The method of determining the toxicity of 1-nitrosoamines in food

 

(57) Abstract:

The invention relates to the field of analysis of the safety and hygiene of food products and food raw materials, namely, to determine the toxicity of 1-nitrosoamines in food products by the method of inverse gas chromatography. Selected samples are sterilized by exposure to x-ray radiation, mix crushed and gomogenizirovannogo the sample with a glass solid carrier, passed through a chromatographic column eluent consisting of immiscible with moisture samples pentane distilled water azeotrope from the extract and subsequent circulation of eluent serves extract in a capillary chromatographic column, the inner surface of which is modified hydrophobic layer C16at a constant temperature in the range of 30-40°C, sequentially injected a mixture of saturated cyclic and aromatic hydrocarbons in column coated with a breakdown of the amount nitrosoamines and additives dimethyl - and diethylnitrosamine with known mass, determine the magnitude of the retention key a couple of hydrocarbons with the same number of carbon atoms in the sample and supplements, identify the presence of chromatographic zones nitrosoamines on velichestvennoi the total content of nitrosoamines to determine toxicity by comparing with the hygienic standard. Improved the reliability of determination of toxicity nitrosamines in food. 1 PL.

The invention relates to the field of determining the safety of food raw materials and food products, namely, to determine the toxicity of 1-nitrosoamines () chromatographic method.

One of the known methods for determining the toxicity of 1-nitrosoamines is a technique in which selected laboratory sample weight up to 300 g or up to 300 cm3store in the freezer in the temperature range from -8° -18°C for 1-3 days, after which the sample is ground in a meat grinder or in a homogenizer, transferred into a round bottom flask, fitted with devices for steam distillation, and to the product add the required amount of vicariates, aliquot volume of a solution of sulfanilic acid, aliquot volume of 1 n sulfuric acid to bring the pH of the sample is equal to 3, add to the sample 1 cm3hexane solution of internal standard, which is used as 1-nitrosodipropylamine. Then distilled volatile products with water vapor, collecting 200-250 cm3of distilled water, and then extracted with 4 to 5 times ON portions of fresh dichloromethane. Nigeria losses 1-nitrosoamines, the total filtrate is evaporated in a round bottom flask with a capacity of up to 150 cm3equipped with a reflux condenser to 5-7 cm3at a temperature of not more than 65°C, passing a small current of inert gas through the concentrate volume. Washed reflux 2 cm3hexane and the sample is evaporated to 1-2 cm3. The resulting concentrate is subjected to dinitrothiophene adding 1 cm32-3% solution of bromovalerate in acetic acid and extract samples for 30 min at room temperature, and the solution was evaporated to dryness on a rotary evaporator at a temperature not exceeding 50°C and a vacuum of at least 15 mm RT.article The residue is neutralized with sodium hydrogen carbonate solution to pH 8 and add aliquot volume of alcoholic solution of 8-methoxy-5-chinaincorporated (KAZ) and boiled for 30 minutes under reflux at a temperature of 100°C., the mixture is evaporated to dryness, and the residue is dissolved in 0.3-0.5 cm3of ethanol. The resulting solution was analyzed by thin-layer chromatography in comparison with the standards, which use 8-methoxy-5-[N-(2-N-diethylamino)]chinaincorporated derivatives amine, diethylamine, dipropylamine with a concentration of 2 mg/cm3. For holding the blank sample to the second part A sodium, boil for 30 min and treated similarly analyzed sample. The resulting alcoholic solution is also analyzed by thin-layer chromatography, the results of which take into account when calculating the content. For carrying out thin-layer chromatography to the starting line put 10 points, at which place from 20 to 30 ICSM3the sample and standard solutions with different concentrations. The plate is placed in a chamber for chromatography and elute with a mixture of benzene - ethyl acetate - acetic acid in the ratio of 100:50:1 until the solvent front upper edge of the plate, which is removed from the chromatographic chamber, dried for 15 minutes, cut 2 cm plate below the front of the solvent to remove lipophilic impurities. Plate re chromatographic in a mixture of acetonitrile - concentrated aqueous ammonia solution in the ratio of 9:1 until the solvent front upper edge of the plate, which is removed from the chromatographic chamber, dried for 15 min and again placed in a chromatographic chamber with the initial solvent system. After preparation of the chromatographic plate of her show in ultraviolet radiation and conduct qualitative and quantitative is roizvodnykh ON and the intensity of fluorescence of the sample, blank tests and solutions with different concentrations of fluorescent derivatives using fluorimetry at a wavelength of excitation of 340 nm and 480 nm fluorescence. Determine the toxicity in the food product by comparing the total content with the acceptable daily intake (ADI) in the range of 0.002-0.004 mg/kg for raw and smoked products.

The method is characterized by insufficient accuracy of determination in connection with the use as an internal standard dipropylenetriamine, surface activity is more than 100 times the surface activity dimethylnitrosoamine, and largest extract of which is determined by the total degree of extraction ON the sample [USSR Author's certificate No. 1157449, 1985].

There is a method of determining the toxicity of volatile in foods by high-performance liquid chromatography with fluorescence detection, in which the selection was made volatile by distillation with steam and extraction of volatiles ON from the condensate does not differ from the above analogy, and to simplify dinitrothiophene add aliquot volume of a mixture of 30% Hydrobromic and glacial acetic acid, incubated for 30 min at kankam3buffer solution with a pH of 10.5 and enter 100 ICSM3solution of 5-[amine]naphthalene-1-sulfochloride with a concentration of 1 mg/cm3mix the contents and incubated for 40 min at a temperature of 40°C. then add 100 ICSM31,5 N. hydrochloric acid, stirred and chromatographic through column chromatography (h mm), filled with sorbent ZORBAX ODS (5 μm) with a flow rate of eluent 150 ICSM3/min, which use a mixture of acetonitrile-water 2:1. The sample injection is carried out with the help of the hinge type Readin of 10 ICSM3as a detector use “Fluorat of 0.2-2M with a maximum excitation and emission 350; 530 nm, respectively. To determine the qualitative and quantitative composition also use nitrosodipropylamine as an internal standard, and the toxicity is determined by comparison of the total content ON hygienic standard [Zhur. analytical chemistry, 2001, T. 56, No. 4, S. 407-411].

The method is characterized by the insufficient reliability of definition due to the lack of separation dimethylnitrosoamine from cyclic and heterocyclic nitrosoguanidine, and also a low degree of extraction, for low molecular weight component with a content of 0.2-0.8 Dstline toxicity in foods by gas chromatography, based on the selection of samples of food raw materials, food and feed by steam distillation and subsequent extraction with dichloromethane from aqueous distillate and concentration of the extract to 1 cm3in accordance with the above algorithm. Analysis of the extract is carried out by gas chromatography by entering the sample volume 1-10 ICSM3in the evaporator chromatograph heated to a temperature of 220°C, the separation of the glass column of 3 m long and 2 mm diameter, filled with chromatone N-AW-DMCS with applied as a stationary phase 15% carbowax-20M, at the same time as the carrier gas is nitrogen (O. S. o'clock) or argon at a speed of 20 cm3/min at the temperature of the column under isothermal conditions, is equal to 125°C. the detector used chemiluminescent thermal analyzer with temperature catalytic oven to 450°C, nitrogen flow of 40 cm3/min under oxygen pressure up to 0.6 MPa. Qualitative analysis of the sample are carried out by the retention time of the standard substances, which use 1-nitrosopropane amine, diethylamine, dipropylamine and quantitative determination of the sample by comparing ve is philamina with a concentration of 0.2 µg/cm3in hexane. The toxicity of nitrosoamines in the sample is determined by comparison with the hygienic standard [MUK 4.4.1.011-93 chemiluminescent method for the determination of 1-nitrosamines in food staples raw materials and food products (reference method analysis), FZGSEN, 22.12.1993].

The method is characterized by a systematic error that is associated with a low degree of extraction of the samples AT various buildings reaching for the low molecular weight amines 60-70%. In addition, the introduction unstable in the evaporator with high temperature leads to thermal decomposition and oxidation to nitroamines and other unidentifiable products, as a result of the low reliability of the determination. The introduction of a small amount of sample extract in the chromatographic system from 1 to 10 ICSM3leads to a distortion of the qualitative and quantitative composition carcinogenic in laboratory sample compared to their content in the selected sample of food raw materials and food products.

The objective of the invention is to increase the reliability of toxicity in the sample of food.

The problem is solved in that the selected sample food from the Ute with crushed glass solid carrier, fill the mixture chromatographic column for liquid chromatography, is provided in the upper part of the water-cooled reflux condenser for condensing volatile solvents and a nozzle for introducing a component of the mobile liquid phase and to separate the water from the hydrocarbon solvent. In the lower part of the column contains a sealed glass membrane for the separation of solid dispersed particles of the product from the liquid dispersion medium. Column attached to a two-neck round-bottom glass flask, fitted in the lower part of the valve and having a wide receiver for receiving vapors in the upper part of the column with water reflux condenser, providing condensation and the flow of fluid into the upper portion of the chromatographic column. In the chromatographic column gradually make pentane, the volume of which take on the basis of the humidity of the sample and the content of the pentane in azeotropic mixture with water (1.4 wt.%), when filling bulb extract 1/4 of its volume is heated before entering the condensate in the nozzle for the Department of water, with the subsequent transfer of the hydrocarbon component of the condensate in the chromatographic column. After receiving drained of the eluate from the chromatographic Colo 25 m long with a modified application of the hydrocarbon layer inner surface, placed in thermostat at the temperature of the processes of life (30-40°C) chromatograph equipped with a flame ionization detector. Sputtering is performed by applying helium capillary column with a given flow rate of the carrier gas during the time required for stopping the change of the zero line signal detector. Then periodically injected into the column, the sample is saturated cyclic and aromatic hydrocarbons in quantities necessary to determine the levels assumed IN weight from 1 to 100 μg, and determine the retention time of individual hydrocarbons (cyclohexane, methylcyclohexane, benzene, toluene and ethylbenzene) at the constant speed of the carrier gas from 0.1 to 0.2 cm3/min. After which characterize the chromatographic area ratio of the corrected retention times of aromatic hydrocarbons to saturated cyclic hydrocarbons with the same number of carbon atoms.

Detection zone with characteristics within range of the chromatographic parameters of the retention of hydrocarbons in ON, stop the flow of the eluate by means of a crane at the bottom of the flask, and the qualitative and quantitative determination of the current is isoprostane dimethylamine and diethylamine in hexane.

The method is as follows.

A portion of food raw materials weighing up to 1 kg, to prevent the growth of microorganisms and changes the content, process x-rays, seal vacuum packaging until the time of sample preparation and stored in the refrigerator. For sample preparation the sample is ground in a meat grinder, frozen and then homogenized using a mill. Mix dispergirovannoyj sample in the form of paste with glass chips or round glass ball the size of 5-10 mm, fill the mixture chromatographic column for liquid chromatography, located vertically on the working plate vibrator. Column provided in the lower part of the glass membrane, and in the upper part of the water-cooled reflux condenser and a nozzle, allowing both to separate water from hydrocarbons, and using a dropping funnel to introduce the required amount of eluent. When this column is attached to the lower part to a two-neck round-bottom glass flask heated and soldered in the lower part of the valve and having a wide receiver for receiving vapors in the upper part of the column. An addition funnel filled with pentane, and eupalinos funnel with such speed, to ensure smooth flow of extract in a round bottom flask. When filling bulb extract 1/4 part of the volume, it is heated before entering the condensate in the nozzle for the Department of water, with the subsequent transfer of the hydrocarbon component of the condensate in the upper part of the chromatographic column. After the onset of the stationary mode chromatographic extraction anhydrous extract sent via atomizer through the lower valve into the capillary column, which is thermostated at a temperature of 30°C and is located in thermostat chromatograph equipped with a flame ionization detector. The spraying of the extract is performed by the flow of helium within the time required to stop the drift of the zero line signal detector. Then periodically introducing a sample of methane, cyclohexane, methyl-, ethylcyclohexane, benzene, toluene, ethylbenzene in the capillary column with the division of the flow (1/20-1/100), which allows to reduce size of the sample hydrocarbons interacting with the sample extract to a value of infinite dilution. Determine given with respect to methane retention time of components in the mixture at a constant rate of carrier gas from 0.1 to 0.2 cm3/min. retention time of benzene and cyclohexane, or toluene and methylcyclohexane, or ethylbenzene and ethylcyclohexane when matching these characteristics with predefined parameters nitrosopropane volatile amines stop the flow of the eluate by means of a crane at the bottom of the flask, injected sequentially into the sprayer standard solutions of NDMA and nitrosodiethylamine with a concentration of 500 µg/cm3in the amount of 1 mg of the analyte to determine the retention times of key-value pairs cyclic and aromatic hydrocarbons optimal for determining retention. Build the dependence of the logarithm of the relations holding key-value pairs cyclic and aromatic hydrocarbons from the number of CH-bonds in standard and approximation on the y-axis determine the contribution of microtomography in the relative retention arenes, which is the qualitative characteristic of toxicity. Determine the number of CH-groups in the sample ON the toxicity of equal toxicity nitrosopropane aliphatic amines, by the dependence of the logarithm of the relations holding cyclic and aromatic hydrocarbons in the standard aliphatic ON the number of CH-bonds to the substituents. Quantitative determination of the amount of the sample pexeva is of key pairs, closest to the analyzed sample. Toxicity is determined by comparison of the contents sum TO the sample per unit mass of the sample in terms of nitrosopropane amine with the same parameters hold arenes and hygienic standard.

Presents a set of stated characteristics are provided by the solution of the invention:

- sterilization of x-ray selected sample and its sealing prevents the formation of exogenous;

- chromatographic extraction amount of the homogenized sample of the food product eluent consisting of immiscible with each other components (water and pentane) binary solvent, allows the separation of the more polar ON from fats and other volatile ingredients components food products;

- azeotropic distillation of the obtained extract gradually changes the polarity of the mixed extractant in the process of chromatography was carried out by separating the water in the nozzle and provides an increase in the hydrophobicity of eluent to displace polar ON from the chromatographic column;

- spraying anhydrous extract in a capillary chromatographic column thermostated at the temperature effective to adsorb the sample ON the surface of the partition page-carrier gas in the column, that enables a separation of key pairs saturated cyclic and aromatic hydrocarbons to assess the toxicity of samples;

- finding the value retention of a key pair saturated cyclic and aromatic hydrocarbons in the analyzed sample and nitrosopropane dimethyl - and diethylamino allows to determine the contribution of isonitrogenous and the number of CH-bonds for nitrosoamine equal toxicity summary toxicity ON in the analyzed sample of food products;

- determining values for retention arenes in the sample and with the logarithm of the retention of a key pair that is closest to the analyzed test allows to quantitatively find the content amount in the sample of food products;

- a comparison of content amount per unit weight of food in terms of nitrosopropane amine with the same parameters hold arenes and hygienic standard allows you to more reliably determine the toxicity in the analyzed sample.

Thus, the sterilization sampled exposure to x-rays, extraction and separation amounts nitrosoamines from a homogenized sample of pixelogic of immiscible with moisture food product with pentane, azeotrope the water distillation from the extract of the circulation pentane along the length of the chromatographic column to complete drying, spraying anhydrous extract in a capillary chromatographic column with a modified application of the hydrophobic layer inner surface, defining a retention time of key pair saturated cyclic and aromatic hydrocarbons and nitrosopropane dimethylamine and diethylamine with known content, the identification of the chromatographic zone ON the contribution of microtomography, determining the number of CH-groups for nitrosoamine equal to the total toxicity hazard in the analyzed sample, the finding of the quantitative content amount ON largest holding arena in the sample and nitrosoamine most similar values hold the key pair, it is possible to more reliably determine the toxicity of 1-nitrosoamines in food products by comparing the content ON the unit weight of the food hygienic standard.

The proposed method of determining toxicity in food products is illustrated by the following examples.

Example 1. Determination of toxicity ON the offal. Taken from the average of the sample prepared by the weight to 1.0 kg, process x-rays in the x-ray apparatus ARINA-2M, sealed using vacuum packaging before sample preparation and stored in the refrigerator. Weighed on a technical scale (GOST 19491-74) lab sample product weight 975,4 g, after which it is ground in a meat grinder (GOST 15906-79) frozen and then homogenized using a mill. Mix dispergirovannoyj sample in paste form with a solid carrier, which is a glass powder with sizes of 5-10 mm in a volume ratio of 1:1, fill the mixture chromatographic column for liquid chromatography with a length of 50 cm and 5 cm in diameter, located vertically on the working plate vibrator. Installation for liquid chromatography consists of a chromatographic column, is provided in the lower part of the glass membrane type PORE 16 (GOST 9775-69), the upper part of which has a nozzle type Dean-stark that allows you to separate and remove water from the mixture with hydrocarbons, reverse water cooler (GOST 23932-79), two-neck nozzle and drip funnel (GOST 25336-82) to introduce the required quantity of eluent. To the bottom of the column attached to a two-neck round-bottom glass flask with electrooo the column with subsequent condensation.

For selection by liquid chromatography addition funnel fill the necessary amount of pentane, serves eluent in the upper part of the chromatographic column with such speed to ensure smooth flow of extract in a round bottom flask. When filling bulb extract 1/4 its volume concentrated by heating to the boiling point of pentane azeotrope with water, the pair arrive across a wide tube to the condenser and flow down in the form of phlegmy in the nozzle Dean-stark, where the water is separated as it is accumulated. Dehydrated hydrocarbon layer enters the chromatographic column for further separation nitrosoamines from fats, lipids and displacing nitrosoamines from the column. After the onset of the stationary mode chromatographic extraction anhydrous extract is directed through the lower valve in the dispenser to retrieve aerosol extract with a particle size of not more than 10 μm. Direct the flow of aerosol in a quartz capillary column gas chromatograph type Color-500 with a flame ionization detector with a length of 25 m and a diameter of 0.3-0.5 mm, prepared for capillary gas chromatography application from 5 to 10 mg hexadecane or immobilization vermicelli mode at 30°C. The mode of operation of the chromatograph: the temperature of the evaporator 125°C, detector 125°C, the flow rate of helium through the column 0.2 cm3/min, the flow rate of helium is discharged into the evaporator, 5 cm3/min, the flow rate of helium, podavaemogo in a flame ionization detector, 40 cm3/min, sensitivity scale electrometer 50·10-12A.

The spraying of the extract is performed by the flow of helium within the time required to stop the drift of the zero line signal detector, and then introducing a mixture of methane, cyclohexane, methyl-, ethylcyclohexane, benzene, toluene and ethylcyclopentane weighing up to 100 ng in the capillary column with the division of the flow. Chromatographic a mixture of cyclic and aromatic hydrocarbons in terms of analysis and define fixed (relatively nesorbiruyushchegosya methane) retention time of hydrocarbons and calculate withholding amounts by the formula:

where is the retention time, measured between the output rezorbiruetsa component (input samples) and maximum concentration of hydrocarbon, C;

Fo - volumetric flow of carrier gas through the column, cm3/s;

j is the correction for the compressibility of the carrier gas.

The retention time of benzene in the sample PAS of Costafilm3and cyclohexane 0,191 cm3, chromatographic zone is characterized by a logarithm relationship of benzene and cyclohexane, equal 0,8451, which is in the range of changes in these characteristics for aliphatic nitrosamines from 0,600 to 0,9105. Stop the flow of the eluate from the bottom of the flask by means of a crane, injected sequentially into the sprayer standard solutions nitrosodimethyl and diethylamine with a concentration of 500 µg/cm3in the amount of 1 mg of the analyte to determine the retention time of key pair hydrocarbons. On the dependence of the logarithm of the relations holding key-value pairs from the number of CH-bonds in nitrosopropane dimethylamine (6) and diethylamine (10) determine an approximation to the y-axis of the contribution of nitrosopropane, which amounted to standards of 1.27, and for the amount nitrosopropane aliphatic amines in the analyzed sample count the number of CH-groups, equal to 6.5. Therefore, the toxicity is determined by the content dimethylnitrosoamine having the option of holding a key pair that is closest to the analyzed sample. Quantitative determination of total content was carried out on time and amount of the retention of benzene in the sample and the NDMA. Based on the method supplements the trail is introduced dimethylnitrosoamine, mcg;

VN(x) - fixed the amount of the retention of benzene in the analyzed sample, cm3;

VN(EXT)- fixed the amount of the retention of benzene in addition, cm3.

Content amount in the sample by NDMA was 1093,5 μg, which corresponds 1,121 mg/kg of food product. Toxicity in the sample by-products was determined by comparing the content with the hygienic standard, equal to the amount AT 0.003 mg/kg according to SanPiN 2.3.2.1078-01, which exceeds the permissible level in 373,7±67.3 times. To assess the validity of this method was performed the analysis of similar samples by-products of the prototype.

Found dimethylnitrosoamine 54,0±40,5 mcg; diethylnitrosamine 24,7±11,0 mcg; nitrosopyrrolidine 343,0+257,0 mcg; nitrosodipropylamine, nitrosopiperidine, nitrosopiperidine not found. The calculation of the toxicity of chemicals with the same mechanism of biological action was performed according to the formula summing effect

where Ci- the content in 1 kg of food raw materials or foodstuffs mg/kg;

DNi- the maximum permissible level of receipt of the xenobiotic with food, mg/kg

Toxicodermia, equal to 0.003 mg/kg, which is considerably less compared to the proposed method.

Example 2. Determination of toxicity ON the offal of animals undergoing treatment for the treatment of helminthiasis piperazine-adipate. Taken from the average of the samples prepared in accordance with the technological regulations for this type of product, a portion of pork liver weight to 1.0 kg, process x-rays in the x-ray apparatus ARINA-2M, sealed using vacuum packaging before sample preparation and stored in the refrigerator. Weighed on a technical scale laboratory equipment product weight 986,3 g, after which it is ground in a meat grinder, frozen and then homogenized using a mill. Mix dispergirovannoyj sample in paste form with a solid carrier, representing a round glass beads or glass powder with a size of 5-10 mm, in a volume ratio of 1:1, fill the mixture chromatographic column for liquid chromatography with a length of 50 cm and 5 cm in diameter, located vertically on the working plate vibrator. Installation for liquid chromatography is similar to that described in example 1. For allocation ON a method geostrategically speakers with such speed, to ensure smooth flow of extract in a round bottom flask. When filling bulb extract 1/4 its volume concentrated by heating to the boiling point of the azeotrope, the pair arrive across a wide tube to the condenser and flow down in the form of phlegmy in the nozzle Dean-stark, where the water is separated as it is accumulated. Dehydrated hydrocarbon layer enters the chromatographic column for further separation from fats, lipids and displace ON from the column. After the onset of the stationary mode chromatographic extraction anhydrous extract is directed through the lower valve in an ultrasonic dispersing device to obtain aerosol extract with a particle size of not more than 10 μm. Direct the flow of aerosol in a quartz capillary column gas chromatograph type Color-500 with a flame ionization detector with a length of 25 m and a diameter of 0.3 mm, prepared for capillary gas chromatography application from 5 to 10 mg hexadecane. Column thermostated at isothermal conditions at a temperature of 30°C. the Mode of operation of the chromatograph: the temperature of the evaporator 125°C, detector 125°C, the flow rate of helium through the column 0.1 cm3/min, the flow rate of helium discharged in ispar the duration scale electrometer 50·10-12 A.

The flow of the extract is performed by passing helium within the time required to stop the drift of the zero line signal detector, and then introducing a mixture of methane, cyclohexane, methyl-, ethylcyclohexane, benzene, toluene and ethylbenzene weighing up to 100 ng in the capillary column with the division of the flow. Chromatographic a mixture of cyclic and aromatic hydrocarbons in terms of analysis, define fixed (relatively nesorbiruyushchegosya methane) retention time of hydrocarbons and calculate withholding amounts by the formula 1. The retention time of benzene in the sample PA was 1 min 36,82, toluene - 2 min 57,5 with, cyclohexane - 12,76 with, methylcyclohexane - 20,6 C.

The amount of the retention of benzene in the sample amounted to 0,1614 cm3, toluene - 0,2959 cm3, cyclohexane - 0,02137 cm3, methylcyclohexane - 0,03437 cm3. Chromatographic zone is characterized by a logarithm relationship toluene and methylcyclohexane equal 0,935, which is slightly higher than the value retention of key pairs for NDMA (the range of variation of these characteristics for aliphatic nitrosamines 0,583-0,928). Stop the flow of the eluate from the bottom of the flask by means of a crane, enter the village/SUP> in the amount of 1 mg of the analyte to determine the retention time of toluene and methylcyclohexane. On the dependence of the logarithm of the relations holding key-value pairs from the number of CH-bonds in nitrosopropane dimethylamine (6) and diethylamine (10) determine an approximation to the y-axis of the contribution of nitrosomyoglobin, which amounted to standards 1,445, and for the amount nitrosopropane amines in the analyzed sample count the number of CH-groups, equal to 5.9. Therefore, the value of hygienic regulations for determining the toxicity of the sample is chosen according to the NDMA, with 6 CH-groups in the alkyl substituents, equal to 0.003 mg/kg quantification was carried out according to the formula 2 based additives.

Content in the sample by NDMA was 111,1 μg, which corresponds to 0,1126 mg/kg pork liver. Toxicity in the sample offal of animals treated piperazine-adipate, was determined by comparing the content with the hygienic standard SanPiN 2.3.2.1078-01, which implies that the permissible level is exceeded 37.5±9.4 times. To assess the validity of this method was performed the analysis of similar samples by-products of the prototype.

Found dimethylnitrosoamine 5, is of Ilumina, pyrrolidine, piperidine, peligrosamente not found. The calculation of the toxicity of chemicals with the same mechanism of biological action was performed according to the formula 3.

The toxicity of the sample is 3.4±2,5 compared with the hygienic standard for the amount of nitrosopropane dimethylamine and diethylamine, which is almost an order of magnitude smaller compared with the proposed method.

Example 3. Determination of toxicity in smoked fish. Taken from the average of the samples prepared in accordance with the technological regulations for this type of product, a portion of the edible part of the fish cold or hot smoked, a solid portion of canned Fish smoked in oil by weight to 1.0 kg, process x-rays apparatus ARINA-2M, sealed using vacuum packaging before sample preparation and stored in the refrigerator. Weighed on a technical scale laboratory sample fish product weight 998,6 g, after which it is ground in a meat grinder, frozen and then homogenized using a mill. Mix dispergirovannoyj sample in the form of paste with a glass chip with a size of 5-10 mm in a volume ratio of 1:1, fill the mixture chromatographic column DL the ora. Installation for liquid chromatography consists of the same components and parts as described in example 1. The selection by liquid chromatography carried out similarly to the operation described in examples 1 and 2. After the onset of the stationary mode chromatographic extraction anhydrous extract is directed through the lower valve in the dispenser to retrieve aerosol extract with a particle size of not more than 10 μm. Direct the flow of aerosol in a quartz capillary column gas chromatograph prepared for capillary gas chromatography analogously to example 1. Column thermostated at isothermal conditions at a temperature of 30°C. the Mode of operation of the chromatograph Color-500 with the PID is the same as in example 2. Introducing a mixture of methane, cyclohexane, methyl-, ethylcyclohexane, benzene, toluene and ethylbenzene weighing up to 100 ng in the capillary column with the division of the flow and chromatographic a mixture of cyclic and aromatic hydrocarbons in terms of analysis and define fixed (relatively nesorbiruyushchegosya methane) retention time of hydrocarbons and calculate withholding amounts by the formula 1. The retention time of ethyl benzene was 43,95 with, ethylcyclohexane - 9,36 C.

The amount of retention of ethylbenzene is carried out by the logarithm of the relations of ethylbenzene and ethylcyclohexane, equal 0,672, which is close to the range of variation of these characteristics for aliphatic nitrosamines (0,5594-0,6324). Stop the flow of the eluate from the bottom of the flask by means of a crane, injected sequentially into the sprayer standard solutions nitrosodimethyl and diethylamine with a concentration of 500 µg/cm3in the amount of 1 mg of the analyte to determine the retention time of key pair hydrocarbons. On the dependence of the logarithm of the relationship of the retention of ethylbenzene to ethylcyclohexane on the number of CH-bonds in nitrosopropane dimethylamine (6) and diethylamine (10) determine an approximation to the y-axis of the contribution of nitrosomyoglobin, which amounted to standards 0,7425, and for the amount nitrosopropane aliphatic amines in the analyzed sample count the number of CH-groups, equal to 3.9. Therefore, the toxicity of the sample is determined by the content that has the option of holding that is closest to the analyzed sample. Quantitative determination was carried out on time and amount of the retention of ethylbenzene in the sample and the NDMA method supplements.

Content in the sample by NDMA was 16.3 μg, which corresponds to 0,01632 mg/kg Toxicity in the sample smoked fish products was determined by the level in 5,44±1.36 times. To assess the validity of this method was performed the analysis of similar samples by-products of the prototype.

Found dimethylnitrosoamine 2,90±2,05 mcg; diethylnitrosamine 2,27±1,70 mcg; nitrosopropane of dipropylamine, pyrrolidine, piperidine, overhydration and the research is not detected. The calculation of the toxicity of chemicals with the same mechanism of biological action was performed according to the formula summing effect 3.

The toxicity of the samples exceed the hygienic standard for the amount of nitrosopropane dimethylamine and diethylamine 1.72±1,29, which is considerably less compared to the proposed method.

As follows from the data shown in the table, the accuracy of determining the toxicity of polar nitrosopropane heterocyclic amines and amides in food products and food raw materials proposed method is much higher compared to the prototype. This will allow more accurate to evaluate their safety or to assess the risk of carcinogenic diseases.

The positive effect of the proposed method for determining toxicity in foods is to increase the reliability of the assessment of the toxicity due to the decrease in Noi chromatography nitrosopropane amines, and standards dimethyl - and diethylnitrosamine and, as a consequence, the reduction of error definitions.

The method of determining the toxicity of 1-nitrosoamines in food products, including sampling and sample preparation, chromatographic determination of hazardous substances and the assessment of their toxicity, characterized in that the sterile selected sample exposure to x-ray radiation, mix crushed and gomogenizirovannogo the sample with a glass solid carrier, miss eluent consisting of immiscible with moisture samples pentane distilled water azeotrope from the extract and subsequent circulation of eluent through the column length to the complete drying of the sample, serves atomized in an inert gas environment extract in a capillary chromatographic column, the inner surface of which is modified hydrophobic layer WITH16at a constant temperature in the range of 30-40°C, sequentially injected a mixture of saturated cyclic and aromatic hydrocarbons in the column caused the breakdown of nitrosoamines and additives dimethyl - and diethylnitrosamine with known mass, determine the magnitude of the retention of key pairs saturated cyclic and aromatic uglepodgotovitelnogo, identify the presence of chromatographic zones nitrosoamines on the contribution of microtomography, determine the number of CH-bonds in nitrosoamine samples of food by the dependence of the logarithm of the relations holding key pair for dimethyl - and diethylnitrosamine from them, are quantitative, the total content of nitrosoamines largest holding arena in aliphatic nitrosoamine with the logarithm of the retention of a key pair that is closest to the analyzed sample, determine toxicity by comparing the content of the sum of nitrosoamines per unit mass of product in hygienic standard.



 

Same patents:

The invention relates to food industry, namely the methods of determination of antimicrobial activity of plant oils

The invention relates to the field of sugar production, and is intended for quality control of raw materials and products for safety performance

The invention relates to the field of biochemistry, in particular the biochemistry of milk, and for evaluating the ability of biologically active substances of milk to inhibit the growth of microorganisms, in particular Escherichia coli

The invention relates to techniques for laboratory studies of processes of crystal formation in charcterised solutions when they are cooled and can be used in the sugar industry

The invention relates to techniques for laboratory studies of processes of crystal formation and crystallization from charcterised solutions when they are cooled and can be used in the sugar industry

The invention relates to the food industry and can be used for integral quality assessment of food products

The invention relates to devices for research in a wide range of changes in structural and mechanical characteristics of elastic-plastic-viscous materials, mainly food products (hard and soft cheeses, cottage cheese, curd-sweet mass, Margarines, butter, yogurt and other)

The invention relates to the food industry and relates to methods of assessing the quality of food and raw materials for their preparation

The invention relates to analytical chemistry of foods and can be used to identify and detect fraud coffee

The invention relates to the field of control of environmental pollution toxic fungi, particularly mushrooms pale toadstool Amanita phalloides

,'illogicality on individual index holding" target="_blank">

The invention relates to the field of chemical analysis and physical properties of substances, particularly to the analysis of non-biological materials by physical and chemical methods

The invention relates to chromatography, is intended to determine the total content of hydrocarbons in the air or in water and can be used to measure the concentration of hydrocarbons in the ambient air, in particular, in the working area sources of industrial emissions, as well as in natural and waste waters as part of environmental monitoring and other studies of environmental objects

The invention relates to gas chromatography and can be used to determine the constants distribution and other physico-chemical variables, for example, Henry's constants of volatile substances in the study of sorption equilibrium in the system non-volatile liquid - gas

The invention relates to analytical chemistry, and in particular to methods gas chromatographic determination of nitrous oxide, and can be used in chemical industry for analytical control of the production of mineral fertilizers

The invention relates to methods of research in occupational health, in particular to sanitary-hygienic laboratory conditions in terms of harmfulness and danger of chemical factors of the production environment, severity and intensity of the work process
The invention relates to research or analysis of materials, in particular to gas chromatography for the quantitative determination of high-boiling components of crude oil

The invention relates to gas chromatography and can be used to determine the quantitative and personal composition of volatile organochlorine compounds in crude oil, refined petroleum, chemical reagents oil-producing, oil-refining industry, and specifically can be used in the extraction, preparation, transportation and storage of oil

The invention relates to the field of analytical chemistry, and in particular to methods chromatographic determination of water content in gas mixtures

The invention relates to analytical control of anionic impurities in the water coolant with additives boric acid, which is realized in NPP and NPP with ammonia-boron-potassium water-chemical regime (water chemistry), by the method of two-column ion chromatography with pre-concentrated and direct conductometric detection and allows to solve problems of operational monitoring of mass concentrations of fluoride, chloride, nitrite-, nitrate-, phosphate and sulfate ions

FIELD: chemistry.

SUBSTANCE: relates to field of obtaining N-nitrosodialkylamines. Method of obtaining N-nitrosodialkylamines consists in interaction of water solutions of dialkylamines with carbon dioxide with molar ratio of dialkylamine to carbon dioxide (1÷2):1 with further processing of carnonates of dialkylamines with gas mixture of nitrogen with equimolecular mixture of nitrogen oxide and dioxide or gas mixture of nitrogen with nitrous anhydrite with molar ratio of dialkylamine to nitrogen oxides, in terms of nitrous anhydrite, not less than 1:1, reaction mass being kept at temperature 30-60°C, with support of pH of reaction mixtures 3-6.5 for 15-60 minutes.

EFFECT: invention makes it possible to reduce energy consumption, ensure ecological safety of technological production, with simultaneous increase of end product.

1 tbl, 12 ex

Up!