Sergey Aleksandrovich Sypalov

Introduction. The international community’s positioning of microplastics (MP) in water as a new health hazard has determined the relevance and formed the basis of the research objective based on literature data and the results of own sanitary-chemical and sanitary-microbiological experiments to develop a programme of analytical and toxicological studies that will justify the indicators and criteria for assessing the danger of MP as necessary to determine its safe level in water.Material and methods. The research material consisted of 5 mm granules of primary MP made of polystyrene (PS) and polyethylene terephthalate (PET). The granules were ground and the particles divided into fractions of 0–100, 100–250 and 250-500 µm. Publications were searched using the scientific literature databases MedLine/PubMed/PubChem, Scopus, and eLIBRARY. Sanitary-bacteriological and sanitary-chemical methods were used, as well as the TFME-GC-MS method – a combination of solid-phase microextraction and gas chromatography with mass spectrometric detection, laser diffraction (LD) and dynamic image analysis (DIA).Results. Experiments to determine the size and morphology of microplastic particles allowed considering optical methods, including LD and DIA, as promising for determining MP in water. In model water bodies, MP from PS at a concentration of 100 g/L created favourable conditions for the development of microorganisms and stimulated BOD processes. In chlorinated samples with MP, 50 substances were identified, 13 of which are potential products of MP chlorination from PET, some of which have long-term toxic effects. Under the conditions of this experiment, the largest number of substances whose peak area increased after chlorination was observed when treating a sample with an MP concentration of 10 g/L.Limitations. Insufficient representative data from experimental studies on the toxicity and hazard of MP for warm-blooded animals in scientific literature databases.Conclusion. An MP research programme has been developed on the base of the methodology for regulating harmful substances in environmental objects, will make it possible to establish the indicators and criteria for assessing the hazard of MP necessary to determine its safe level in water.Compliance with ethical standards. The trial does not require the submission of the conclusion of the Committee on Biomedical Ethics.Contribution: Tulskaya E.A. – concept and design of the study, gathering material, editing; Sinitsyna O.O. – concept and design of the study, editing; Kalyuzhin A.S., Ryashentseva T.M., Borisova N.A., Sypalov S.A. – gathering material, data analysis; Turbinsky V.V., Trukhina G.M., Pushkareva M.V. – concept and design of the study, editing. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.Conflict of interest. The authors declare no conflict of interest.Funding. The study had no sponsorship.Received: November 25, 2025 / Accepted: December 2, 2025 / Published: February 10, 2026

Detecting and quantifying disinfection by-products (DBPs), especially brominated species (Br-DBPs), is analytically challenging, often necessitating multiple techniques and specific standards for each target. This complexity hinders comprehensive assessment. To overcome these limitations, we present a powerful, integrated approach combining liquid chromatography with inductively coupled plasma mass spectrometry (LC-ICP-MS) and high-resolution mass spectrometry (LC-HRMS). This method enables rapid, non-targeted group screening of Br-DBPs: LC-ICP-MS selectively identifies bromine-containing compounds, while LC-HRMS provides tentative structural identification. Crucially, this synergistic combination allows for the quantification of any Br-DBP without requiring individual reference standards. This study successfully demonstrates the application of this combined LC-ICP-MS and LC-HRMS strategy for the non-targeted detection, identification, and subsequent quantification of Br-DBPs in real drinking water samples, offering a significant advancement for DBP monitoring and risk assessment.

Кокамидопропилбетаин (КАПБ) — амфотерное поверхностно-активное вещество, широко используемое в средствах личной гигиены и чистящих средствах, в том числе для плавательных бассейнов. КАПБ, присутствующий в воде бассейна, может выступать в качестве прекурсора для образования побочных продуктов дезинфекции в условиях водного хлорирования. В настоящем исследовании разработан подход к высокочувствительному определению основных компонентов кокамидопропил бетаина в воде бассейна с использованием метода высокоэффективной жидкостной хроматографии с масс-спектрометрическим детектированием высокого разрешения (ВЭЖХ-МСВР). Применение твердофазной экстракции в качестве метода пробоподготовки позволило достичь пределов обнаружения на уровне 0.1 нг л-1. Разработанный подход успешно апробирован при анализе реальных образов воды бассейна. Полученные данные демонстрируют, что в экстрактах воды бассейна присутствуют все целевые аналиты, концентрации которых находятся в диапазоне от 0.90 ± 0.10 до 124 ± 6 нг л–1. Это обуславливает необходимость регулярного мониторинга содержания КАПБ в воде бассейнов и разработки санитарно-гигиенических нормативов.

Bromhexine and ambroxol are among the mucolytic drugs most widely used to treat acute and chronic respiratory diseases. Entering the municipal wastewater and undergoing transformations during disinfection with active chlorine, these compounds can produce nitrogen- and bromine-containing disinfection by-products (DBPs) that are dangerous for aquatic ecosystems. In the present study, primary and deep degradation products of ambroxol and bromhexine obtained in model aquatic chlorination experiments were studied via the combination of high-performance liquid and gas chromatography with high-resolution mass spectrometry. It was shown that at the initial stages, the reactions of cyclization, hydroxylation, chlorination, electrophilic ipso-substitution of bromine atoms with chlorine, and oxidative N-dealkylation occur. Along with known metabolites, a number of novel primary DBPs were tentatively identified based on their elemental compositions and tandem mass spectra. Deep degradation of bromhexine and ambroxol gives twenty-four identified volatile and semi-volatile compounds of six classes, among which trihalomethanes account for more than 50%. The specific class of bromhexine- and ambroxol-related DBPs are bromine-containing haloanilines. Seven of them, including methoxy derivatives, were first discovered in the present study. One more novel class of DBPs associated with bromhexine and ambroxol is represented by halogenated indazoles formed through dealkylation of the primary transformation products containing pyrazoline or tetrahydropyrimidine cycle in their structure.

We aimed to determine the distribution of toxic elements amongst the organic components of peat collected from raised bogs located in the Arkhangelsk region of Russia, and thus to gain new insights about the ability of peat to accumulate these elements. We separated peat samples into four fractions (bitumen, humin, humic acids (HA) and fulvic acids (FA)) using phased liquid-liquid extraction. We found that humin was the main component of the peat and its proportion varied from 87.5 % to 90.0 % of total mass. HA, FA and bitumen accounted for 1.7–5.7 %, 2.1–3.8 % and 3.8–5.2 % of the total mass of peat, respectively. Using spectroscopic techniques we found that the humin, HA and FA contained significant concentrations of carboxylic and amino groups capable of forming chemical bonds with elemental ions. Elemental concentrations in the peat fractions were analysed using inductively coupled plasma mass spectrometry (ICP-MS), focusing on the toxic elements arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb) and uranium (U). FA was the most active component in terms of binding trace elements in the peat, while the bituminous fraction had the lowest sorption capacity for all of the elements observed. The accumulation of toxic ions was dependent on the presence and concentration of active chemical centres and proceeded according to the chemisorption mechanism.

Peat was studied in order to assess the concentrations of heavy metals in it depending on the depth of occurrence. Genetically homogeneous peat layers with

Lignin is one of the most abundant biopolymers. Information about the functional composition and structure of various lignins may be useful in the study of biosynthesis processes in plants. The subject of the article is the determination of 31P-NMR spectroscopy possibilities to identify lignins obtained from various plant forms. To obtain spectra on 31P nuclei, a modification of the studied samples was applied by phosphitylating their OH-groups with a special reagent. We obtained qualitative and quantitative analysis of samples of softwood and hardwood lignins and herbaceous plants. According to the NMR spectra we noted the differences in composition and structure of the studied lignins. We confirmed that the structure of lignins of softwood and hardwood wood mainly contain guaiacilpropane and syringylpropane structural units, respectively. We found that lignins of herbaceous plants contain all types of OH-groups characteristic for lignins, including p-hydroxyphenyl groups. It was observed that samples of herbaceous plants lignins contain fragments of flavonoid structures in most cases. The 31P-NMR spectrum of quercetin, as the flavonoids representative, was registered and also modeled using the ACDLabs software package to confirm the presence of flavone structures in the macromolecules of the herbaceous lignins.