Method gas chromatographic determination cradlesong doses of halides and anhydrides of carboxylic acids in air of working zone

 

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 problem is solved in that the continuously during the shift take samples of the air at a speed of pulmonary ventilation through two parallel chromatographic columns at the beginning and end of which replaceable, porous filters, containing in suspension a specified number of sorbent - silanizing of chromo-sorbitol grain 0,125-0,200 mm coated in an amount of not less than 30% by weight of solid sorbent mixture of dealkylation heteroatomic polyhydric alcohols and heteroatomic amine, and the sorbent first column contains piperidine in an equivalent amount, in excess of the corresponding lethal dose of gelegenheid or anhydride of carboxylic acids, and in the other column was dispersed solid sorbent coated with a mixture of dialkylphenol and hexahydroazepin containing the latter in an equivalent amount, similar to the first column. To determine srednesemennyh dose at the beginning of the shift the cue amines, determine srednesemennyh dose based on the difference between the chromatographic retention parameters of benzene relative to hexane in allpresan heterocyclic amines from the mass of the analyte. The method allows to determine the influence of chemical factors on the body and working to improve the reliability assessment of risk when exposed to harmful substances in terms of harmfulness and danger factors of production environment severity and intensity of the labour process. 1 C. p. F.-ly, 3 tables.

The invention relates to sanitary-chemical research methods in health, in particular to a method of gas chromatographic determination cradlesong doses reactive and toxic halides and anhydrides of carboxylic acids in air of working zone (OCR) of industrial enterprises. It can be used for certification of workplaces according to the Manual P 2.2.755-99 "Hygienic assessment criteria and classification of working conditions in terms of harmfulness and danger factors of production environment, severity and intensity of the work process" to determine cradlesong doses of harmful substances).

Known gas chromatography JV anhydrides by absorption in an aqueous solution with subsequent entry into the chromatograph evaporator aliquot of sample solution, determination of the retention time of acetic acid (2 min 40 sec) when the temperature of the chromatography was carried out 150oWith in a chromatographic column made of stainless steel with a length of 2 meters and an inner diameter of 3 mm, filled with Polisorb 1 with 5% polyethylene glycol 20000, and the flow rate of the carrier gas equal to 30 cm3/min, with the quantitative determination of the concentration by the method of absolute calibration using a flame ionization detector. The average daily dose is determined by the graphic-analytical method according to Appendix 9 of the Manual. The lower detection limit of the concentration of acetic anhydride is 1.5 mg/m3(0.5 MAC) by passing 10 l SAS after 2 series-connected adsorption vessel, cooled with ice water, at the rate of 1 DM3/min. gas Chromatographic determination of organic acids complicated sorption phenomena in the evaporator column, high definition, close to the maximum operating temperature of the stationary phase, the Association of organic acids in the vapor phase, the dilution of the concentrate with chromatographic separation, so the technique cannot be used to accurately determine cradlesong doses of harmful substances Grafobal in SAS [MUK 4.1.169-96. The measurement of the concentration of harmful substances in the air of working zone: Met. Instructions. - Issue 29. - M.: publishing Information centre of the Ministry of health, 1998, page 303].

Also there is a method of gas chromatographic determination cradlesong doses propionitrile in the SAS, based on the hydrolysis of propionitrile to the free carboxylic acid in the concentration of air samples in aqueous solution with subsequent entry into the chromatograph evaporator aliquot of sample solution, the determination of the retention time propionic acid (2 min 35 sec) when the temperature of the chromatography was carried out 150oWith in a chromatographic column made of glass or stainless steel with a length of 0.5 m and an inner diameter of 3 mm, filled with Polisorb 1 (fraction of 0.25-0.5 mm) and the flow rate of the carrier gas, equal to 35 cm3/min, with quantification by the method of absolute calibration using a flame ionization detector. The average daily dose is determined by the graphic-analytical method according to Appendix 9 of the Manual. The lower detection limit concentration propionitrile is 0.1 mg/m3(0,05 MAC) by passing 15 DM3SAS through the adsorption device with a porous plate, a cooled mixture of acid and other carboxylic acids with molar mass, close to the molar mass of propionic acid, so the measurement error exceeds 20% due to insufficient separation chromatographically connections and overlapping chromatographic peaks [MU 6001-91, page 199]. To improve the separation of the extraction is carried out in diethyl ether organic acids from aqueous absorber with the addition of vicariates. However, this method of concentration time-consuming and laborious. So srednespinka dose cannot be determined with sufficient accuracy as the product srednesemennyh concentration of total time working operations during the shift.

The closest in technical essence and the achieved result is a method of qualitative and quantitative analysis of low volatile polar organic compounds in air, based on the fact that during the shift select grab samples of air in the volume and number recommended by Annex 9 Guidance, by processing the volatile organic solvent to extract the amount of the polar low volatile organic compounds, are prepared sample on a solid sorbent, which is a chromatographic column of the first chromatograph equipped with a thermal conductivity detector, vysushennogo solvent, enter the model mixture of hexane and benzene to measure the retention time of benzene relative to hexane and air at a temperature of thermostat 30oTo determine the amount of the retention of benzene with respect to the hexane and air at a given speed of carrier gas from 5 to 40 cm3/min, and then subjected to a test of chromatically, which raise the temperature in thermostat first chromatograph to the boiling point of the low-boiling component and identify polar low volatile organic compound in terms of the retention volumes of benzene relative to hexane and air, and the concentration of the polar low volatile organic compounds is determined by the dependence of the volume of the retention of benzene relative to hexane from its mass. The average daily dose can be defined by a geographical method according to Appendix 9 of the Guide by multiplying srednesemennyh concentration of total time working operations during the shift [RF Patent 2165618 from 20.04.01].

However, the method is not suitable for determining srednesemennyh doses of volatile compounds, which include the halides and anhydrides of carboxylic acids because of their breakthrough in the process of sampling and holding their hydrolysis by visiprise the her the prototype leads to increased error in determining the dose of harmful substances, associated with the adsorption of benzene on the boundary surfaces: gas - polar stationary phase (carboxylic acid), a polar stationary phase is a solid carrier.

The objective of the invention is to improve the accuracy of determining srednesemennyh dose of halides and anhydrides of carboxylic acids in the working zone air.

The problem is solved in that select srednesemennyh samples of the air of the working zone in a certified workplace during the time of operations of the technological process. To do this, pass the sample through OCR two parallel chromatographic column with a speed corresponding pulmonary ventilation during exercise on certified workplace, which are placed in suspension silanizing the chromo-sorbitol grain 0,125-0,200 mm coated with not less than 30% by weight of solid sorbent mixture of dealkylation heteroatomic polyhydric alcohols (dialkylphenol) and a heterocyclic amine, and the sorbent first column contains piperidine in an equivalent amount, in excess of the corresponding lethal dose of gelegenheid or anhydride of carboxylic acids. In another column is dispersed solid sorbent coated with a mixture of dialkylphenol and the division srednesemennyh dose at the beginning of the shift or work operation serves the carrier gas into the chromatographic column, containing on the surface of the stationary liquid phase sorbent various heterocyclic amines, with constant speed up to 5 cm3/min, injected aliquot sample benzene-hexane at a temperature corresponding to the parameters of the microclimate of the workplace in each of the columns. Then measure the chromatographic retention parameters of benzene relative to hexane using a chromatographic detector. At the end of the shift or work operation after removal of volatile impurities similarly carry out the measurement of chromatographic retention parameters of the model mixture in both columns, then determine the difference between the chromatographic retention parameters of benzene relative to hexane in a 1-arylpiperazine (first column) and 1-aciphexhydrocodone (second column) per shift or working operation. Srednesemennyh dose gelegenheid anhydride and carboxylic acid calculated from the equations of dependence of the volume of the retention of benzene relative to hexane in both columns. Identification of gelegenheid and anhydride is carried out on the logarithm of the ratio of the retention of benzene relative to hexane in a 1-arylpiperazine to the volume of the retention of benzene relative to hexane in a 1-aciphexhydrocodone.

When the cutting which replaceable, porous filters, preventing the loss of solid sorbent. In the first column make a specified amount of solid sorbent in the form of silanizing of chromo-sorbitol grain 0,125-0,200 mm coated in the amount of 30 wt.% the mixture dialkylamide ether of diethylene glycol or its polymers with heterocyclic amine, which is used as piperidine in an equivalent amount exceeding the lethal dose of the analyte. The second column make the same amount of solid sorbent coated with a stationary phase, only as a heterocyclic amine used hexahydroazepin in the same equivalent amount. To determine the magnitude srednesemennyh dose gelegenheid and anhydride of carboxylic acids before the change is measured chromatographic retention parameters of benzene relative to hexane by absorbing sorbent in each column. This serves helium or nitrogen in the chromatographic column at a constant speed up to 5 cm3/min at a temperature of 20-30oWith corresponding parameters of the microclimate in the workplace are introduced with a syringe or faucet spout depending on the sensitivity of the detector required amount of the mixture hexane-benzene in equal sootnosheniya and hexahydroazepin at the beginning of the work shift, measuring the distance between the peak of hexane and the maximum concentration of benzene.

Calculate withholding amounts of benzene relative to hexane by the formula1 - the distance between the peak of hexane and maximum concentrations of benzene, mm; F0- volumetric flow rate of the carrier gas, cm3/s; v - speed of movement of the ribbon diagram, mm/s; j is the correction for compressibility.

Then on certified workplace select two parallel samples SAS using the aspirator, skipping during the shift speed corresponding to the pulmonary ventilation during exercise on certified workplace, through two chromatographic columns with sorbent is in a suspended state, the surface of which are a mixture of dealkylation heteroatomic polyhydric alcohols (dialkylphenol) and heterocyclic amines, different size rings on one methylene group and converting the reactive halides and anhydrides of carboxylic acids in sustainable low volatile compounds. In the end, stop sampling and measure the final chromatographic retention parameters of benzene relative to hexane by absorbing sorbent in each column. To do this, the PCC is irovannyh volatile impurities, which can be analyzed by other methods, and carry out the measurement of chromatographic retention parameters of the model mixture in both columns. Then determine the difference between the chromatographic retention parameters of benzene relative to hexane in allpresan of piperidine and hexahydroazepin per shift. Parallel rednisone dose calculated by the following equations:VAP(b/g)=K1VWCT(b/g)x1(2)VAA(b/g)=K2Vhmmm(b/g)x2(3) where x is the content (weight) of gelegenheid or anhydride in the sample, mg; VgAP(b/g)- the specific volume of the retention of benzene relative to hexane in a 1-arylpiperazine, cm3/mg;
VgAA(b/g)- the specific volume of the retention of benzene relative to hexane in a 1-aciphexhydrocodone, cm3/mg;
To1is the stoichiometric coefficient of 1-arylpiperazine towards gelegenheid or anhydride of carboxylic acids;
To2is the stoichiometric coefficient of 1-aciphexhydrocodone towards gelegenheid or anhydride of carboxylic acids.

The values of the stoichiometric coefficients of the 1-arylpiperazine in table 1.

Values of specific withholding volumes of benzene relative to hexane in a 1-arylpiperazine and 1-aciphexhydrocodone in the temperature range of life processes pre-defined application of these substances on selected sorbents by the method of inverse gas chromatography and is presented in table 2.

A comparison of the logarithm of the relations of the retention volumes of benzene relative to hexane in a 1-arylpiperazine and 1-aciphexhydrocodone, identifies in a sample the air of working zone gelegenheid or anhydride of carboxylic acids. If these relationships in a sample SAS does not coincide with the previously determined for pure substances, the determination of the average daily dose is conducted by the method of additions. For this purpose selected to average the sample on the sorbent, containing piperidine add successively two attachment 1-arylpiperazine weighing from 1 to 10 mg and calculate the volume of the retention of benzene relative to hexane similarly to the above measurement. On the graph of dependence of the volume of the retention of benzene relative to hexane in a 1-arylpiperazine by weight of the weighed to determine the weight of the derivative, the corresponding average daily dose of gelegenheid or anhydride of carboxylic acids and convert its AA is entrusted the essential features of the claimed method are the following.

- Continuous during the shift sampling passing SAS through two chromatographic column with a speed corresponding pulmonary ventilation during exercise on certified workplace allows you to more accurately assess the influence of chemical factors on the health of workers, as a single sample within a smaller period of time leads to a distortion of results definitions average daily samples due to intermittent or with different arrival rate BB for change in the various operations of the process.

- The use of suspended solid sorbent coated with not less than 30 wt.% the mixture dialkylamino esters heteroatomic polyhydric alcohols or polymers with heterocyclic amines in an equivalent amount, in excess of the corresponding lethal dose of gelegenheid and anhydride of carboxylic acids, allows complete transfer of labile toxic and non-volatile moreaccessible derivative whose mass can be determined with high accuracy by the method of inverse gas chromatography. The use of this adsorbent in suspension allows you to effectively catch halogenosilanes OCR.

- The model using a mixture of benzene-hexane to measure the chromatographic retention parameters in allpresan heterocyclic amines by the method of inverse gas chromatography increases the accuracy of determining the average daily dose of the analyzed substances in comparison with polar model substances, in particular dialkylamino, pyridine, nitromethane, due to the absence of their adsorption on the surfaces of a section of gas - liquid stationary phase, the liquid stationary phase is a solid sorbent.

- Use as heterocyclic amines piperidine and hexahydroazepin compared with aziridines, azetidines and pyrrolidino, allows you to more accurately measure the chromatographic retention parameters of the model mix, as they have significant volatility even in mixtures with ethers heteroatomic polyols.

- Use as heterocyclic amines piperidine and hexahydroazepin compared to compounds with the size of the cycle more than 8 atoms, allows you to more accurately measure the chromatographic parameters of benzene relative to hexane, since the parameters of the retention of hydrocarbons in connection with the large size of the loop is not additive, that abuseable the nye set of stated characteristics are provided by the solution of the invention - improving the accuracy of determining srednesemennyh dose of halides and anhydrides of carboxylic acids in the working zone air.

The proposed method gas chromatographic determination cradlesong doses of halides and anhydrides of carboxylic acids in the SAS industrial enterprises is illustrated by the following examples.

Example 1. To determine srednesemennyh concentration of acetic anhydride in OCR shop acetylation of cellulose plant Plastpolymer take samples analyzed air at a speed of 25 DM3/min according to the recommendations of Annex 9 Guidelines R 2.2.755-99. On certified workplace select two parallel samples using a four-channel aspirator AR-4-220V-40 by passing through the chromatographic column with sorbent, one of which is suspended mixture dibutylamino ether of diethylene glycol and piperidine (mass 0,8435 g) in an amount of 30 wt.% from mass silanizing of chromo-sorbitol grain 0,125-0,200 mm and the other with a mixture of ether and hexahydroazepin (mass 0,9823 g), for the quantitative conversion of acetic anhydride to 1-acetylpiperidine and 1-acetylgalactosamine. In the end, stop sampling and measure chromatograhic miss inert gas at a rate of up to 5 cm3/min at the previously selected temperature to remove adsorbed volatiles, after analysis by the method of direct chromatography revealed the presence of benzene 5,34of 1.30 mg/m3, which is used as a solvent in the acetylation. Determine the difference between the chromatographic retention parameters of benzene relative to hexane in a 1-acetylpiperidine and 1-acetylgalactosamine per shift, which was 431,1 cm3and 409,5 cm3respectively. Srednesemennyh dose calculated using equations 2 and 3, and the specific volume of the retention of benzene relative to hexane in a 1-acetylpiperidine was 1,2341 cm3/mg, and the specific volume of the retention of benzene relative to hexane in a 1-acetylgalactosamine 1,0559 cm3/mg, and their ratio is equal to 1,169. At the same time, the stoichiometric ratio of 1-acetylpiperidine towards acetic anhydride equal 0,8038, and a stoichiometric ratio of 1-acetylgalactosamine towards acetic anhydride 0,7240.

Values of specific withholding volumes of benzene relative to hexane in a 1-acetylpiperidine (MRTU 6-09-360-63) and 1-acetylgalactosamine in the range of 20-30oSince it was determined by the method obermaneken 1-acetylpiperidine and 1-acetylgalactosamine in the sample and the data of table 3 establish a presence in the sample SAS acetic anhydride, since this ratio in the sample SAS taking into account the molar masses as 1,1688, and according to table 3 1,1687, they are almost the same. The calculation of the parallel cradlesong doses of acetic anhydride was carried out according to the above equations, and they are equal: x1=281,9 mg; x2=280,7 mg (xcf=281,8 mg). The maximum deviation from the average is 0.04%.

The obtained values of mean daily doses help to assess the risk of morbidity operating under the influence of harmful substances.

Example 2. To determine srednesemennyh concentration of propionic acid chloride of acid (propionitrile) in SAS in the production of morphine at the stage of acylation lithium alcoholate 1,2,5-trimethyl-4-phenylpiperidine-4 take samples analyzed air at a speed of 25 DM3/min according to the recommendations of Annex 9 Guidelines R 2.2.755-99. On certified workplace select two parallel samples using a four-channel aspirator AR-4-220V-40 by passing through the chromatographic column with sorbent, one of which is suspended a mixture of diethyl ether of triethylene glycol and piperidine (mass 0,9561 g) in an amount of 30 wt.% from mass silanizing of chromo-sorbitol grain 0,125-0,200 of Idrija propionic acid 1-Propionaldehyde and 1-propionylacetate, in the beginning was measured initial chromatographic retention parameters of benzene relative to hexane. In the end, stop sampling and measure chromatographic retention parameters of benzene relative to hexane by absorbing sorbent in each column. To do this, pass an inert gas at a rate of up to 5 cm3/min at the previously selected temperature to remove adsorbed volatiles, after analysis by the method of direct chromatography revealed the presence of methylamine 0,0050.001 mg/m3and benzene 0,260.05 mg/m3used in the synthesis as solvent.

Determine the difference between the chromatographic retention parameters of benzene relative to hexane in a 1-propenylidene and 1-propionylcarnitine per shift, which was 147,1 cm3and 132,3 cm3respectively. Srednesemennyh dose calculated using equations 2 and 3, and the specific volume of the retention of benzene relative to hexane in a 1-propenylidene was 1,1392 cm3/mg, and the specific volume of the retention of benzene relative to hexane in a 1-propionylcarnitine 0,9316 cm3/mg, and their ratio is equal to 1,223. Then W is geometricheskii factor 1-propionylcarnitine towards propionitrile 0,5969.

Values of specific withholding volumes of benzene relative to hexane in a 1-propenylidene and 1-propionylcarnitine in the range of 20-30oSince it was determined by the method of inverse gas chromatography.

By comparing the logarithms of the relationship of the retention volumes of benzene relative to hexane in a 1-propenylidene and 1-propionylcarnitine in the sample and table 2 define the presence in the sample SAS propionitrile, since this ratio in the sample SAS taking into account the molar mass is equal 1,223 and practically does not differ from the table values. Therefore, the calculation of the parallel cradlesong doses propionitrile carried out analogously to example 1: x1=84,64 mg; x2= 85,17 mg (xcf=84,90 mg). The maximum deviation from the average value of 0.32%.

The obtained values of mean daily doses help to assess the risk of morbidity operating under the influence of harmful substances.

Example 3. To determine srednesemennyh concentration of acetic anhydride in the SAS during the production atseklidina on stage acetylation of 3-oxyhemoglobin take samples analyzed air analogously to example 1 through a chromatographic column with sorbent is in a suspended state, one of which is located 30 wt.% from mass silanizing of chromo-sorbitol grain 0,125-0,200 mm, and the other with a mixture of ether and hexahydroazepin (mass 1,4502 g) for the quantitative conversion of acetic anhydride to 1-acetylpiperidine and 1-acetylgalactosamine. Other operations determine the start and end of the chromatographic parameters of the model mixture of benzene-hexane to columns with various heterocyclic amines carried out accordingly to the algorithm of the method described in example 1.

For comparative characteristics at the same time at the same workplace samples were taken OCR similar to the algorithm of the method of qualitative and quantitative analysis of low volatile polar organic compounds in air, followed by the calculation cradlesong doses of harmful substances graphic-analytical method and application 9 a according to the method of the prototype. Process the surveyed area was divided into 4 stages in one shift. At the first stage, we selected 3 samples on the second and third stage 2 samples and 1 sample in the fourth stage, which was analyzed in the manner specified above. The results of measurements of concentrations in ascending order were compared with the duration of sampling. Time sampling all samples are summed and taken as 100%. After this was determined by the accumulated frequency is astou grid caused the value of the concentration on the x-axis and the corresponding cumulative frequencies (in %) on the ordinate axis. Through the plotted points held straight and determined the median value at the intersection of the direct integral with 50% probability value. Determined the value of x84and expected geometric standard deviation characterizing the limits of fluctuations of concentration. According to the formulae given in Annex 9 Guidance, expected srednesemennyh concentration. Srednespinka dose was calculated as the product of srednesemennyh concentration during the change, as the proposed method. Table 3 presents the results of the comparative characteristics of the method of gas chromatographic determination cradlesong doses of halides and anhydrides of carboxylic acids in the air of working zones of industrial enterprises and method of qualitative and quantitative analysis of low volatile polar organic compounds in the air.

As follows from the data of example 3, the proposed method allows for more accurate compared to the prototype to determine the average daily dose of halides and anhydrides of carboxylic acids in the OCR.

Table 3 presents the results of the comparative characteristics of the application of various amines in mixtures with dialkylamino in the way gas chromatographic determination the acetyl chloride was created using gas installation "Microgap" 2.966.057, use for the preparation of gas mixtures in the calibration of the chromatograph under the conditions of operation described in the article "Barbituric acid, analytical reagent for the determination of freon circulating way to create concentrations" [VINITI. - Dept. scient. . - 2, 1989, S. 188] . As dosed substances used acetyl chloride (GOST 5829-51).

As can be seen from table 3, the proposed method can significantly more accurately than using as heterocyclic amines of aziridine and azetidine, azetidine and pyrrolidine to determine the average daily dose of acetyl chloride due to significant volatility and lower basicity of heterocyclic amines small cycles. At the same time, the use of aliphatic amines with higher basicity (dimethyl - and diethylamino) does not lead to a significant improvement in the accuracy of the proposed method. Lower accuracy was achieved when used in mixtures with dialkylamino system of heterocyclic amines with the size of the cycle more than 8 atoms, in particular azacycloheptane and azacyclonol.

Thus, in the continuous sampling of air at a rate of pulmonary ventilation during the working is simple filters with a sorbent in a suspended state, which is used silanizing the chromo-sorbitol grain 0,125-0,200 mm printed on its surface in an amount of not less than 30 wt.% a mixture of dealkylation heteroatomic polyhydric alcohols or polymers with piperidine in the first column and hexahydroazepin in the second column in an equivalent amount exceeding the lethal dose of the analyzed substances, sample preparation for chromatographic analysis by removing volatile compounds, measurements before and after sampling chromatographic retention parameters of benzene relative to hexane by absorbing sorbent in each column, the identification of harmful substances in the logarithm of the relationship of the retention volumes of benzene relative to hexane in acyl derivatives of piperidine and hexahydroazepin, distinguished by the size of the cycle 1 methylene group, it is possible to more accurately determine srednesemennyh dose based on the difference between the chromatographic retention parameters of benzene relative to hexane in allpresan heterocyclic amines from the mass of the analyte.

The positive effect of the proposed method gas chromatographic determination cradlesong doses of halides and anhydrides of carboxylic cilia chemical factors on the body working and improving the reliability of the assessment of risk when exposed to harmful substances in terms of harmfulness and danger factors of production environment severity and intensity of the labour process.


Claims

1. Method gas chromatographic determination cradlesong doses of halides and anhydrides of carboxylic acids in the air of working zone, which includes the sampling of air during the shift, sample preparation for chromatographic analysis, the determination of the number of analyzed substances, characterized in that the continuously during the shift take samples of the air at a speed corresponding to the pulmonary ventilation during exercise on certified workplace, through two parallel chromatographic columns, which are placed in suspension for a specified number of sorbent, measured before and after sampling chromatographic retention parameters of benzene relative to hexane by absorbing sorbent in each column, define srednesemennyh dose based on the difference between the chromatographic retention parameters of benzene relative to hexane in allpresan heterocyclic amines from the mass of the analyte.

2. The method according to p. 1, characterized in that the sorbent is used silanizing the chromo-sorbitol grain 0,125-0,200 mm, the surface of which is applied in an amount of not less than 30 wt.% a mixture of dialkylamino the hetaera column in an equivalent amount, exceeding the lethal dose of the analyte.

 

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SUBSTANCE: method involves plotting two chromatograms one of which is based on radioactivity (No 1) and the other one on ultraviolet absorption (No 2) or on radioactivity (No 1) and on fluorescence (No 2) and chromatogram specific relative to ultraviolet absorption (No 3) or relative to fluorescence (No 3). Material quality is estimated to be the more high the more close studied labeled compound peak shape is to trapezoid shape on the third chromatogram.

EFFECT: high accuracy of the method.

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