Развитие мицеллярной жидкостной и тонкослойной хроматографии.

The comparative study of micellar TLC and RP-TLC as potential tools for lipophilicity assessment based on QSRR approach

A review of applications of micellar liquid chromatography (MLC) with special stress upon micellar thin layer chromatography (MTLC) in drug discovery is given. MLC and MTLC are presented as valuable sources of information on the physicochemical properties (mainly lipophilicity) of solutes and as tools to predict their biological activity: interactions with biomembranes, blood-brain barrier permeability, plasma protein binding, volume of distribution, gastric, ocular and skin absorption, environmental toxicity and bioaccumulation. The results of modeling based on the MLC/MTLC descriptors are correlated with those obtained by other in vitro, in vivo or in silico techniques used to study bioavailability. The future prospects of MTLC application in drug discovery and safety assessments of environmentally hazardous compounds are discussed.

The separation selectivity of eighteen phenolic derivatives in micellar high-performance liquid chromatography was studied as a function of parameters on which it depends: surfactant and organic modifier concentration. The surfactant used in this study was cetyltrimethylammonium bromide, and as organic modifier methanol. An iterative regression optimization strategy for these two parameters has been used. The equation that best explains the experimental results is 1/k' = A +Bμ + Cφ + DμΦ. We propose the use of this model in conjunction with the appropriate factorial design to predict the solute retention behaviour in micellar liquid chromatography with hibrid eluents.

Three environmentally and agrochemicaly important mercury species: methylmercury, phenylmercury and mercury(II) are separated within 4 minutes as bromocomplexes by micellar liquid chromatography using very short reversed-phase (RP) C18 columns (up to 30 mm). The micellar mobile phase containig 0.05M cetyltrimethylammonium bromide (CTMA+Br−), 1% (v/v) 2-propanol, 0.001M cyclohexylenediaminetetraacetic acid (DCTA) and sulfuric acid (pH 2) showed good selectivity in mixed reversed-phase and anion-exchange mode. The above mentioned separation order in which organomercurials are cluted far behind the void volume of the column, but before the mercury(II) peak is advantageous in all instances where mercury(II) is present in real samaples in great excess. Environmental and agrochemical samples contain humic material which does not interfere in this particular system. The low cost photometric detection at 500 nm after post-column derivatization by CTMA+Br− micellized dithizone is almost free from interferences and enables detection limits at the 1–3 ng level (e.g., 0.1 ppm Hg) for 20 μl samples.

Micellar and sub-micellar ultra-high performance liquid chromatography of hydroxybenzoic acid and phthalic acid positional isomers

A simple, sensitive, and precise micellar liquid chromatographic method for simultaneous analysis of sulfamethoxazole and trimethoprim, with ultraviolet detection at 245 nm, has been developed, validated, and used for determination of the compounds in commercial pharmaceutical products. The compounds were well separated on a Hypersil ODS reversed-phase column at 35°C by use of a mobile phase consisting of 0.1M sodium dodecyl sulfate in a 2:98 (V/V) mixture of 1-butanol and pH 3.0 phosphate buffer solution at a flow rate of 1.0 mL min−1. A comparative study of the performance of reversed-phase liquid chromatography with aqueous-organic or micellar-organic mobile phases for separation of sulfamethoxazole and trimethoprim is reported. The study showed that micellar liquid chromatography (MLC) and reversed-phase liquid chromatography (RP HPLC) are of similar efficiency, sensitivity, and selectivity for determination of sulfamethoxazole and trimethoprim.

The article describes tasks that electronic collections of rare books fulfill: broad access for readers to rare and valuable editions providing, preservation of ensuring of the original. On the example of the electronic collection of the Central Scientific Library of the V.N. Karazin Kharkiv National University – « eScriptorium: electronic archive of rare books and manuscripts for research and education» the possibility of the full-text resources of the valuable editions using is shown. The principles of creation, structure, chronological frameworks, directions of adding the documents to the archive are represented. The perspectives of the project development are outlined as well as examples of the digital libraries of the European countries and Ukraine are provided, the actual task of preserving the originals of the rare books of the country is raised, the innovative approaches to serving users with electronic resources are considered. The evidences of cooperation of the Central Scientific Library of the V.N. Karazin Kharkiv National University with the largest world digital libraries: World Digital Library and Europeana are provided.

Micellar liquid chromatography (MLC) has been used to study the lipophilicity of eight newly synthesized N-phenyltrichloroacetamide derivatives. Because the lipophilicity of a substance determines its retention and its interactions with micelles, chromatographic data calculated from experimental results — km (log km) — were compared with partition coefficients log P calculated from the molecular structures of the solutes. Micellar mobile phases containing Brij 35 and tetrahydrofuran, alkyl-bonded stationary phases, and two planar chromatography techniques — thin-layer chromatography (TLC) and over-pressured-layer chromatography (OPLC) — were used in the experiments. According to results obtained from the OPLC studies, especially, log km values are excellent descriptors of the lipophilicity of the compounds. Very good linear relationships between log km and log P were obtained by use of this technique (R in the range 0.917–0.987).

Purpose of the article. The article represents an analysis and publication of the letters of Kharkiv University professor Fedir Shmit (1877–1937?) held in the manuscript collection of the Central Academic Library of V. N. Karazin Kharkiv National University. Methodologically, the study is based on the principles of historicism and objectivity and employs a variety of special historical methods, including chronological, comparative, and the method of internal and external source criticism. Academic originality. Fedir Shmit’s letters to his fiancée Pavla Shper from the library of V. N. Karazin Kharkiv National University, dating to March 1904, are published for the first time. The author analyzes the contents of the scholar’s personal correspondence and the importance of his study of Byzantine artifacts and monuments in Ravenna, undertaken in March 1904, for his subsequent work. Conclusions. The article outlines the significance of Fedir Shmit’s letters from the CAL collection both for reconstructing the scholar’s biography and for assessing his contribution to Byzantinology. Personal correspondence throws light on Shmit’s study of Byzantine remains in Ravenna, the results of which are presented in the works of his Kharkiv period. The author deciphers the letters and provides commentary on individual fragments. The article represents the first publication of Fedor Shmidt’s manuscript legacy preserved in Kharkiv’s libraries and archives.

The purpose of the article is to explore the current experience of geography teacher training in Czechia and Ukraine based on the experience of the University of West Bohemia and V.N. Karazin Kharkiv National University. The main material. In the Czech educational system, becoming a qualified teacher typically involves completing a three-year Bachelor’s program (180 credits) followed by two-year Master’s program (120 credits) while in Ukraine a Bachelor’s program lasts for four years (240 credits) and a Master’s program lasts for one and a half years (90 credits) or 2 years (120 credits). Geography teacher training at the Department of Geosciences of the University of West Bohemia is offered at the Master’s level (following a preparatory Bachelor’s program) and allows for combinations with other teaching subjects. The Bachelor’s program in Geography for Education emphasizes academic preparation in geographic and pedagogical founda­tions, preparing students for advanced study. It includes fieldwork, a research-based thesis, and a state exam. The follow-up Master’s program focuses heavily on geography teaching methodology and includes regionally oriented subjects, three stages of pedagogical practice, and innovative training using a virtual reality-based classroom simulator. The final state exam uniquely simulates real teaching, requiring students to demonstrate both their geographic knowledge and teaching competencies. Geography teacher training at the School of Geology, Geography, Recreation and Tourism of V.N. Karazin Kharkiv National University is offered at both Bachelor’s and Master’s levels through specialized programs combining geographic, pedagogical, and practical components. The Bachelor’s program prepares students to teach Geography, Nature Study, and Economics, focusing on core geographic knowledge, pedagogy, and substantial fieldwork. The Master’s programs offer two tracks – one with a natural science focus and another with an economic orientation – allowing students to deepen their expertise and teaching skills. Both levels emphasize pedagogical practice and conclude with the public defense of a thesis. Conclusions. The analysis of geography teacher training in Czechia (University of West Bohemia) and Ukraine (V.N. Karazin Kharkiv National University) demonstrates both the progress that has been made and the challenges that remain. Both countries have established strong foundations for preparing future geography teachers, with a focus on integrating pedagogy and content knowledge, practical experience, and fieldwork. Looking ahead, further modernization of curricula, increased use of VR technology, and international cooperation will be key to ensuring that geography teachers are well-prepared to meet the demands of 21st-century education.

На території Ботанічного саду Харківського національного університету (ХНУ) ім. В. М. Каразіна на хвойних породах визначено 4 види короїдів: короїда-типографа (Ips typographus L.), гравера звичайного (Pityogenes chalcographus L.), соснового короїда-крихітку (Crypturgus cinereus Herb.) та тайгового короїда-крихітку (C. subcribrosus Eg.). Відзначено, що з роду Abies лише п’ять видів не мали ознак заселення, а саме: A. balsamia, A. cephalonica, А. concolor, A. grandis, А. violacea. Picea koraiensis та P. alba не були заселені короїдами, але на стовбурі помічено спроби заселення. Встановлено, що форму P. obovata «Glauca» заселяли всі визначені види короїдів. Найбільш поширеним на ялині серед інших видів короїдів виявився Ips typographus. Серед 198 обстежених дерев визначено: живих із відсутністю ознак заселення короїдами – 27,3 %, зі спробами заселення – 9,1 %, заселених короїдами – 63,6 %.

The purpose of the work is to highlight the information-synergistic component of human-geographical research through the analysis of the scientific heritage of Kostiantyn Niemets – Honored Professor of V.N. Karazin Kharkiv National University. The achievement of the set purpose was accomplished through revealing the figure of the scientist Kostiantyn Niemets, justification of the human-geographical approach based on the information-synergistic paradigm, highlighting the formation of the concept of sociogeosystem and the sociogeoprocess, the peculiarities of the implementation of ideas in the educational process, the training of specialists and scientists, highlighting the potential of human geography and the information-synergistic component of human- geographical research in accordance with today's challenges. Results. This article presents an analysis of the information-synergistic component of human- geographical research in the scientific heritage Kostiantyn Niemets – Honored Professor of V.N. Karazin Kharkiv National University. The role of the synergistic paradigm is defined as the basis of modern science and scientific research. The implementation of the synergistic concept in sociogeosystems research, the definition of the role of the information resource and the features of information exchange are substantiated. The main contradictions between society and nature are revealed; the structure of the sociogeoprocess is considered; the main principles of the interaction of society and natural systems in the multi-system of nature management are revealed. The ideas of the formation of the concept of sociogeosystems and sociogeoprocess are highlighted and the features of the implementation of ideas in the educational process of V.N. Karazin Kharkiv National University. are revealed. An analysis of the scientific heritage, which is realized in the scientific research of students and followers of Kostiantyn Niemets, is presented. The latest research and publications were analyzed, in particular, theoretical and methodological developments, the research toolkit, which was introduced during the implementation of dissertations for obtaining the scientific degree of doctor and candidate of geographical sciences under the leadership of Kostiantyn Nemets, as well as during the implementation of scientific research developments, projects and grants, powerful scientific publications authored by Kostiantyn Niemets. The article shows his huge contribution to the development of scientific research and support of young people. The results of the analysis of the dissertation works, which were created under the leadership of Kostiantyn Niemets, and the features of the introduction of the human-geographical approach and the use of powerful mathematical apparatus and modeling methods in these works are presented. Today, the synergistic paradigm is becoming one of the most important foundations of modern science and is being widely implemented in all fields of scientific research. The synergetic paradigm arose at the junction of many fundamental directions of science in the second half of the 20th century, its main methodological premise is a fundamentally different and unconventional understanding of the development of phenomena, processes, and systems in the surrounding reality. In contrast to the classical interpretation of development as a linear process, synergetics interprets the concept of development as a non-linear process that occurs as a result of the interaction of a large number of factors of different nature. In this regard, human geography occupies a leading place, because the main object of its research – the sociogeosystem – combines natural and social subsystems; therefore, human- geographical research includes all aspects of a synergistic approach.

The amount of sodium dodecyl sulfate (SDS) adsorbed on a reversed-phase octadecylsilica (ODS) stationary phase in micellar liquid chromatographic (MLC) separation has been measured. It was found that the weight percentage of SDS on the stationary phase (16.5%) was similar to the percentage ratio of C/Si (C/Si = 17.1%) of the original ODS stationary phase. This indicated that the octadecyl groups of the ODS packing were largely covered by adsorbed surfactants and the stationary phase in the MLC system could be considered to be the adsorbed surfactant. Accordingly, a new three-phase equilibrium model in which the adsorbed surfactant was assumed to be the stationary phase was proposed to illustrate the behaviour of analyte partitioning in MLC. The negative impact of the adsorbed surfactant on the efficiency of MLC was discussed in terms of this new model. With the three-phase model, the equilibrium constant (K3) for direct transfer of the analyte from the surfactant in the mobile phase to the surfactant on the stationary phase could be calculated. The results obtained for K3 using two model analytes showed that the mobile phase and stationary phase portions of the surfactant in MLC had similar but not identical abilities for binding the analyte. The effects and limitations of the use of organic modifiers in MLC are also discussed.

Optimization of the separation selectivity of a group of benzene and naphthalene derivatives in micellar high-performance liquid chromatography using a C18 column and alcohols as modifiers in the mobile phase

Micellar liquid chromatography of proteic primary amino acids with pre-column derivatization with o-phthalaldehyde (OPA) and N-acetyl-L-cysteine was studied, using mobile phases containing a short-chain alcohol. The modification of pH gave a large variation of the retention as a result of the protonation of the carboxylate group of amino acids. Maximum resolution and adequate retentions were achieved with a 0.05 M sodium dodecyl sulphate/3% propanol mobile phase at pH 3. The reproducibility was lower than 1.0% at a 1 × 10−4 M concentration level and between 0.6 and 2.2% for 1 × 10−6 M. The determination of glycine, lysine, methionine and threonine in pharmaceutical formulations gave recoveries, with respect to the values declared by the manufacturers, in the 90–105% range.