The methodical peculiarities of methods for the determination of chemical compounds and elements in biological matrices are considered. There are presented examples of practical application of methods for the sample preparation - organic solvent extraction, derivatization, solid-phase extraction, headspace analysis. On the example of the method for the determination the methyl-tret-butyl-ether in blood there is denoted the problem and shown the necessity of the identification of components of biological matrix with the use of the chromato-mass-spectrometry. There are presented examples for the use of the set of factors in order to increase the sensitivity and selectivity in detection of target components.

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Since the middle of the 20th century phthalates have been widely used in food products package manufacturing. But here phthalates turned out to migrate from this package into the environment. There are some data on unfavorable impacts exerted by orally introduced phthalates on the liver and hormonal system. Milk packed in polymer package which contains various plasticizers including phthalates is widely spread on the Russian consumer market. It determined our research goal which was to assess consumers health risks related to impacts exerted by phthalates introduced with milk packed in polymer package. We selected 25 milk samples out of milk products bought in retail networks. Phthalates were quantitatively determined in milk via highly efficient liquid chromatography. We performed a distribution questioning to assess quantity and volumes in which milk was consumed and to determine a share of milk packed in polymer package. We detected that 57 % adult respondents, 75 % children aged 4-6, and 80 % children aged 7-17 consumed milk packed in polyethylene film and (or) in plastic bottles. 5 phthalate forms were identified in consumed milk. Adults actually consumed 0.6 liter of milk per day; children aged 4-6, 0.2 liter; children aged 7-17, 0.3 liter. Phthalates dose introduced daily with milk was equal to 5.61•10-2 mg/kg of body weight for children aged 4-6; 6.32•10-2 mg/kg of body weight for children aged 7-17; 4.20•10-2 mg/kg of body weight for adults. We calculated a lifelong risk and revealed that it occurred due to di-2-ethylexylphthalate when milk packed in polyethylene film and plastic bottles was consumed. Risk-characterizing hazard indexes reached 1.85 for the liver and endocrine system regardless of package.

Among the persistent organic pollutants of atmospheric air, a special place is occupied by a group of polycyclic aromatic hydrocarbons (PAHs) or polyarenes due to their high carcinogenic hazard. In view of the ubiquitous presence of these substances in the atmospheric air, low values of hygienic standards and values of reference concentrations (RfC) for chronic inhalation exposure, the qualitative and quantitative identification of PAHs is the critical task. Purpose is to analyze modern methodological approaches used in laboratory practice to determine polyarenes in atmospheric air on the base of Russian and foreign sources. The paper considers modern methods for the analytical control of PAHs in atmospheric air, officially approved in the Russian Federation and presented in the world literature. The search for literary sources was carried out using the PubMed, RSC Publishing, Springer Nature, SCOPUS, eLIBRARY.RU databases. An analysis of the methodological and scientific and technical literature on methods for the determination of PAHs in atmospheric air made it possible to identify the main directions of methodological developments used in modern laboratory practice for the analytical control of polyarenes in air. The advantages and disadvantages of specific methods, individual stages of analysis, conditions for sampling, storage and transportation of samples, which together can lead to false positive or false negative results, are presented. Conclusion. Modern methods for the analysis of polyarenes in atmospheric air are the result of continuous improvement in the technique of performing individual analytical procedures, the development of new methodological approaches to solving analytical problems, the emergence of new, more advanced measuring and auxiliary equipment, which makes it possible to develop highly sensitive and highly selective methods for measuring toxicants in the human environment at the level of MPCdaily average, MPCone-time and RfC for chronic inhalation exposure.

Phthalates (esters of phthalic acid) are widely used as plasticizers in polymer materials production and it has resulted in substantial contamination with phthalates as they occur in environmental objects, food products, drinking waters, and human biological media. Toxic effects produced by phthalates lead to functional disorders in the endocrine system and synthesis of insulin, phthalates have reproductive toxicity, they cause allergenic reactions and bronchial asthma in children as well as some other diseases. Food products are a primary source of influences exerted by phthalates on population health, first of all, children. To assess risks related to adverse effects by phthalates on children, it is necessary to obtain data on concentrations of these substances in food products aimed for children nutrition. In order to work out a highly sensitive and selective technique for determining phthalates in children nutrition, the authors performed an overview of scientific and technical literature that focused on techniques for determining phthalates in products for infant nutrition (milk mixtures, milk cereals, and canned meat). It was detected that gas and liquid chromatography together with mass spectrometry were widely applied to analyze phthalates in children nutrition; several techniques were applied for samples preparations to exert direct influence on measurements sensitivity and precision. It is still vital to determine how to efficiently extract phthalates with conventional and up-to-date extraction techniques and how to purify them from complicated food matrixes, first of all, milk and vegetable fats that can be found in products aimed for children nutrition. There is a still a problem related to secondary contamination of samples with phthalates due to their occurrence in the air inside laboratories, reagents, solvents, etc., and it needs to be solved. Basing on the analysis of all the reviewed data, we can conclude that it is necessary to work out highly sensitive, selective, and highly precise techniques for determining phthalates in products aimed for children nutrition with new methodical tools for samples preparation taking into account a matrix effect which is specific for certain products as well as risks related to secondary contamination of samples in the process of their preparation and analysis.