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To expand the field of application of anion exchangers based on a copolymer of styrene and divinylbenzene with attached polyethyleneimine, quaternized with glycidol, the following conditions for their synthesis were varied: the amount of the added glycidol, temperature, and duration of synthesis. The influence of these factors on the capacity, selectivity, and efficiency of the resins in the mode of suppressed ion chromatography was studied; in addition, the stationary phases were studied in the mode of hydrophilic interaction liquid chromatography using the Tanaka test. It was shown that the synthesis conditions under study ensure the control of the capacity and selectivity of anion exchangers, while their hydrophilicity changes insignificantly. The behavior of oxoanions on covalently attached resins in the ion chromatography mode was studied for the first time, and the applicability of phases with quaternized polyethyleneimine in the hydrophilic interaction liquid chromatography mode to the separation of sugars, amino acids, water-soluble vitamins, nucleosides, and nitrogenous bases was demonstrated for the first time., Author(s): A. V. Gorbovskaya [sup.1] , E. K. Popkova [sup.1] , A. S. Uzhel' [sup.1] , O. A. Shpigun [sup.1] , A. V. Zatirakha [sup.1] Author Affiliations: (1) grid.14476.30, 0000 [...]

A domestic composite material based on silicon carbide and nitrile butadiene rubber was used to identify volatile substances of banana, banana flavor, and creamy chewing candies by passive adsorption in combination with thermal desorption GC-MS. This method can be used to determine a wide range of compounds, for example, esters of carboxylic acids, terpenoids, aldehydes, aromatic hydrocarbons, alkanes, heterocyclic compounds, phenols, glycerides, and fatty acids. The obtained chromatographic profiles of the samples were compared. In the chromatogram of 'Banana' flavor, five peaks (out of eight) corresponded to the compounds that form the aroma of a banana, and in the chromatogram of 'Love is' candies with banana flavor, three corresponding peaks (out of 21) were found., Author(s): E. S. Markova [sup.1] , A. N. Furman [sup.1] , S. P. Shekhtman [sup.1] , A. V. Pirogov [sup.1] , M. V. Popik [sup.1] , O. A. Shpigun [sup.1] [...]

Stationary phases based on silica modified with polyvinylpyridine and polyethyleneimine of different structures using 1,4-butanediol diglycidyl ether as a spacer are obtained. The study and comparison of the chromatographic properties of sorbents modified with polyamines and polyethylene glycol are performed using the Tanaka test for hydrophilic stationary phases and via the separation of model mixtures of sugars, amino acids, and water-soluble vitamins. It is shown that the nature and structure of the polymer in the functional layer affect both the selectivity and efficiency for polar compounds in hydrophilic interaction liquid chromatography mode., Author(s): A. S. Popov [sup.1] , G. S. Maksimov [sup.1] , O. A. Shpigun [sup.1] , A. V. Chernobrovkina [sup.1] Author Affiliations: (1) grid.14476.30, 0000 0001 2342 9668, Department of [...]

A simple, rapid, and sensitive method is developed for the simultaneous determination of hydrazine, methylhydrazine, and 1,1-dimethylhydrazine in waters based on precolumn derivatization with benzaldehyde and the determination of the resulting products by reversed-phase HPLC with spectrophotometric detection at 300, 282, and 298 nm, respectively. The effect of imine and micellar catalysis is applied for the first time to obtain hydrazine derivatives on their simultaneous presence. The conditions of derivatization are chosen: the type, pH and concentration of the buffer system; the concentration of the reagent and the surfactant; and the temperature and duration of the reaction. It is found that the derivatization reaction proceeds completely at pH 9.4 in the presence of a catalytic system based on 0.6 M ammonium and 87 mM sodium dodecyl sulfate, and also 3.5 mM reagent at room temperature for 5 min. The quantitative yield of the derivatization products is confirmed by ion chromatography. The limits of detection (S/N = 3) without additional preconcentration are 0.3, 2.3, and 1.3 [mu]g/L, and the linearity range is 1-500, 7-1000, and 5-1000 [mu]g/L for hydrazine, methylhydrazine, and 1,1-dimethylhydrazine, respectively., Author(s): Yu. V. Timchenko [sup.1], A. V. Apenkina [sup.1], A. D. Smolenkov [sup.1], A. V. Pirogov [sup.1], O. A. Shpigun [sup.1] Author Affiliations: (1) grid.14476.30, 0000 0001 2342 9668, Department [...]

An adsorbent for HPLC, silica doubly layer-by-layer modified with 6,10-ionene and dextran sulfate, is obtained. The adsorbent has both hydrophobic and hydrophilic and ion-exchange properties (because of the presence of hydrophobic anions and cations on the surface). A possibility of using the obtained adsorbent in HPLC with tandem mass spectrometric detection is shown. The conditions for the separation of caffeine, paracetamol, doxylamine, and chlorpheniramine in the isocratic mode are selected in elution with mixtures of acetonitrile and an acetate buffer solution. The most successful results are achieved by eluting the separated substances with the mobile phase acetonitrile-15 mM acetate buffer solution (glacial acetic acid/ammonium acetate with pH 5.55 in the ratio 10 : 90, vol). Gradient elution conditions are selected, a methodology is developed for determining traces of pharmaceuticals in human serum in the multiple reaction monitoring (MRM) mode using the internal standard method. The source and MRM transition parameters are selected individually for each compound. The linear range of the calibration curve for paracetamol and caffeine is 0.5-200 ng/mL and for doxylamine and chlorpheniramine, 0.05-50 ng/mL. The concentration of pharmacologically active compounds of caffeine, paracetamol, doxylamine, and chlorpheniramine in the blood serum of patients taking appropriate drugs is 165.2, 17.3, 10.2, and 35.3 ng/mL, respectively., Author(s): A. N. Ioutsi [sup.1] [sup.2], V. A. Ioutsi [sup.2] [sup.3], E. N. Shapovalova [sup.2], O. A. Shpigun [sup.2] Author Affiliations: (1) grid.415738.c, 0000 0000 9216 2496, Scientific Centre for [...]

The review surveys the works of staff members, students, and graduate students of the Divison of Analytical Chemistry, Department of Chemistry, Lomonosov Moscow State University on the use of microemulsions in liquid and electrokinetic chromatography. Microemulsions are used as promising extractants for the extraction of hydrophobic target substances from food, pharmaceutical, environmental, etc., samples. The possibility of the subsequent separation of microemulsions and the preconcentration of components to be determined in an organic phase was demonstrated. The approaches proposed are characterized by low detection limits; they considerably simplify a sample preparation process to shorten the total analysis time and to decrease the total number of stages, which decreases the error of determination., Author(s): A. V. Pirogov [sup.1], O. A. Shpigun [sup.1] Author Affiliations: (1) grid.14476.30, 0000 0001 2342 9668, Moscow State University, , 119991, Moscow, Russia Hoar and Schulman [1] were the [...]

s The review covers the research of the Laboratory of Chromatography of the Division of Analytical Chemistry of the Department of Chemistry of Moscow State University in the development of new stationary phases for hydrophilic interaction liquid chromatography and ion chromatography performed in 2007-2017. The principles that guided the team in selecting matrices for each type of adsorbents, approaches to the modification of surface, and the methods of forming functional layers are discussed. The revealed regularities of changes in the chromatographic properties of materials on varying the structural fragments of the functional layers are described in detail, which enabled the authors to develop approaches to obtaining stationary phases that are not inferior to commercial analogs in efficiency and selectivity., Author(s): A. V. Zatirakha [sup.1] , A. S. Uzhel [sup.1] , A. A. Loshin [sup.1] , A. V. Chernobrovkina [sup.1] , A. D. Smolenkov [sup.1] , O. A. Shpigun [sup.1] [...]