Search

The review considers the main trends in actively developing methods of solid-phase and liquid-liquid microextraction for the extraction, purification, and preconcentration of analytes from medicinal plants and plant materials, the use of new extractants and approaches to the preparation of samples of plant origin, and their compatibility with mass-spectrometric detection. Particular attention is paid to the analytical capabilities, advantages, and limitations of each of the approaches to extracting analytes from plant materials for the subsequent analysis of the obtained extracts by chromatography-mass spectrometry., Author(s): E. A. Bessonova [sup.1] , D. A. Karpitskii [sup.1] , L. A. Kartsova [sup.1] Author Affiliations: (1) https://ror.org/023znxa73, grid.15447.33, 0000 0001 2289 6897, St. Petersburg State University, , 198504, [...]

Handheld Raman spectroscopy offers a rapid and mobile technique for determining drugs nondestructively. The technique offers further advantage for analyzing drug products (DPs) thanks to its ability to measure samples through packaging, thus preserving evidence integrity and continuity. This research evaluated the use of handheld Fourier transform (FT)-Raman spectroscopy for characterization of street DPs (n = 254) of diverse formulations. Raman spectra of DPs inside their packaging were collected and matched against the instrumental in-built library, and then exported to Matlab 2020a for offline spectral interpretation. Reference analysis was confirmed using gas chromatography-mass spectrometry (GC-MS) and infrared (IR) spectroscopy. The main drugs present were 1,3-trifluoro-methylphenylpiperazine, cocaine, ketamine, 3,4-methylenedioxymethamfetamine, mephedrone, and 1-benzylpiprerazine. The main impurities present in DPs were benzocaine, caffeine, and lactose. The impurities affected the Raman signature (enhanced or inhibited) of DPs, enabling profiling of DPs and visualizing patterns among different products. These latter patterns were featured in the similarities highlighted by the correlation coefficient values between different DPs, and by adjacent clusters of different DPs envisaged in the principal component analysis scores plot., Crime and violent behaviors have increased because of the widespread use of illicit drugs in contemporary societies. Amsterdam (1027.7), London (701.1), and Copenhagen (780 mg/1000 p/day) had the highest weekend [...]

In the qualitative analysis of complex mixtures of unknown composition, a promising direction for increasing the reliability of the identification of substances is the joint use of several simultaneously determined analytical parameters. A combination of chromatographic methods with FTIR spectroscopy, mass spectrometry, or other methods is used. In solving complex analytical problems of industrial nature, it is economically expedient to use only chromatographic methods. In analyzing complex multicomponent mixtures with a high density of peaks in the chromatogram, the precision of the determination of retention time determines the reliability of the identification of substances and of the result of analysis, using identification both directly by the absolute retention time and by relative parameters derived from it (relative retention times, retention indices). The standard deviation of a measurement of the chromatographic retention time is a measure of precision. Experimental chromatographic retention times were obtained for analyzing a mixture by the following scheme: initial isotherm, temperature programming, final isotherm. A sharp increase (by one order of magnitude) in the numerical value of the standard deviation was noted at the step of temperature programming. A regression equation was obtained linking the point estimate of the standard deviation of the retention time and column temperature. The performance characteristic of the regression equation is obtained as a function that enables calculating the total standard uncertainty in the estimate of the standard deviation of the chromatographic retention time. The results can be used to refine chromatographic retention time and indices that ensure the reliable identification of substances., Author(s): V. I. Abdrakhmanov [sup.1], S. A. Dobrotin [sup.2], O. N. Kosyreva [sup.2], V. I. Logutov [sup.3] Author Affiliations: (1) Areal Medical Company, , 129329, Moscow, Russia (2) Department of [...]

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, [...]

A method of chromatography-mass spectrometry is used to study the impurity composition of arsine synthesized by the reaction of arsenic chloride with sodium borohydride. Capillary adsorption columns with adsorbents modified silica and polytrimethylsilylpropine is used for the separation of impurities. Impurities are identified by comparing their mass spectra with the NIST database, published data, as well as by reconstructing their structures from fragment ions. Impurities of permanent gases; saturated and unsaturated hydrocarbons C.sub.1-C.sub.6; chlorinated, oxygenated, and aromatic hydrocarbons; volatile inorganic hydrides; and alkyl derivatives of arsine, trimethyl fluorosilane, carbon sulfur dioxide, and dimethyl sulfide are identified in arsine. Mass spectra of C.sub.2H.sub.3AsH.sub.2, CH.sub.3AsHC.sub.2H.sub.5, and C.sub.2H.sub.5As.sub.2H.sub.3 impurities are obtained for the first time., Author(s): A. Yu. Sozin [sup.1], O. Yu. Chernova [sup.1], T. G. Sorochkina [sup.1], A. P. Kotkov [sup.1] [sup.2], N. D. Grishnova [sup.1] [sup.2], D. M. Polezhaev [sup.2], G. V. Pushkarev [...]

Headspace solid-phase microextraction (HS-SPME) was used to quantify the concentrations of N-nitrosodimethylamine, N-nitrosodiethylamine (NDEA), N-nitrosopiperazine (NPIP) and N-nitrosodibutylamine in five white wines produced in different countries worldwide. A gas chromatograph coupled to a mass spectrometer (GC-MS) was used for detection and quantification of N-nitrosoamines (NAms). Two types of NAms were found in the wines studied: N-nitrosodimethylamine and N-nitrosodibutilamine. The concentrations of the NAms found were innocuous in all the cases studied. The effects of the microextraction parameters (equilibrium temperature, extraction temperature, ionic strength and extraction time) on the GC-MS signal obtained from the NAms were evaluated. The HS-SPME-GC-MS method was validated by calculating the linearity, repeatability, limits of detection and quantification. Neither NDEA nor NPIP was detected in any of the samples analyzed. The standard additions method was applied for the quantitation of the found NAms using internal standards., Author(s): Guillermo Gonzalez-Alatorre [sup.1], Fernando Jonathan Lona-Ramírez [sup.2], Ma. Cristina Irma Perez-Perez [sup.3], Rosalba Patiño-Herrera [sup.1], Christian Oliver Diaz-Ovalle [sup.4] Author Affiliations: (1) grid.466827.9, 0000 0004 0369 1695, Tecnológico Nacional [...]

A review of scientific publications covering the acquisition and use of big data in modern analytical chemistry is presented. Such data are characterized by considerable volumes, flows, and variety. Their generation and manipulations with them accompany the analysis of biosamples and samples of other origin by chromatography and mass spectrometry. Big data obtained by these techniques ensure multianalyte sample analysis, though the characteristics of the detection, identification, and quantification are satisfactory not for all analytes. The application of simple analytical systems can also be accompanied by the accumulation of big data volumes. A huge body of information is contained in big chemical databases, the use of which is necessary in non-target analysis. The selection of candidates for identification takes into account the prevalence (citation rate) of chemicals; identification includes the use of reference mass spectral libraries. Methods of data processing, analysis, and presentation (statistics, chemometrics) evolve with the growth of the volume of information. Technical characteristics of computers and their networks are improved at advancing rates, creating a potential for the development of methods of data analysis and opening new possibilities for interlaboratory cooperation., Author(s): B. L. Milman [sup.1], I. K. Zhurkovich [sup.2] Author Affiliations: (1) grid.465311.4, 0000 0004 0482 8489, Institute of Experimental Medicine, , 197376, St. Petersburg, Russia (2) Institute of Toxicology, [...]

Background In pediatric chronic kidney disease (pCKD), traditional factors (proteinuria, etiology, and race) do not fully explain disease progression. The levels of methylated arginine derivatives (MADs: asymmetric and symmetric dimethylarginine, respectively) rise in CKD and increase with CKD progression. The impact of MADs on glomerular filtration rate (GFR) decline has not been examined in pCKD. The aim of this study was to examine the additive impact of baseline (BL) levels of MADs on directly measured GFR (mGFR) decline per year (ml/min/1.73 m.sup.2/year) for a period of up to 4 years. Methods Plasma and data, including mGFR by plasma iohexol clearance, were provided by the prospective, observational Chronic Kidney Disease in Children study. BL MADs were analyzed by high-performance liquid chromatography-tandem mass spectrometry. Results For 352 pCKD subjects, the median [interquartile range] BL mGFR was 45 [35, 57] ml/min/1.73 m.sup.2. The levels of BL MADs were inversely related to the initial mGFR and its decline over time (p < 0.0005) but not to the rate of decline. Covariates, non-glomerulopathy and Tanner stage of [greater than or equal to] 3 demonstrated weaker relationships between BL levels and beginning mGFR (p = 0.004 and p = 0.002, respectively). Conclusions In pCKD, higher concentrations of BL MADs were inversely related to BL mGFR. MADs did not affect the CKD progression rate. Quantification of this relationship is novel to the pCKD literature., Author(s): Ellen R. Brooks [sup.1] [sup.2] , Shannon Haymond [sup.1] [sup.3] , Alfred Rademaker [sup.1] [sup.4] , Christopher Pierce [sup.5] , Irene Helenowski [sup.1] [sup.4] , Rod Passman [sup.1] [sup.6] [...]

Several sport nutrition products and doping drugs sold in the period from 2014 to 2016 were studied using gas and liquid chromatography coupled with mass-spectrometry. In the study, WADA-banned substances were detected in the composition of pre-workout supplements, fat burners, and prohormones. A series of selective androgen receptor modulators and peptide doping drugs were also studied. It was shown that, in some cases, preparations can be adulterated. Keywords: doping, sport nutrition, SARM, peptide doping, ultra-high performance liquid chromatographytandem mass spectrometry, high-resolution mass spectrometry, gas chromatography-mass spectrometry DOI: 10.1134/S1061934817110090, In recent years, the promotion of sport and healthy lifestyles is conducted as part of governmental programs. In addition to an increase in the indices of population engagement in various [...]

Several sport nutrition products and doping drugs sold in the period from 2014 to 2016 were studied using gas and liquid chromatography coupled with mass-spectrometry. In the study, WADA-banned substances were detected in the composition of pre-workout supplements, fat burners, and prohormones. A series of selective androgen receptor modulators and peptide doping drugs were also studied. It was shown that, in some cases, preparations can be adulterated. Keywords: doping, sport nutrition, SARM, peptide doping, ultra-high performance liquid chromatographytandem mass spectrometry, high-resolution mass spectrometry, gas chromatography-mass spectrometry DOI:10.1134/S1061934817110090, In recent years, the promotion of sport and healthy lifestyles is conducted as part of governmental programs. In addition to an increase in the indices of population engagement in various [...]

An archaeological artifact, representing a compound piece of the Bronze Age, the outer surface of which is encrusted with seeds, has been investigated. The chemical composition of the organic binder was determined by gas chromatography and mass spectrometry; X-ray fluorescence analysis was used to determine the nature of the inorganic base of the artifact. Keywords: archaeological artifact, fatty acids, gas chromatography, mass spectrometry, X-ray fluorescence analysis, Recently, various physicochemical methods have been widely used to identify the nature of the individual components that make up archaeological finds: IR spectroscopy, atomic spectroscopy, mass spectrometry, HPLC, and gas [...]

Mixtures of 13 normal and modified nucleosides in a 70 mM phosphate buffer solution (pH 6.7) supplemented with 100 mM of sodium dodecyl sulfate were separated by micellar electrokinetic chromatography in 25 min. Electrophoretic profiles of urine are obtained; it is demonstrated that 1-methylinosine and 1-methylguanosine nucleosides can be used as markers of precancerous states (mastopathy) and benign tumors (fibroadenoma). Keywords: tumor markers, diagnosis of cancer, nucleosides, urine, micellar electrokinetic chromatography, Determination of tumor markers in biological fluids (blood serum, urine) is an important component of the diagnostic complex in oncology. The term 'tumor markers' denotes compounds found in biological fluids [...]

Using the IONCHROM software, we performed modeling of a new chromatographic system on an example of an ion chromatograph from METROHM. To determine all necessary parameters, we had to construct a dynamic map of this system, by which the conditions of the required separation were found in different pH and concentration ranges, after which three or four experiments with the chosen eluents were sufficient. The model corrected with the the found parameters was used to predict the behavior of the system and, in particular, to optimize the analysis. Keywords: ion chromatography, mathematical modeling, optimization of the analysis of anions, In the organization of chromatographic analysis, the problem of the design of experiment and of the interpretation of its results is solved using the available experience and theoretical knowledge, which [...]

Optimal conditions are found for the simultaneous determination of tranexamic acid, ampasse, and ethylmethylhydroxypyridine succinate by reversed-phase HPLC. As is shown, under these conditions the reversed-phase mechanism of retention prevails and the analytes occur mainly in a specific ionic state with an optimal retention time. The possibility of using chromatography columns from various manufacturers is estimated. The method was used to analyze title materials and impurities in drug formulations. Keywords: HPLC, API analysis, tranexamic acid, ethylmethylhydroxypyridine succinate, ampasse DOI: 10.1134/S1061934814020051, Tranexamic acid, trans-4-(aminomethyl)-cyclohexane carboxylic acid, T, 2-ethyl-6-methyl-3-hydroxypyridine succinate, M, and ampasse, 5-hydroxy-3-carboxypyridin-L-glutamic acid, A, possess a wide variety of pharmacological effects. They demonstrate antioxidant, anti-hypoxic, nootropic, and anti-inflammatory activity; tranexamic [...]

The optimal conditions for the separation of pesticides of the following classes: phenoxy carboxylic acids, sim-triazines, triazinones, chloroacetamides, urea derivatives, neonicotinoids, carbamates, triazoles, imidazoles, benzimidazoles, and phosphorus organic compounds by micellar electrokinetic chromatography have been selected. A method for determining 27 polar pesticides in soil using QuEChERS sample preparation has been developed. The recovery of pesticides was from 31 to 104%. The lower limits of the found pesticide concentrations in soil taking into account preconcentration were 0.01-0.4 mg/kg. The relative standard deviation of the results of analysis does not exceed 10%. Keywords: micellar electrokinetic chromatography, polar pesticides, QuEChERS, soil DOI: 10.1134/S1061934814010055, Polar pesticides are often used for the control of pests, insects, rodents, and plant diseases. As a consequence, residue amounts of these chemical substances are widespread in environmental objects. The [...]

New sample preparation technologies are being proposed all of the time. Many are novel and interesting but will never have a big impact on the sample preparation scene. Some, however, [...]

Conditions of the simultaneous isolation of various types of Zolpidem metabolites from samples of real urine by solid-phase extraction have been optimized. Various derivatives of Zolpidem hydroxy- and carboxy-metabolites were obtained; their mass-spectral and gas-chromatographic characteristics have been studied. The results ensure the reliable identification of Zolpidem metabolites by gas chromatography--mass spectrometry for chemical toxicological and forensic investigations. Keywords: Zolpidem, metabolism, solid-phase extraction, gas chromatography, mass spectrometric detection DOI:10.1134/S1061934813080066, INTRODUCTION Zolpidem (synonym for SL-80.0750), chemical name N,N,6-trimethyl-2-(4-methylphenyl)imidazo[1,2-a]pyridine-3-acetamide, is produced by pharmaceutical companies as tartrate under the following trade names: Ivadal, Ambien, Bikalm, Cedrol, Dalparan, Niotal, Stilnoct, and Stilnox. Zolpidem [...]

ARTICLE INFO Keywords: Pinus wollichiona Essential oil GC/CC--MS Antiproliferative activity Radical scavenging activity ABSTRACT Purpose: To evaluate the in vitro anti-proliferative and radical scavenging properties of the essential oil and [...]

It is found that carbon nanotubes (CNTs) obtained by the catalytic pyrolysis of ethanol vapor with Ni-, Co-, and Fe catalysts vary in their ability to oxidative modification and, finally, in adsorption capacity, dispersion, and the texture of the synthesized powders. The adsorption capacity of the modified CNTs varies in the order Ni > Co > Fe. The material obtained with a Ni catalyst has good bulk and hydrodynamic properties, which is essential for use in chromatographic columns. Using a Fe catalyst, a loose, cotton wool-like product was obtained that is unsuitable for column chromatography, and with a Co catalyst, a material with intermediate properties was synthesized. Differences in the physicochemical properties of CNTs are related to the morphology of the products. Keywords: multiwalled carbon nanotubes, synthesis catalysts, adsorption of metal ions, atomic spectroscopy. DOI: 10.1134/S1061934812050061, Studies have shown that CNTs have perspectives for analytical applications: for the modification of the electrodes in electroanalysis, the manufacture of bio-, piezo-, and gas sensors, and as adsorbents for [...]