SU877427A1 - Method of quantitative determination of 2-isoproxyphenil-h-methylcarbamate - Google Patents

Description

(54) METHOD FOR QUANTITATIVE DETERMINATION OF 2-ISOPROPYXENYL-N-METHYL-CARBAMATE

The invention relates to the analysis of pesticide residues in biological objects, and specifically to methods for determining 2-isopropoxyphenyl-N-methyl carbamate in food products. Quantitative determination of 2-isopropoxyphenyl-N-methylcarbamate, which is the active principle of pesticide preparations widely used in animal control, such as baigon, propoxylur, bolpho, is necessary for sanitary and hygienic control of food products, diagnosis of animal poisoning and regulation of pesticide use. drugs. A known method for determining carbamates by introducing functional groups possessing a solution to an electron into the composition of pesticide molecules or products of their destruction with a fuzzy definition by gas chromatography with. using an electron capture detector. To determine the 2-isopropoxyphenium of N-methylcarbamate, this method includes extraction of the pesticide and the use of the counter for the production of 2-hydroxyLenyl-m-methylcarbamate by hydrolysis of the pesticide, reacting the benzene of the obtained compound with trichloroacetylchloride, purifying the benzene oxychloride tricarboxyne hydrochloride, and treating the benzene by treating phosphate buffer and passing through a chromatographic column; determination of the electrophilic compound by gas chromatography with an eluting capture detector; l The residues of this method are the violation of the main structure of the analyte, which reduces the reliability and accuracy of the analysis / introduction of triethyl acetylchloride of an electrophilic organic substance into the sample, therefore, despite the complexity and difficulty of the purification used, the release of the benzene solution used for gas chromatographic determination is not achieved, from extraneous electrophilic substances, a large number of peaks are obtained on chromatograms. Closest to the present invention is a method that includes extracting an analyte, purifying the extract, and brominating without destroying the basic structure of the analytes in an acidic medium with an excess of bromide with PSH: followed by gas chromatography 23.

- The method includes the determination of highly volatile substances, therefore the bromination is carried out in solution. It is necessary to bind excess bromine by adding a compound to the sample, including one organic one, as well as extracting bromo derivatives, extracting and dehydrating it. This complicates the analysis and leads to contamination of the sample, which deteriorates the gas chromatographic determination.

The purpose of the invention is to simplify, increase reliability and accuracy of determination.

The goal is achieved by the fact that in the method of quantitative determination of 2-isopropoxyphenyl-L-methylcarbamate in biological solutions, preferably in milk, involving the extraction of the substance being analyzed, purification of the extract, bromination followed by gas chromatography, the bromination reaction is carried out with direct contact of the analyte with bromine a glass vessel with 2-isopropoxyphenyl-M-methylcarbamate adsorbed on its walls. filled with bromine vapors, after absorption of the vapors of the brrma by the analyte, its excess is removed by blowing the vessel,

Example. K20ml of milk in a centrifuge tube poured 60 ml of acetone. The contents are gently stirred with a glass rod and centrifuged for 5 minutes (rotor speed 2000 rpm) at 8.5. ExtpaiiT is drained. If necessary, filtered through a WIDE GRAPPING paper filter. The acetone from the extract is distilled off in a rotary vacuum evaporator at a pressure of 300 mm Hg. Art. within 5 min The aqueous residue is transferred to a separatory funnel, 10 ml of a mixture of diethyl ether and hexane (9: 1) are added and the contents are shaken for 1 minute (80-60 shakes). The layers are allowed to separate. The bottom layer is slitsiot and discarded. 0.7 g of anhydrous sodium sulfate and is added to the ether-hexane extract. leave for 5 minutes, stirring the contents periodically. The dehydrated extract is poured into a conical centrifuge tube, into which a capillary, sealed in the upper part, is then placed. The lower part of the tube is immersed in a water bath. The solvent is evaporated at boiling () to a volume of 0.7 ml. The residue is applied to the Silufol plate with a syringe or pipette strip (not exceeding a width of 8 mm) | along the starting line (20 mm from the edge of the plate). The tube is washed with 0.3 ml of dichloric ether, which is also transferred onto a plate. After drying

solvents, the plate is placed in a chromatographic chamber, at the bottom of which a mixture of hexane and acetone (5: 7) is preliminarily poured in a layer of 7 ml. Chromatography is carried out at. When the solvent rises on a thin layer, not reaching 10 mm of the top edge of the plate, the latter is removed from the chamber. The R 2-isopropoxyphenyl-N-methylcarbamate is 0.75 under these conditions of chromatography. Based on this, a strip of a plate 20 mm wide with a pesticide localization zone is cut out. The central line of this band should correspond to the central line of the pesticide localization zone, calculated on the basis of RP. The strip of the plate with the substance being analyzed is cut into pieces of 0.4-0.6 cm, placed in a glass tube (volume 5 ml) and poured over 3 ml of acetone. The bux is closed with a lid and incubated for 30 minutes with occasional agitation of the contents. Then the acetone solution is filtered into a clean tube. The solvents are evaporated to dryness. Blowing dry clean air or nitrogen into the tube.

The bottle is filled with bromine vapor of dark brown color, filling the last of the flask with high shoulders, at the bottom of which there is a small amount (6 ml) of liquid. The bottle will be closed with a lid and placed in the refrigerator at

5-8 C. After 2 h, the bux is removed. Excess bromine vapor is removed by briefly blowing the cups with dry clean air or nitrogen. In the tube pour 2 ml of acetone. Shaking the bottle, wash its inner surface. 2-4 µl of this solution is injected into the chromatograph.

Chromatographic conditions.

Claims (2)

Color-106 chromatograph with constant recombination rate detector. The speed of the tape recorder 200 mm / h. The working scale of the electrometer is 1 X S, the column length is 1.0 m, the internal diameter is 3 mm. The column is filled with N-AW chromaton granulated with 0.2000, 250 mm with 5% S 30 silicone. Temperature conditions: evaporator 250, column 200 and detector 210c. The flow rate of the carrier gas (nitrogen) through the column is 35 ml / min, the detector 75 ml / min. The retention time of the brominated pesticide is 4.00 min. VETT 0.8 mm. The linearity of detection is observed in the range from 0.05 to 2.8 gig pestiid. If the peak height occupies more than 78% of the paper width of the samopisk, dilution of the brominated pesticide is allowed. The lower limit of the pesticide determination is 0.002 mg / kg. Removing pesticide additives from product samples 72%. TeiKHM samples, the proposed method, allows us to simplify, increase the reliability and accuracy of determination, as they obtain a quantitative yield of one bromine-containing compound — on the chromatograms, in addition to the solvent peak, only one peak of bromo derivative 2-eopropoxyphenyl-M-methylcarbs is obtained. The application of the proposed method allows to improve the sanitary and hygienic control of food products, regulate the use of pesticide, and more reliably diagnose animal pickling. The claims of the method for quantitative determination of 2-isopropoxyfelnyl-N-methylcarbamate in biological solutions, preferably in milk, providing for the extraction of the analyzed substance, purification of the extract, bromination followed by geochromatography, characterized in that, in order to simplify, improve the reliability and accuracy of the analysis , the bromination reaction is carried out by direct contact of the analyte with bromine in a glass vessel with 2-isopropoxyphenyl M-methyl adsorbed on its walls arbamatom,. filled with bromine vapors, after absorption of bromine vapors by an anesthetized substance, its excess is removed by blowing the vessel. Sources of information taken into account in the examination 1.Stanley C.W., Thornton J .S. Gaschromatograghlc method for the rest of the baygon and 1st ma lor metabo1 i te In animal tissues and mtlk.J. Agr. food chem., 1972, 20, 6, 1269-1273. 2. USSR author's certificate number 567132, cl. G 01 N 31/08, 1977 (prototype).