions. Separate hoods combine, filtered through a glass filter with a diameter of 4 cm with a layer of anhydrous sodium sulfate height of 1-1,5 cm Filter additionally washed with 10 g of ethyl acetate. The filtrate and wash liquid unite, evaporated to a dry residue in a stream of air heating in a water bath at 50-60°C. the Residue is dissolved in 2-3 ml of the solvent system hexane-dioxane-propanol-2 (40:5:1 by volume). The resulting solution contribute to column dimensions 490×11 mm, filled with 10 g of silica gel L 40/100 µ. After full entry of the solution into the layer of sorbent in the column add eluent - solvent system hexane-dioxane-propanol-2 (40:5:1 by volume).

Emerging from the column eluate is collected in separate fractions of 2 ml each. Fractions 9 to 16, inclusive unite in varicellae Cup, eluent is evaporated in a stream of air on which revane at 50-60°C in a water bath, the residue is dissolved in 10-15 ml of dioxane, quantitatively transferred into a volumetric flask with a capacity of 25 ml and bring the contents of the flask dioxane to the mark (solution A). 2.5 ml of the solution And contribute in a volumetric flask with a capacity of 25 ml, there was added 2.5 ml of dioxane, 1 ml of propanol-2, 15 ml of hexane and bring the contents of the flask to the mark with a mixture solvent of hexane-dioxane-propanol-2 (15:5:1 by volume) (solution B). 8 μl of solution B are injected type "milikhrom".

Chromatographic by HPLC. The process of chromatography was carried out is carried out in a column of size 64×2 mm, filled normalnotorowym sorbent "Selasar 600" using the mobile phase hexane-dioxane-propanol-2 (15:5:1 by volume) and UV-detector.

The feed rate of eluent is 100 ál/min, scale registration of 0.8 units of optical density, the measurement time of 0.6 sec. The optical density recorded at a wavelength of 276 nm.

The peak on the chromatogram with time holding was 4.42 min (retention 442 μl) corresponds to tetraethylthiuramdisulphide.

The quantitative content of tetraethylthiuramdisulphide determined on the basis of the chromatographic peak area by the equation of the calibration graph and count on a portion of the substance introduced into the uncured blood.

Preparation of calibration graph.

In a series of volumetric flasks with a capacity of 10 ml make 0,25 0,5; 1,0; 2,0; 4,0; 5,0 ml of 0.01% solution of tetraethylthiuramdisulphide in a solvent mixture of hexane-dioxane-propanol-2 (15:5:1 by volume) and bring to the mark with a mixture solvent of hexane-dioxane-propanol-2 (15:5:1 by volume). 8 μl of each of the obtained solutions are injected. The chromatography was carried out is carried out in a column of size 64×2 ml, filled with sorbent Silsor 600"using the mobile phase hexane-dioxane-propanol-2 (15:5:1 by volume) and a UV detector. The feed rate of eluent is 100 ál/min

The scale registration of 0.8 units of optical density, the measurement time of 0.6 sec. The optical density recorded at a wavelength of 276 nm.

According to the results of measurements on the chromatograph build a graph of the dependence of chromatographic peak area against the concentration of the detected substance. Linear within the concentration range of 0.02-0.40 to ug.

By the method of least squares to calculate the equation of the calibration graph, which in this case is:

S=10,61051·C+0,03288,

where S is the area of the chromatographic peak, C is the concentration of analyte in khromatograficheskoi sample, ág.

The results of quantitative determination of tetraethylthiuramdisulphide presented in table 1.

Example 2

Definition tetraethylthiuramdisulphide in human blood, canned perlucidum

In 10 g of human blood, conservitave the major perlucidum, make 10 mg tetraethylthiuramdisulphide, carefully mix the biological fluid with the substance and leave for 1.5 hours at a temperature of 18-20°C. after the specified time to the biological object containing an analyte, add 1 g of sodium fluoride, the resulting mixture is stirred for 2 minutes, then pour 20 g of ethyl acetate and incubated for 45 minutes with occasional stirring. The extract is separated from the biological material, and the operation processing is repeated in these conditions. Separate hoods combine, filtered through a glass filter with a diameter of 4 cm with a layer of anhydrous sodium sulfate height of 1-1,5 cm Filter additionally washed with 10 g of ethyl acetate. The filtrate and wash liquid unite, evaporated to a dry residue in a stream of air heating in a water bath at 50-60°C. the Residue is dissolved in 2-3 ml of the solvent system hexane-dioxane-propanol-2 (40:5:1 by volume). The resulting solution contribute to column dimensions 490×11 mm, filled with 10 g of silica gel L 40/100 µ. After full entry of the solution into the layer of sorbent in the column add eluent - solvent system hexane-dioxane-propanol-2 (40:5:1 by volume). Emerging from the column eluate is collected in separate fractions of 2 ml each. Fractions 9 to 16, inclusive unite in varicellae Cup, eluent and paraut in air flow under conditions of heating at 50-60°C in a water bath, the residue is dissolved in 10-15 ml of dioxane, quantitatively transferred into a volumetric flask with a capacity of 25 ml and bring the contents of the flask dioxane to the mark (solution A). 2.5 ml of the solution And contribute in a volumetric flask with a capacity of 25 ml, there was added 2.5 ml of dioxane, 1 ml of propanol-2, 15 ml of hexane and bring the contents of the flask to the mark with a mixture solvent of hexane-dioxane-propanol-2 (15:5:1 by volume) (solution B). 8 μl of solution B are injected type "milikhrom".

Chromatographic by HPLC. The process of chromatography was carried out is carried out in a column of size 64×2 mm, filled normalnotorowym sorbent "Selasar 600" using the mobile phase hexane-dioxane-propanol-2 (15:5:1 by volume) and UV-detector.

The feed rate of eluent is 100 ál/min, scale registration of 0.8 units of optical density, the measurement time of 0.6 sec. The optical density recorded at a wavelength of 276 nm.

The peak on the chromatogram with time holding was 4.42 min (retention 442 μl) corresponds to tetraethylthiuramdisulphide.

The quantitative content of tetraethylthiuramdisulphide determined on the basis of the chromatographic peak area by the equation of the calibration graph and count on a portion of the substance introduced into the blood, the canned perlucidum.

Preparation of calibration graph and its equation are shown above in the example is 1.

The proposed method is compared with the prototype 3 times reduces analysis times, 250 times increases the detection sensitivity in khromatograficheskoi sample and 2.5 times in the blood. Comparative characteristics of the proposed and known methods are presented in table 3.

Table 3
Comparative characteristics of the proposed and known methods (for example, research uncured human blood)
IndexThe proposed methodThe known method
1. Duration definition4-4,5 hours13-14 hours
Cavalletti (open minimum):
in khromatograficheskoi sample0.02 μg5 mcg
b) 100 g of a biomaterial0.2 mg0.5 mg
3. Interval LINEST is STI calibration graph 0,02-0,40 mcg5-60 mcg
4. The degree of extraction of the analyzed compounds from biological material92,93%About 80%

Method for determination of tetraethylthiuramdisulphide in the blood, which consists in the fact that the analyzed sample insist with an organic extractant, the obtained extract is separated from the biological material, evaporated at a temperature not exceeding 60°C to obtain a dry residue, the residue is dissolved in an organic solvent, chromatographic and determine an analyte chemical method, characterized in that the analyzed sample before infusion is treated with sodium fluoride, the weight of which amounts to 10% by weight of a biological object, insisting samples are twice for 45 min portions of ethyl acetate, the mass of each of which is twice the mass of the biological object obtained removing before evaporation was filtered through a layer of anhydrous sodium sulfate, the dry residue obtained after evaporation of the filtrate, is dissolved in a solvent mixture of hexane-dioxane-propanol-2 (40:5:1 by volume), chromatographic column with silica gel L 40/100 µ using the mobile phase hexane-dioxane-propanol-2 (40:5:1 by volume), fra is tion of the eluate, containing an analyte, unite, eluent is evaporated, the residue is dissolved in a solvent mixture of hexane-dioxane-propanol-2 (15:5:1 by volume) and carry out the determination of an analyte by HPLC column of dimensions 64×2, filled with sorbent Silsor 600" using the mobile phase hexane-dioxane-propanol-2 (15:5:1 by volume) and a UV detector.



 

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