[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.

[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 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.

[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.

[Thyroid state in workers of mechanical rubber production under complex exposure to occupational factors].

Complex study of thyroid gland covered workers engaged into mechanical rubber production, under exposure to complex of occupational factors. Chemical analytic study revealed 5.5 times excess of acrylonitrile content of expired air in examinees of the study group if compared to the reference group. Ultrasound examination data demonstrate structural changes in thyroid gland in 72% of the workers (diffuse changes and nodular masses). As early dysadaptation markers, findings are 1.3-1.7 times increased antibodies to TPO and higher TSH level. These disorders can indicate autoimmune processes in thyroid tissue and strain of compensatory adaptational mechanisms of pituitary-thyroid regulation.

[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%.

[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.