Search

We studied the features of PAHs extraction by QuEChERS in the sample preparation of soils and bottom sediments of various compositions followed their determination by gas chromatography-mass-spectrometry. The test samples were soils of sandy, loamy sand, loamy, and clayey types and bottom sediments of loamy sand type. The mineralogical composition and organic matter content of the samples were used to predict how PAHs were retained by the soils and sediments. The impact of ultrasonic treatment on analyte extraction with subsequent identification by chromatography was assessed. No ultrasonic treatment was required to extract and determine all PAHs (up to 100%) in sandy and loamy sand soils and low-molecular-weight PAHs in all test samples. The QuEChERS extraction and determination of high-molecular-weight PAHs in clay type soil samples and loamy sand bottom sediments required a 10-min ultrasonic treatment, while the recoveries of analytes were higher than 87 and 90%, respectively. The analysis of a loamy soil sample with a high organic matter content was the most challenging. To extract over 70% of high-molecular-weight PAHs from a sample of this type using the QuEChERS technique, the binary acetonitrile-acetone (1 : 1) extractant rather than conventional acetonitrile was used with the simultaneous 15-min ultrasonic treatment., Author(s): Z. A. Temerdashev [sup.1] , S. K. Ovsepyan [sup.1] , T. N. Musorina [sup.1] , L. V. Vasileva [sup.1] , A. M. Vasilev [sup.1] , I. G. Korpakova [sup.1] [...]

The results of a study of the composition of essential oil and extracts obtained by hydrodistillation and subcritical extraction from plants of the genus Mentha L. are presented. The test samples were peppermint (Mentha piperita L.) and horsemint (Mentha longifolia L.). Gas chromatography-mass spectrometry was used to identify and compare the component composition of essential oils and extracts from Mentha L. plants. The composition of the essential oil of horsemint differs from the essential oil of peppermint by the high concentration of linalool and the absence of pulegone and piperitone. The component composition of the extracts of peppermint and horsemint, obtained under conditions of subcritical extraction with water and acetone, was studied. The concentration of monoterpenes, sesquiterpenes, and esters increased in the transition from the essential oil to the acetone subcritical extract of both types of mint. In the water extract of peppermint, there were practically no sesquiterpenoids or esters; there was a general decrease in the yield of all components compared to the essential oil and acetone extract., Author(s): D. V. Nazarova [sup.1] , Z. A. Temerdashev [sup.1] , E. A. Vinitskaya [sup.2] , N. V. Kiseleva [sup.1] , M. V. Nagalevskii [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 [...]

Results of a study of water and water-alcohol extracts of wild chamomile (Matricaria chamomilla L.) depending on the conditions of their extraction by different methods are discussed. The test samples are wild chamomile samples collected in various regions of Russia. Phenolic components in their native forms were extracted from medicinal raw materials using infusion, maceration, microwave-assisted, ultrasound-assisted, and subcritical extraction, and by the pharmacopoeial method. Concentrations of individual components and total phenolic compounds in wild chamomile were determined by chromatographic methods. The HPLC determination of phenolic compounds with diode-array and mass spectrometric detection was carried out using gradient elution with a mixture of acetonitrile with 0.1% formic acid. Chlorogenic acid, ferulic acid glycosides, luteolin-7-O-glucoside, dicaffeoylquinic and chicoric acid, apigenin-7-glucoside, and apigenin were identified in water and water-alcohol extracts of wild chamomile. The dependence of the concentration of phenolic compounds on the geographical place of the growth of plant raw materials was studied based on value of this parameter in extracts of wild chamomile samples from different territories. The maximum total concentration of phenolic compounds (10.1 mg/g) was found in the extract of chamomile from FarmaTsvet (Krasnogorsk, Moscow oblast)., Author(s): Z. A. Temerdashev [sup.1] , T. K. Chubukina [sup.1] , E. A. Vinitskaya [sup.1] [sup.2] , N. V. Kiseleva [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Kuban [...]

We proposed a procedure for the simultaneous determination of viscosity improvers and detergent additives in synthetic oils by gel permeation chromatography, including the preliminary liquid extraction of polar additives, solid-phase extraction of polymer additives on silica modified with magnesium oxide from oil raffinate, and the subsequent determination of analytes. The procedure was used to determine viscosity improvers and detergent additives in fresh and used synthetic motor oils, to control the quality of oils at different stages of operation, and to monitor the degree of purification of oils during their regeneration. In-process monitoring of additive concentrations during the operation of automotive equipment enables the timely control of the dynamics of engine oil degradation throughout its use and proper recommendations for its replacement in the system. The procedure was tested in the analysis of fresh and used multigrade synthetic motor oils Shell Helix Ultra 5W-30 and TP MAX Total 10W-40 and fresh multigrade synthetic motor oil Shell Rimula R5M 10W-40., Author(s): Z. A. Temerdashev [sup.1] , Yu. A. Ivanova [sup.1] , D. A. Litvinenko [sup.1] , D. A. Makhotkina [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Department of [...]

We studied the gas chromatographic determination and identification of phenolic compounds in aqueous extracts of St. John's wort (Hypericum perforatum L.) using solid-phase analytical derivatization in the sample preparation for analysis and mass spectrometric detection. A comparative analysis of the results of the determination of phenolic compounds using conventional analytical derivatization in solution and solid-phase analytical derivatization in aqueous extracts of St. John's wort showed that the preparation of derivatives on an adsorbent shortens sample preparation, minimizes the volume of the extract, and expands the list of components to be determined. We found the optimal conditions for the adsorption of phenolic substances from aqueous extracts on the Strata C18-E adsorbent and solid-phase analytical derivatization with N,O-bis(trimethylsilyl)trifluoroacetamide. Gas chromatography-mass spectrometric characteristics were determined to identify compounds in the St. John's wort aqueous extract. The results of the identification of compounds satisfactory agree with the HPLC-DAD data obtained using standard substances, allowing a conclusion that the solid-phase analytical derivatization of phenolic compounds is comparable in analytical capabilities to derivatization in solution., Author(s): Z. A. Temerdashev [sup.1] , E. A. Vinitskaya [sup.1] , V. V. Korobkova [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Department of Chemistry and High Technology, Kuban [...]

The work is dedicated to the determination of polyaromatic hydrocarbons (PAHs) in soils and bottom sediments by gas chromatography-mass spectrometry using sample preparation with the extraction of analytes into a solvent and the simultaneous purification of the extracts by dispersive solid-phase extraction (QuEChERS). The test samples were samples of sand, loamy soil, and silty bottom sediments, and 20 PAHs were used as analytes. To minimize matrix effects, sample preparation conditions were optimized, and the effect of ultrasound on the extraction of analytes was studied. The recovery of PAHs from sand and silty bottom sediments varied within 80-105%, and from loamy soils, it was 60-99%. PAHs were identified and quantified by gas chromatography-mass spectrometry with detection in the selected ion monitoring mode. The QuEChERS sample preparation contributes to a prolonged life of the equipment while maintaining the sensitivity of analyte detection. The procedure was tested using a soil sample collected at the territory of the Taman Bulk Cargo Terminal (Russia)., Author(s): Z. A. Temerdashev [sup.1], T. N. Musorina [sup.1], S. K. Ovsepyan [sup.1], I. G. Korpakova [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Kuban State University, , 350040, [...]

Specific features of the choice of conditions for determining the sizes of silver nanoparticles in aqueous dispersions by single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) are discussed. It is shown that the limiting factors for determining the sizes of analyte nanoparticles are the degree of sample dilution and the dwell time under optimized operating conditions of the mass spectrometer. The reliable determination of the sizes of silver nanoparticles of 60 and 100 nm at the duration of an analysis of 60 and 180 s, respectively, was achieved at a concentration of 2-4 ng/mL. A possibility of predicting dwell time for nanoparticles of a known size is demonstrated. The determination of several average sizes of nanoparticles is shown on an example of a polydisperse mixture of silver nanoparticles with sizes of 60 and 100 nm at a 10 ms dwell time., Author(s): Z. A. Temerdashev [sup.1], O. A. Galitskaya [sup.1], M. A. Bol'shov [sup.2], K. A. Romanovskii [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Kuban State University, , 350040, [...]

The review systematizes data on various extraction techniques for sample preparation in the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental samples, provides a classification, and describes the capabilities of these techniques. The main versions and methods of solid-phase extraction (SPE) and liquid-liquid (LLE) extraction of structurally different PAHs from complex multicomponent systems are discussed. The variety of SPE and LLE methods, the peculiarities of their combinations with other methods, and the advantages and disadvantages of each sample preparation method are demonstrated. Chromatographic methods are preferred for detection after the solid-phase or liquid-liquid extraction of PAHs from environmental samples., Author(s): Z. A. Temerdashev [sup.1], T. N. Musorina [sup.1], T. A. Chervonnaya [sup.1], Zh. V. Arutyunyan [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Kuban State University, , 350040, [...]

We performed a chromatographic evaluation of the recoveries of native forms of the main isoflavonoids from different morphological parts of red clover (Trifolium pratense L.) into water-alcoholic extracts using various extraction methods. Water-alcoholic extracts from red clover, obtained by maceration, microwave, ultrasonic, subcritical, and pharmacopoeial methods, were analyzed. Formononetin (0.260 mg/g) and genistein (0.051 mg/g) were maximally extracted from inflorescences of red clover by maceration; bioch-anin A was extracted by subcritical extraction (0.340 mg/g), and daidzein was extracted by ultrasonic method (0.034 mg/g). The conditions for the HPLC determination of daidzein, genistein, formononetin, and biochanin A in water-alcoholic extracts from red clover were optimized. The concentrations of isoflavonoids in various morphological parts of red clover were determined. The maximum total amount of isoflavonoids (0.190 mg/g) was observed in the water-ethanol extract from inflorescences., Author(s): Z. A. Temerdashev [sup.1], T. K. Chubukina [sup.1], E. A. Vinitskaya [sup.1], M. V. Nagalevskii [sup.1], N. V. Kiseleva [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Kuban [...]

Based on the concentrations of metals and volatile compounds in red and white wine samples and using linear and general linear models, we performed a comparative analysis of their contributions to the formation of sensory properties, the consolidated characteristic of which is the average value of sensory estimates given by experts. The contribution of volatile compounds to the sensory estimates exceeded that of metals by more than two times for red wines and more than three times for white wines. For red wines, the contributions of metals and volatile compounds to the variability of sensory estimates are approximately equal, and in the case of white wines, the contribution of volatile compounds is much higher than the contribution of metals. The constructed models can be used to predict sensory estimates of red and white wines based on the concentrations of volatile compounds and metals., Author(s): A. A. Khalafyan [sup.1], Z. A. Temerdashev [sup.1], A. G. Abakumov [sup.1], Yu. F. Yakuba [sup.2] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Department of Chemistry and High [...]

We consider the ranking of dry white wines and their quality using sensory evaluation from the standpoint of multidimensional analysis when the test samples are presented as points of a multidimensional space with coordinates corresponding to expert scores. The degree of preference between the wine samples is expressed in terms of the similarity of sensory estimates, evaluated by the geometric distance between them. In addition to ranking wines, this approach allowed us to study their cluster structure and reveal three groups of homogeneous wines based on the results of a set of expert scores given to them. A correlation the cluster structure of wines with their places in the ranked list is found. The consistency of wine ratings based on the proposed chemometric approach, arithmetic mean, and median scores is demonstrated. From the point of view of multivariate analysis, rating wines by the geometric distance is mathematically more reasonable, because it is built in accordance with the Euclidean metric, and the sum of coordinates of points, the calculation of the arithmetic mean is based on, does not correspond to any of the known metrics. Another advantage of the geometric approach is that the use of the arithmetic mean for the final assessment of the tasting results is justified at a great number of experts., Author(s): A. A. Khalafyan [sup.1], Z. A. Temerdashev [sup.1], A. G. Abakumov [sup.1], Yu. F. Yakuba [sup.2] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Department of Chemistry and High [...]

A possibility of using carbon sorbents for the extraction, preconcentration, and chromatographic determination of phenolic substances of plant origin is investigated. A method is proposed for the preconcentration of biologically active substances from extracts of medicinal plants with carbon sorbents followed by the desorption of analytes with organic solvents at elevated temperature and pressure. Some sorption characteristics of carbon materials Supelclean ENVI-Carb and HyperSep Hypercarb in relation to phenolcarboxylic acids and flavonoids isolated from aqueous extracts of St. John's Wort Hypericum perforatum L. are studied. The conditions of the sorption and desorption of analytes of various classes are optimized. A possibility of using carbon sorbents for the extraction and preconcentration of phenolic substances from aqueous extracts of various medicinal plants is shown using an examples of creeping thyme Thymus serpyllum L. and sage Salvia officinalis L., Author(s): Z. A. Temerdashev [sup.1], E. A. Vinitskaya [sup.1], V. V. Milevskaya [sup.1], M. A. Statkus [sup.2] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Kuban State University, , 350040, [...]

We studied the component composition of the essential oil of garden sage (Salvia officinalis L.), obtained by various extraction methods. Essential oils were obtained by hydrodistillation and subcritical CO.sub.2 extraction, supercritical fluid extraction, and subcritical extraction with solid-phase and liquid-liquid preconcentration. The components were identified by comparing the recorded mass spectra with the spectra of individual compounds and the data of the NIST07 and WILEY8 data bases. For all extraction methods, the major essential oil components were 1,8-cineole, camphor, [alpha]-thujone, [beta]-thujone, borneol, 4-terpineol, [beta]-caryophyllene, [beta]-caryophyllene oxide, and viridiflorol. The concentration of analytes in the extracts varied depending on the extraction method. In total, 104 components were identified in the extracts, of which 30 were extracted by hydrodistillation, 32 by subcritical CO.sub.2 extraction, 14 by supercritical fluid extraction, 46 and 62 by subcritical extraction with solid-phase and liquid-liquid extraction into the organic phase. An increase in the number of components in more stringent extraction methods as compared to hydrodistillation showed that, in the extracts, a deeper decomposition of macrocomponents might take place, except for camphor., Author(s): Z. A. Temerdashev [sup.1], V. V. Milevskaya [sup.1], L. P. Ryabokon' [sup.1], N. N. Latin [sup.2], N. V. Kiseleva [sup.1], M. V. Nagalevskii [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 [...]

The problems and advantages of chromatographic methods for the determination of polycyclic aromatic hydrocarbons (PAHs) in model and real samples of black soil (chernozem), sand, and bottom sediments of the Sea of Azov and the Kurchansky estuary are discussed. We substantiated and implemented sample preparation for analysis using dispersion liquid-liquid microextraction. PAH concentrations in soils of various types and bottom sediments were determined by gas chromatography-mass spectrometry. The specific features of sample preparation of soil and bottom sediments are studied aimed at achieving the maximum recovery of PAHs into the organic phase; the composition of the extraction system and the conditions for the extraction of analytes are optimized; the optimal sample weight is selected. We proposed a gas chromatographic system with mass spectrometric detection (GC-MS) for determining 20 PAHs in soil (bottom sediments). The limits of quantification for the studied PAHs in soils and bottom sediments were 0.2-0.5 [micro]g/kg. The optimized procedure for the GC-MS determination of PAHs was tested on real samples of bottom sediments of the Temryuk Bay of the Sea of Azov., Author(s): Z. A. Temerdashev [sup.1], T. N. Musorina [sup.1], T. A. Chervonnaya [sup.1] Author Affiliations: (1) grid.26083.3f, 0000 0000 9000 3133, Department of Chemistry and High Technology, Kuban State University, [...]

The current status and problems of the determination of polycyclic aromatic hydrocarbons (PAHs) in surface waters are discussed. Sixteen unsubstituted PAHs, which are priority pollutants of aquatic ecosystems, are selected as analytes. Gas chromatography-mass spectrometry (GC-MS) ensures the identification of the majority of pollutants using an integrated spectral library and their determation at a level below the maximum permissible concentration (MPC). The conditions for the simultaneous determination of 16 unsubstituted PAHs by GC-MS with detection in the selected ion monitoring mode are optimized. PAHs were extracted from a 1-L water sample by ultrasound-assisted liquid-liquid extraction. The main performance characteristics of the procedure were estimated. The lower limit of the analytical range was from 0.5 ng/L (benzo(a)pyrene) to 50 ng/L (naphthalene); the upper limit of the analytical range was 250 ng/L for all PAHs. The procedure was tested in model systems and real samples., Author(s): Z. A. Temerdashev [sup.1], T. N. Musorina [sup.1], N. V. Kiseleva [sup.1], B. D. Eletskii [sup.2], T. A. Chervonnaya [sup.1] Author Affiliations: (Aff1) 0000 0000 9000 3133, grid.26083.3f, Department [...]

The efficiency of extraction of biologically active substances from common St. John's wort (Hypericum perforatum L.) under varied conditions was compared in order to optimize a sample preparation procedure. The extraction with water and water-alcohol solutions under static conditions and with stirring was examined; the effect of ultrasonic treatment and extraction with water and water-alcohol mixtures under dynamic conditions at elevated temperature and pressure and the extraction with supercritical carbon dioxide were studied. It was established that, in the extraction of biologically active substances from plant materials, the chemical affinity of an extractant the extracted component is of primary importance; an increase in the pressure under dynamic conditions is the second factor in importance, which increases the efficiency of extraction. Keywords: extraction, biologically active substances, medicinal herbs, common St. John's wort (Hypericum perforatum L.), hyperforin, flavonoids DOI: 10.1134/S1061934815120126, Medicinal plants and preparations on their basis have been widely used in medicine for a long time. Quality assessment procedures for medicinal plant raw materials are regulated (for example, see [...]

The properties of a Diasorb-130-IDK sorbent based on silica gel with a grain size of about 6 pm were studied in order to choose conditions for the separation of the rare-earth elements from the samples of natural wine and their subsequent determination by inductively coupled plasma mass spectrometry. The possibility of the quantitative separation of the elements with the use of an ultrasonic flow suspension column was demonstrated. The results were compared with data obtained with the use of other sample preparation methods. A procedure was proposed for the determination of the rare-earth elements and yttrium in the samples of wines. Keywords: suspension columns, ultrasound, rare-earth metals, wine DOI: 10.1134/S1061934815120059, Sorption methods for the preconcentration of analytes are widely used in analytical chemistry. Various grainy sorbents are commonly used in the form of packed beds retained in a column or [...]

Byline: Z. A. Temerdashev (1), T. B. Pochinok (1) Abstract: The requirements for the minimum content and level of training to give the supplemental Expert in Environmental Safety qualification to graduates of classical universities specializing in chemistry (specialty no. 011000) were developed. An educational program is proposed. The program can be used as an efficient supplement of the professional training of students specializing in analytical chemistry it allows the level of stating analytical problems and interpreting analytical results (for environmental samples) to be improved. The program has been approved by the Ministry of Education of the Russian Federation. It has already been launched at the Chemical Faculty of the Kuban' State University. Author Affiliation: (1) Kuban' State University, ul. Stavropol'skaya 149, Krasnodar, Krasnodar, 350040, Russia Article History: Registration Date: 11/10/2004

Byline: M. Yu. Burylin (1), Z. A. Temerdashev (1), V. P. Polishchuchenko (1) Abstract: A procedure was developed for the preconcentration of arsine on palladium-containing adsorbents followed by the determination of arsenic by electrothermal atomic absorption spectrometry. Aqueous suspensions of the adsorbent were placed in a graphite furnace at the determination step. The selection of the adsorbent was substantiated adsorption properties of palladium-containing adsorbents were studied to validate their modifying properties. The absolute and concentration limits of detection for arsenic were 28 pg and 12 ng/L, respectively (sample volume of 100 mL). Author Affiliation: (1) Department of Chemistry, Kuban State University, ul. Stavropol'skaya 149, Krasnodar, 350040, Russia Article History: Registration Date: 13/10/2004

Byline: V. V. Perekotii (1), Z. A. Temerdashev (1), T. G. Tsyupko (1), E. A. Palenaya (1) Abstract: The electrochemical behavior of Crystal Violet (CV) on the surface of a glassy carbon electrode in potassium chloride, nitrate, and iodide supporting electrolytes was studied using stripping voltammetry. It was demonstrated that an electroactive complex of CV with iodine was adsorbed on the electrode in a KI solution. This property can be used for determining iodide by adsorption--stripping voltammetry. Author Affiliation: (1) Department of Chemistry, Kuban State University, ul. Stavropol'skaya 149, Krasnodar, 350040, Russia Article History: Registration Date: 13/10/2004

Byline: Z. A. Temerdashev (1), N. V. Kiseleva (1), A. V. Udalov (1), R. A. Klishchenko (1) Author Affiliation: (1) Kuban State University, ul. Stavropol'skaya 149, Krasnodar, 350040, Russia Article History: Registration Date: 11/10/2004

Byline: E. Sh. Alieva (1), T. G. Tsyupko (1), Z. A. Temerdashev (1) Author Affiliation: (1) Kuban State University, Stavropol'skaya ul. 149, Krasnodar, 350040, Russia Article History: Registration Date: 11/10/2004