[Determination of toxic element concentrations in flour and cereal products by mass spectrometry with inductively coupled plasma].

Systemic control and monitoring in the sphere of providing sanitary epidemiological welfare of population require routine procedures for determining toxic elements in variable foodstuffs. Their development is a pressing issue. Our research goal was to develop a procedure for determining concentrations of arsenic, cadmium, lead, mercury, aluminum and strontium in flour and cereal products by mass spectrometry with inductively coupled plasma. Material and methods. The most relevant calibration parameters for an Agilent 7900 mass spectrometer with octopole collision/ reaction cell and conditions for sample preparation by microwave digestion have been established; calibration characteristics and a range of determined concentrations have been identified. The limits of detections (LOD) and limits of quantification (LOQ) for 6 analyzed elements have been calculated. Results. Our procedure for determining mass concentrations of arsenic, cadmium, lead, mercury, aluminum and strontium in flour and cereal products by mass spectrometry with inductively coupled plasma has yielded the following results: when analyzing a sample weighing 0.5 g, we determine cadmium concentration within a range from 0.0008 to 70.0 mg/kg with inaccuracy from 14 to 25%; arsenic concentration within a range from 0.002 to 70 mg/kg with inaccuracy varying from 11 to 26%; mercury concentration from 0.003 to 7.0 mg/kg with inaccuracy from 15 to 25%; lead concentration from 0.01 to 70.0 mg/kg with inaccuracy from 12 to 26%; aluminum concentration from 0.2 to 70.0 mg/kg with inaccuracy from 13 to 20%; strontium concentration from 0.02 to 70 mg/kg with inaccuracy from 12 to 20%. The procedure was tested on samples of rice groats with the focus on the most popular brands. Thus, arsenic was detected in a concentration equal to 0.163 mg/kg in round-grain rice and 0.098 mg/kg in parboiled rice, which does not exceed the permissible level fixed for the element at 0.2 mg/kg. In all the analyzed samples, content of cadmium, lead and mercury did not exceed maximum permissible levels established by the Technical regulation of the Customs Union TR CU 021/2011 for flour and cereal products. These levels are 0.1 mg/kg for cadmium, 0.5 mg/kg for lead and 0.03 mg/kg for mercury. Conclusion. The developed procedure for determining toxic elements in flour, cereals and bakery products by using mass spectrometry with inductively coupled plasma gives an opportunity to determine such elements in quantities lower than permissible levels fixed for them in technical regulations and sanitary rules. The procedure expands the existing methodical instruments for control of food quality in the Russian Federation.

[Identification and chromatemass- spectrometry quantification of toxic chemicals (N-nitrosamines, phthalates) in baby foods].

Currently, assessing exposure to toxic chemicals detected in foodstuffs is a vital issue, especially regarding foods for babies and toddlers. The research goal was to identify and quantify toxic chemicals (N-nitrosamines, phthalates) in baby foods. Material and methods. Our research objects were 21 samples of canned meat and vegetable purees; 30 samples of juices. All samples were bought in retail outlets. We applied solid phase extraction to prepare the samples for the chromatographic analysis. Chemicals were identified in samples by a hybrid technique, gas chromatography and quadrupole mass spectrometry (GC-MS). The components were classified by comparing the mass spectra we obtained with spectra of specific chemicals and data from the following libraries: NIST 08.L, WILEY275.L and PMW_TOX2.L, AMDIS, USEPA (US Environmental Protection Agency) database with identification numbers of environmental pollutants; libraries containing mass spectra of narcotics, drugs, toxic pollutants and pesticides. Quantitative determination of phthalates in juice products by HPLC/MS was performed. Results. We identified three toxic chemicals in the analyzed canned meat and vegetable purees for babies. They belonged to the 1-3 hazard category and to different classes of organic compounds. Specifically, we identified nitrogen-containing chemicals (N-nitrosamines within a range of concentrations being 0.00077-0.0015 mg/kg with a 73% probability that a mass spectrum would match one taken from a library) in 52.9% of samples. These chemicals are not allowed in canned meat purees for babies by the Technical Regulations TR CU 021/2011 (<0.001 mg/kg). Next, we identified dibutyl phthalate and diethyl phthalate in 30.0% of samples; contents of these organic compounds in canned meat purees for babies are not stipulated by the TR CU 021/2011. We also identified an aromatic compound, namely furfural in 21.7% of samples, and a food additive, 2-butenoic acid (E570) in 5.3% of samples; their contents are regulated by the Technical Regulations TR CU 029/2012. Three toxic chemicals were identified in the analyzed juice samples. First, N-nitrosodiethylamine and N-nitrosodimethylamine were identified in 56.7% of samples (with a 73% probability that a mass spectrum would match one taken from a library, over a concentration range of 0.00045- 0.00077 mg/kg). Second, we identified phthalates (dibutyl phthalate, diethyl phthalate, and diisobutyl phthalate) in 30% of samples (in the concentration range from 0.4 to 59.26 mg/l). The contents of these compounds in juices for babies are not regulated by the TR CU 021/2011. We also detected furfural in 56.7% of samples (with a value of the coefficient of coincidence with library data of 90%), the use of which is regulated in TR CU 029/2012. Conclusion. We have developed and experimentally substantiated an algorithm of an analytical study with its focus on preparing food samples for further identification of chemicals in them. The algorithm involves using a complex technique that combines distillation, solid phase extraction, gas chromatography and mass spectrometry. This technique provides an opportunity to identify a component structure of complex chemical mixtures in food samples with high probability and reliability. It also provides solid evidence that organic compounds occur in food samples based on comparing analytical mass spectra with those taken from mass spectral libraries.

[Phthalate analysis in foods for young children using LC-MS method].

Phthalates are esters of phthalic acid, which are persistent organic pollutants of the environment. Phthalates are widely used as plasticizing additives in the production of polymer products for industrial, domestic, food and medical purposes. The ubiquitous presence of phthalates is confirmed by the results of studies of environmental objects, drinking water, and foodstuffs. In connection with the adverse effects of phthalates on health, it is important to control their content in foodstuffs, including baby food, as one of the main sources of phthalates. The aim of the research was to determine the phthalate content in baby food products (from 0 to 3 years) and to assess it from the hygienic point of view. Material and methods. The results of the analysis of phthalates (C1-C8) in the dehydrated baby food products (milk porridge, dairy-free porridge, adapted milk formula, milk drink) by high-performance liquid chromatography/mass spectrometry (LC/MS-MS) are presented. Results. The presence of 7 phthalates out of 9 analyzed in the concentration range from 0.003 to 0.199 mg/kg was established. The priority contaminants were diethyl phthalate, determined a t concentrations ranging from 0.046 to 0.199 mg/kg in 100% of samples, and bis(2-ethylhexyl)phthalate, present in 75% of samples in concentrations ranging from 0.011 to 0.115 mg/kg. Dipropyl phthalate (0.004-0.055 mg/kg) and dihexyl phthalate (0.006-0.062 mg/kg) were found in low concentrations in all samples. Dibutyl phthalate was found at the lower limit of determination - 0.005-0.007 mg/kg. The maximum phthalate content was established in milk and dairy-free porridges. Health risk assessment formed by phthalate intake from milk and dairy-free porridges, adapted milk formula and milk drink, when comparing the daily intake of individual phthalates with recommended reference doses for chronic per os intake, showed that no exceeding of permissible risk levels was found. Conclusion. The maximum phthalate contamination is set for milk porridge and dairyfree porridge. The priority pollutants in the studied samples are diethyl phthalate and bis(2-ethylhexyl)phthalate. The danger coefficient calculated for each baby food product, as well as hazard indices for the consumption of all products together, do not exceed the permissible values, which indicates an acceptable risk to public health.

[Comparative assessment of N-nitrosamines' contamination of baby's canned meat with vegetables and cereals by various methods in Russia and Vietnam].

The quality and safety of food, intended for baby in particular, is one of the global issues of our time. The group of carcinogenic N-nitrosamines is of especially dangerous. It is worth mentioning that currently there are no standards for their content in Vietnam. Therefore, to ensure the chemical safety of infant food, it is necessary to improve the control system, including the development of modern technical and methodological base. The aim of the research is the comparative assessment of contamination with highly toxic, N-nitrosoamines of baby canned meat and vegetable products by the gas chromatography-mass spectrometry (GC/MS) using an automatic solid-phase extraction system and gas chromatography-tandem mass spectrometry (GC-MS/MS). Material and methods. The objects of research were homogenized canned meat-vegetable products for baby nutrition - 21 samples taken from the distribution network of the Republic of Vietnam: vegetables and rice with chicken (sample No. 1); sweet corn with mashed potatoes and turkey (sample No. 2); potatoes with veal (sample No. 3); each species has 7 samples. Each food sample was analyzed thrice by two methods. At the Federal Center of Perm, the screening studies of canned foods were performed using GC/ MS with application of the automatic solid-phase extraction system (SPE) after distillation using alkaline catalysis at the sample preparation stage. At the National Institute of Food Control of Republic of Viеtnam, canned samples were studied using GC-MS/MS. The extraction method was developed on the base of QuEChERS-approach. Results and discussion. During the research, the following chemical contaminants were found in the canned samples: N-nitrosodimethylamine, N-nitrosodiethylamine, N-methylethyl nitrosoamine, N-dipropylnitrosoamine, N-dibutyl nitrosoamine, N-piperidinitrozoamine, N-pyrrolidinin nitrosoamine, N-morpholinithrosamine and N-diphenyl nitrosoamine. It was demonstrated that the results of quantitative determination of the content of N-nitrosoamines in canned meat of Vietnam producers obtained in different laboratories are comparable and have good validation characteristics for the determination of N-nitrosoamines in baby food. Thus, N-nitrosodimethylamine was detected by both methods in all analyzed samples in the concentration range from 0.00045 to 0.00077 mg/kg. Values exceeding the maximum permissible level of N-nitrosoamines (N-nitrosodimethylamine and N-nitrosodiethylamine) in canned meat and vegetable samples (0.001 mg/kg according to Technical Regulations of the Customs Union TR TC 021/ 2011 "On Food Safety") were not found. The application of low-resolution gas chromatography-mass spectrometry and the use of an automatic SPE system made it possible to achieve high comparability of the results in chemical analysis of N-nitrosoamines in canned products obtained in the laboratory of the Center and the National Institute for Food Control of Vietnam. Conclusion. The executed studies indicate the need for further monitoring of the content of chemicals in baby products in order to justify methodological approaches to the analysis of the risk of the simultaneous effect of chemical contaminants on the health of children. In this regard, it seems extremely important and relevant issue of hygienic regulation of the content of the studied compounds in products for baby food.

[Development and application of gas chromatographymass spectrometry method for quantitive determination of volatile N-nitrosamines in smoked meat products].

The article presents the results of experimental studies on the development of highly sensitive and selective chromatography-mass spectrometry technique for the determination of 9 N-nitrosamines in food samples (sausage products) using distillation and an automatic solid-phase extraction system on Coconut cartridges for sample preparation. In the elaborated conditions of sample preparation (distillation and solid-phase extraction) and chromatography-mass spectrometric analysis, we achieved a high recovery and efficiency of the separation of nine N-nitrosamines. The quantitation limit was at level of 0.0002 mg/kg with maximum error not exceeding 19%. The complex use of the distillation of N-nitrosamines with the addition of potassium hydroxide in combination with the optimal elution scheme for solid-phase extraction and concentrating the distillate into a Coconut carbon cartridge of 6 ml ensures the recovery of N-nitrosamines from the food product sample (sausage products) up to 93.2-100%. The process of approbation of the chromatography-mass spectrometric method in the samples of food products (sausage products) of various manufacturers revealed the content of N-nitrosamines in the concentration range 0.00029±0.000055÷0.350±0.05 mg/kg. The conducted studies of the content of the sum of highly toxic N-nitrosamines (N-nitrosodimethylamine, N-nitrosodiethylamine) made it possible to disclose that in sample No. 5 the maximum allowable concentration was exceeded by 47 times, in samples No. 2 and 16, to 57.5 and 22.9 times and in sample No. 4 to 88 times, respectively.

Diagnostics of Early Changes in the Immune System Due to Low Concentration of N-Nitrosamines in the Blood.

The concentration of N-nitrosamines (N-nitrosodimethylamine and N-nitrosodiethylamine) was measured in blood samples from children after consumption of drinking water with high content of nitrates (main group) or water meeting health standards (reference group). N-nitrosodimethylamine level in the blood from children of the main group differed from that in the reference group by 2.6 times (0.00026±0.00012 and 0.0001±0.00092 mg/dm3, respectively; p<0.05). The specific immune response to N-nitrosodimethylamine exposure was manifested in an increase in the level of specific serum IgG (2 times higher than that in the reference group). An increase in the specific sensitivity to N-nitrosodimethylamine (by the criterion of IgG) was observed in 60.7% subjects. A correlation was found between an increase in the level of IgG to N-nitrosodimethylamine and rise in the concentration of N-nitrosodimethylamine in the blood (R 2 =0.35; p=0.021). Under these conditions the spontaneous and induced production of arachidonic acid metabolites (leukotrienes) increased by 2.1 times, while the expression of p53 transcription factor (responsible for oncosuppression) decreased by 1.9 times as compared to those in the reference group (p<0.05).

[Determination of phthalates in juice product by high-performance liquid chromatography/mass spectrometry].

The paper presents the research results obtained after determination of the persistent organic pollutants of the environment - phthalates in domestic juice products with the use of high-performance liquid chromatography/ mass spectrometry (HPLC/MS/MS) with application of solid-phase extraction as a method of sample preparation. Selective determination of phthalates in fruit and vegetable juices by HPLC/MS/MS method has been provided through parent and child ions' monitoring that are formed during ionization of the molecules of the studied compounds in the electrostatic spray of isomers on a reversed-phase column. The analysis of the samples of juice product revealed the presence of 11 phthalates out of 13 studied in concentration range from 0.4 up to 59.26 mg/dm3. The maximum amount of phthalates was found in juices with pulp 31.9-59.26 mg/dm3 (tetrahedral package), the minimum content of phthalates 0.4 mg/dm3 was detected in flavoured beverages (polyethylene terephthalate packing) and 1 mg/dm3 in the fruit-and-vegetable nectar (glass packing). The most samples contained from 3 to 8 phthalates with total content of 0.4-5.82 mg/dm3. The most prevailing pollutants of the analyzed samples were di-n-octyl phthalate found in 100% of samples, dinonyl phthalate and di (2-ethylhexyl) phthalate, presented in 70-80% of samples. The maximum pollution density of the juice samples was noted for di-n-octyl phthalate, di (2-ethylhexyl) phthalate, diisononyl phthalate and diisobutyl phthalate.

[Determination of N-nitrosodiphenylamine in meat canned food for children by the method of chromato-massspectrometry].

This study demonstrates the results obtained from the GC/MS experimental determination of low concentrations of N-nitrosodiphenylamine in meat canned baby food in the concentration range of 0.027-3.89 mg/kg. The perfect conditions of sample preparation (extraction with organic solvent and solid phase extraction) as well as the application of the chromatography-mass spectrometry allowed us to detect N-nitrosodiphenylamine in samples of the meat canned baby food with high selectivity in concentrations ranged from 0.016 to 5 mg/kg when an error of 23% was assumed. The use of the reaction of transesterification of fatty acids by potassium methylate, the removal of the ester generated from the samples of canned meat by organic solvent (hexane), concentrating of N-nitrosodiphenylamine in the aqueous layer on the cartridges of an automatic solid-phase extraction system provided 99.94% extraction of N-nitrosodiphenylamine from the canned meat samples. The experiment has made evident the presence of N-nitrosodiphenylamine in the samples of canned meat (beef + chicken) with the help of mass-spectrometry method in the mode of full ion scanning using the AMDIS automatic mass-spectral identification system.

[Evaluation of contamination levels of serum and expired air of mechanical rubber production workers exposed to acrylonitrile at work].

To evaluate occupational hazards for workers engaged into mechanical rubber production, the authors determined contents of acrylonitrile in serum and expired air, during occupational exposure and in reference group. Findings are that depending on occupation, age and length of service, acrylonitrile contamination level of expired air has intermittent effect. Main occupations workers are exposed to continuous inhalation of acrylonitrile vapors, with its average concentration of 0.01-0.015 mg/m3 in air of workplace. Acrylonitrile concentration in expired air of this group ranged from 0.0001-0.0009 mg/M3 - that is reliably (p <0.05) higher (5.5 times) than in expired air of the reference group members. Serum levels of acrylonitrile did not differ significantly between the main group and the reference group members.

[Control of highly toxic N-nitrosamines (N-nitrosodimethylamine and N-nitrosodiethylamine) content in baby's cereals].

This paper proposes gas chromatography-mass-spectrometry method for determination of N-nitrosamines (N-nitrosodimethylamine and N-nitrosodiethylamine) in dry baby cereals (milk and milk-free). According to the results of the experimental studies, the method of sample preparation has been substantiated. This is the method of distillation with superheated steam, concentration of distillate on cartridges of automatic system of solid phase extraction. Optimal conditions for chromatography-mass spectrometry analysis has been selected (GC/MS). Analysis of the cereals (milk and milkfree) on the content of N-nitrosodimethylamine and N-nitrosodiethylamine in concentration range 0.0055-0.0109 mg/kg allowed to determine high content of the determined components by the sum of N-nitrosamines in cereals' samples of different manufacturers: oatmeal with milk, buckwheat with milk, oatmeal with milk and banana, milk-free maize cereal. In the multigrain milk cereal and buckwheat with milk, peaches and apricots the content N-nitrosamines was not detected (0.0004-0.00066 mg/kg). To confirm the presence of N-nitrosamines identified in a sample of oatmeal with milk, the identification in SCAN mode has been performed. Mass-spectrum of N-nitrosodimethylamine and N-nitrosodiethylamine in examined samples were compared with massspectrums that were included in library bank of mass-spectral data NIST 08.L.

[Possibilities of submicron objects study in blood of workers].

The article contains results of studies characterizing nanoparticles in blood and serum of exposed workers engaged into titanium and magnesium production and workers outside coverage of occupational factors. Comparative study of the workers' serum included dynamic light dispersion, scanning electronic microscopy, transmission electronic microscopy. Measuring despersion characteristic of blood serumin the workers exposed to nanomaterial revealed increased percentage of particles with hydrodynamic diameter within 60-100 nm and over 100 nm.

[Determination of strontium content in whole blood and urine by icp-ms].

Parameters of strontium determination in the whole blood and urine of children living near ore deposits containing up to 20% strontium sulfate have been determined. The average strontium content in the whole blood of two children groups of 109.52 ± 11.07 mg/L and 131.62 ± 12.95 mg/L, significantly exceeded the level in the comparison group 44.2 ± 4.24 mg/L. The average strontium contents of two groups of children in urine were 1252.3 ± 332.2 mg/L and 1341.5 ± 241.8 mg/L, these values were 4.2 and 4.5 times higher than in the comparison group 296.4 ± 61.5 mg/L. The conditions for blood and urine sample preparation were optimized to reduce measure errors and to determine strontium at the reference concentration level. The accuracy of the results has been confirmed by analysis of the standard samples Seronorm™ Whole Blood L1, L2, L3 and Seronorm™ Urine.

[THE DEVELOPMENT AND VALIDATION OF THE GAS CHROMATOGRAPHY METHOD AND VALIDATION DEVELOPMENT FOR THE ORGANIC CYANIDE (CYANOETHYLENE) DETERMINATION IN EXPIRED AIR].

There are presented results of experimental studies on the development of gas chromatography method for the cyan ethylene determination in expired air During the process of the study there was chosen and proved the capillary gas chromatography method; there were investigated and elaborated optimal parameters of the gas chromatography separation of cyanoethylene with associated hydrocarbons together with the sample preparation and quantitative measurement methods. There was achieved the optimal level of gas chromatography quantification method for the cyan ethylene determination at 0, 00012 mg/m3, with the method uncertainty not more than 25%. The method was tried during the medical and biological examination of groups of 6-8 years old children, living in the territory of exposition from the moment of the birth and in the control territory.

[The elaboration of gas chromatographic method of the determination of N-nitrosamines (N-nitrosodimethylamine, N-nitrosodiethylamine) in biological samples (urine)].

The issues of the elaboration of a method for the determination of N-nitrosamines (N-nitrosodimethylamine, N-nitrosodiethylamine) in urine by means of the method of capillary gas chromatography with the use of a thermionic detector are considered. There were performed investigations on the study of the efficacy of the extraction of N-nitrosamines from the urine by steam distillation and gas chromatographic detection of headspace. With the aim of the maximal recovery of N-nitrosamines from the urine and setting parameters of the extraction two method were used to prepare the bioassay for the analysis the alkalization with potassium hydroxide and the addition of salting out reagent--neutral salts of alkali and alkaline earth metals. During the process of performed studies there was found that the greatest degree of extraction of N-nitrosamines from the urine by the method of headspace analysis is achieved if using the salting-out agent in an amount of 16 g of sodium sulfate and for N-nitrosodimethylamine is 99%, for N-nitrosodiethylamine--100%.

[Peculiarities of vanadium determinaion in whole blood by ICP-MS].

The parameters of vanadium determination by ICP-MS in whole blood are presented. Conditions for blood sample preparation to reduce measure errors and to determine vanadium at the reference concentration level were optimized. The accuracy of the results is confirmed by analysis of standard blood samples Seronorm L1, L2 and L3. Vanadium mean in whole blood for the group of children from the town of Chusovoy (n = 80) was 1.29 +/- 0.45 microg/L, and vanadium mean for grown-ups from the town of Chusovoy was 1.63 +/- 0.25 microg/L.

[Methodical ware for the hygienic risk assessment of vanadium exposure to the children's health].

In the article there is considered the complex of methodological approaches for the detection of vanadium in the air and biological substrates of the population for the practical use in the frameworks of public health monitoring in areas with localization of steel industry facilities. The developed complex of methods on the base of mass spectrometry with inductively coupled plasma (ICP-MS) allowed to perform the hygienic assessment of the quality of objects of the environment in the territory located in the zone of the impact of emissions of ferrovanadium production (the city of Tchusovoy of the Perm Krai). From the results of the study there was established the significant excess of the vanadium content in the ambient air of the studied area in relation to the control territory and to the reference concentration for chronic inhalation exposure (RfCxp) to 6.0 times. There was revealed a significant excess of vanadium content in the blood of children residing in the study area, with respect to the regional background levels (0.0001-0.00016 mg/dm3). Complex clinical laboratory and chemical-analytical studies of biosubstrates of the children population allowed to substantiate the marker of the inhalation exposure (the vanadium content in the blood) and its reference level (0.0023 dm3).

[Results obtained in evaluation of parameters characterizing air-borne nanoparticles at a titanium-production facility].

To reveal, identify and evaluate nano-particles content, the authors performed screening studies of nano-particles in the air of workplace contaminated with aerosol coming from high-temperature titanium smelting. The studies involved diffuse spectrometry, scanning electronic microscopy, energy dispersion analysis, mass spectrometry with inductively coupled plasma. Objects identified are nano-particles with average aerodynamic diameter ranging 35.5 - 71 nm, mostly rounded shape, chemically close to titanium oxide, counted concentration of them varied from 86 to 360 billion particles per cubic meter.

[Determination of phthalic anhydride in ambient air by high performance liquid chromatography].

The paper considers the measurement of phthalic anhydride in the ambient air samples by high performance liquid chromatography. It describes conditions for air sampling and analysis of phthalic anhydride levels in the presence of concomitant components of its production (phthalic and maleic acids, maleic anhydride, etc.) on a liquid chromatograph with an UV detector. The procedure was tested, by estimating the quality of ambient air at the border of a sanitary protection zone of phthalic anhydride production and when analyzing the air in the industrial area. Field studies detected the concentrations of phthalic anhydrate in the air of an enterprise area, which were equal to 0.017-0.115 mg/dm3. Phthalic anhydride was detectable at a concentration of 0.001-0.0021 mg/dm3 at the border of the existing sanitary protection zone in single cases. The procedure has been recommended to measure the mass concentrations of phthalic anhydride aerosol and vapors in ambient air at the reference concentration.

[Substantiating the blood concentrations of phenol and alkylphenols (o-, m-, and p-cresols) providing the acceptable risk to human health].

The paper considers the current nontraditional approaches to revealing the causal effects and criteria for significance of an exposure-response relationship. The study has used the elements of methodology for assessing the risk and the techniques of environmental epidemiology to examine causal effects. A blood toxicant-response marker relationship was assessed and the quantitative characteristics of the association between the concentrations of the test compounds and the risk of noxious effects were ascertained. On the basis of exposure marker-response marker models, the authors revealed the priority types of functional changes and established the blood concentrations of phenol and m- and n-cresols at an acceptable risk level.

[Determination of volatile fatty acids in blood for the evaluation of multiple-factor environmental exposure].

The paper considers problems in the assay of volatile fatty acids in blood by capillary gas chromatography using a flame ionization detector. The blood levels of different volatile fatty acids were analyzed in children with environment-induced chronic gastroduodenitis with secretory failure. The performed studies allowed the authors to recommend that the altered blood levels of volatile fatty acids as an indicator of the environment-modified influence of poor environmental factors on the course of the disease.