[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.

[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.

[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.