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A method for quantitation of exogenous cis fatty acids in the presence of exogenous cis and trans fatty acids that does not require time-consuming and tedious chromatographic separation is described. In it, we use an inhibitor that blocks Elovl6, an enzyme involved in fatty acid synthesis in vivo. Samples prepared in the absence or presence of the inhibitor are sequentially analyzed by liquid chromatography with mass spectrometric detection. The developed method is used for analyzing endogenous cis fatty acids synthesized in cancer cells.

This work is aimed at obtaining mixed cluster ions of amino acids with copper salts using soft ionization methods. We have shown that amino acid molecules are capable of forming aggregates stabilized by d-metals. In particular, such clusters can form in the presence of silver salts. In the present work, it is revealed that the largest cluster ions can be obtained using the electrospray ionization method. It is found that, upon ionization of amino acids (leucine, alanine, proline, tyrosine, and tryptophan) in the presence of copper salts, cluster associates with a mass of up to 1500 Da are formed. It is also found that the formation of cluster ions strongly depends on the nature of the amino acid and polarity of the charge in the cluster.

A comparative study of adsorption of isomeric alkylbenzenes, alkylphenols, and alkanes on carbon sorbents from a gas and a liquid phase using an extended variant of molecular statistics calculations is carried out. In simulation, conformational non-rigidity of molecules is taken into account. This method is shown to satisfactorily estimate proportions between the adsorption characteristics for isomers of hydrocarbons adsorbed on graphitized thermal carbon black from a gas phase. In the case of adsorption from a liquid phase on porous graphitized carbon, additionally, the effect of a solvent and polarizability of the sorbent surface by charged sites of a sorbate molecule are considered. It is demonstrated that, for correct prediction of the ratio between the Henry constants for adsorption of isomers of alkylphenols and alkylbenzenes from solutions, it is necessary to consider both these factors.

The identification features of symmetric and nonsymmetric diaryl telluroxides via chromatography/mass spectrometry with electrospray ionization (HPLC/MS-ESI) are studied in the present work. Diaryl telluroxides exposed to ESI are shown to give rise to the formation of dimer ions and associate ions with the mobile phase components. Moreover, the influence of analyte concentration in the solution and the injection volume is found to impact the chromatography/mass spectrometry data.

Investigation of the physical chemistry of adsorption by carbon sorbents is a very important task from both theoretical and practical points of view. The thermodynamics of adsorption is affected by defects on the sorbent surface, including oxygen-containing functional groups. In this work, adsorption of a series of aromatic and aliphatic amines and nitriles by the surface of graphitized thermal carbon black is simulated using the Monte Carlo method. The results of calculations are compared to the experimental data. The cases of isolated and paired arrangement of functional groups are considered, and regularities of interaction between different classes of nitrogen-containing compounds and such defects are revealed. On the basis of comparison with the experimental data, assumptions about the presence and distribution of hydroxyls on the surface of graphitized thermal carbon black are made.

A complex analysis of the crumbed rubber produced by the explosive circulation method has been performed by the methods of AFM, X-ray diffraction, gas chromatography, mass spectrometry, and gel-permeation chromatography (GPC). The results of the small- and wide-angle X-ray diffraction study have revealed an amorphous structure of the samples without supramolecular ordering at a distance scale of ~1–40 nm. Globular formations of a size of 5–20 nm on the crumb surface combined into clusters of various shapes and sizes in the range 100–1000 nm have been found by means of the AFM method. Individual nanoglobules and small and large clusters of these nanoglobules appeared to be randomly covering the surface of the examined samples. It has been established that the nanoglobules partially consist of saturated and unsaturated hydrocarbons of low-molecular weight, which belonging to classes of linear, cyclic, and aromatic compounds. Most of the nanoglobules are represented by oligomeric products having 3–5 units, as well as compounds of higher molecular weight. All of the above compounds provide better adhesion of the regenerate to different matrices than that produced by other methods. The composition of the nanoscaled globules includes secondary products of reactions of low-molecular hydrocarbons formed from rubber tires at their explosive circulation grinding.

This work studies regularities of the aldol condensation reaction between 3,4-dimethoxybenzal-dehyde and 4-bromo-acetophenone with formation of 1-(4-bromophenyl)-3-(3,4-dimethoxyphenyl)-2-propene-1-one catalyzed by di(4-methoxyphenyl)telluroxide. Conditions are found for separation of the reaction mixture components and catalyst using reverse phase high-performance liquid chromatography (RP HPLC) with mass-spectrometric detection by electrospray ionization (ESI). Special features of separation of reaction mixture components and mass spectrometric analysis are discussed.

Ionization of model compounds is studied using the example of lead halides with the method of mass spectrometry with surface-activated laser desorption/ionization (SALDI) on surfaces of different types. Clusters of lead halides are determined in a wide range of masses, up to 2 kDa. The dependence of ionization on the concentration, support type, and method of application of model samples is shown. The surface of a fragment of the combustion chamber of a liquid rocket engine is studied using the method of SALDI mass spectrometry. Lead and oxides and chlorides thereof are detected on the surface of a combustion-chamber fragment. It is suggested that peeling of a nickel coating may be caused by the presence of lead clusters at the nickel-bronze interface.

Differences in the energetic and kinetic characteristics of the ionization of silver halides from different surfaces are found with the use of mass spectrometry. Ionization of silver-halide clusters from the surface of a standard target made of polished stainless steel (Bruker) is studied in comparison to AMg-6 and Ad-0 aluminum-alloy materials. It is found that, despite the lower specific ionization energy, a rough surface strongly hampers the evaporation and desorption and, hence, lowers the efficiency of sublimation and desorption of a substance. In addition, a rough surface is characterized by irregular surface distribution of energy and uneven heating, which also lowers the efficiency of ionization. The surface geometry is found to affect the thermodynamics and kinetics of the formation and fragmentation of ions. On rough surfaces, the formation energies of ions are higher by a factor of 1.5–2 compared to those on polished surfaces and the spectrum of ions and energy ranges of their existence are much broader.

This paper deals with some new arguments corroborating the absence of carbonyl moieties [1] in the chemical structure of hypercrosslinked polystyrenes in spite of the high intensity of the absorption band around 1700 cm−1 in their FTIR spectra. Three additional facts testify to the benefit of this conclusion. First is the appearance of the absorbance band at 1700 cm−1 in a computer-simulated IR spectrum of a rigid highly crosslinked model network that contains no C=O groups. Second, thermal degradation of the hypercrosslinked network with a formal 500% crosslinking density results in emergence in its mass-spectrum of benzene, alkylbenzenes and hydrogen chloride, only. Third, testing the above hypercrosslinked polystyrene as a stationary phase in a GC column shows the polymer to retain aliphatic hydrocarbons, alcohols and ketones largely by dispersion interactions, thus revealing no polar oxygen-containing groups on its surface.

The present study considers the transformation products of a number of compounds, including ones used as plasticizers and antifreezing agents for concrete, which can liberate ammonia during exploitation of the concrete products. We have analyzed plasticizers, antifreezing agents, and products of their transformation that are leached by water and/or organic solvents. The analysis procedure has been used for analysis of concrete samples from a real construction site.

Methods of thermogravimetric analysis, differential scanning calorimetry, and thermal desorption mass-spectrometry are used to study the processes of thermolysis of resveratrol on the surface of graphitized thermal carbon black (GTCB). The results obtained in thermolysis of pure resveratrol and resveratrol adsorbed on GTCB from diethyl ether are compared. The regions of maximum evolution of thermolysis products are determined; their compositions are identified; an increase in thermal stability of resveratrol supported on the surface of graphitized thermal carbon black is observed.

This paper discusses application of gas and liquid chromatography to studies of surface chemistry and various materials. Examples of studying adsorption processes from gas and liquid media with application of the chromatography technique are given. It is shown that the information on the structure of the material obtained using the chromatography technique allows predicting the regularities of chromatographic retention for molecules of different structures and various sorbents. The chromatography technique is frequently used in studies of nanomaterials and stable nanoparticles. It is shown that the chemical properties of surfaces modified by nanoparticles can be advantageously used in gas and liquid chromatography techniques. Much attention is given to molecular statistical calculations of adsorption on carbon sorbents in gas and liquid chromatography. The possibilities of the technique regarding prediction of retention of various sorbates and specification of structural parameters of molecules are demonstrated. Methodological and preparative aspects of a new area, micellar chromatography of nanoparticles, are considered. Options of liquid chromatography for separation, including preparative separation, identification, and classification, are shown.

The review explains the fundamentals of the methods of mass spectrometry with matrix assisted laser desorption/ionization (MALDI) and mass spectrometry with surface-assisted laser desorption/ionization (SALDI). Basics of these mass spectrometric techniques and regularities of applications of matrixes of various types are discussed. Examples of using the MALDI and SALDI techniques are presented for obtaining spectra of low-molecular compounds and compounds with a high molecular mass in connection with studies of corrosion inhibitors.

The influence of the essence of surface on mass spectrometry behavior of the medication, i.e., pentoxifylline, in the course of surface-enhanced laser desorption/ionization. For surfaces, we used a standard stainless-steel target for mass-spectrometric analysis using matrix-assisted laser desorption/ionization, AnchorChip, and the surfaces of pentoxifylline tablets. The influence of adding α-cyano-4-hydroxycinnamic acid to the matrix on the results of the mass-spectrometric analysis of pentoxifylline was studied.

Matrix-assisted and surface-enhanced laser desorption/ionization mass-spectrometry is carried out in order to investigate the surfaces of structural materials using marker substances. The method is shown to provide estimates of the surface heterogeneity and can be used for the quantitative comparison of the heterogeneity of different surfaces. In the domains where homogeneity is distorted, a larger amount of the marker substance is observed. Properly selected marker substances and the high sensitivity of mass-spectrometry make it possible to use the method for the express estimation of the surface heterogeneity.

Ad-0 and AMg-6 alloy surfaces are studied using matrix-enhanced laser desorption/ionization mass spectrometry. Inorganic salts, namely, nickel chloride and silver halides, which form cluster ions at the ionization, were taken as test molecules. Mass spectra revealed a principal difference between the desorption/ionization mechanisms depending on the surface kind and its prehistory. Qualitative and quantitative investigation of the mass spectra led to certain suppositions about the photoionization mechanisms of the cluster structures of inorganic nickel and silver salts. It is shown that, on the studied surfaces, parameters that characterize the surface chemistry can be estimated based on the mass spectra of the salts.

This study is devoted to the influence of the structures of hydrogen-bonded dimeric molecules on their adsorption at graphitized thermal carbon (GTC). The thermodynamic adsorption characteristics (TACs) of amino acid dimers and dimers of amino acids with acetic acid and formamide at GTC were determined. The results obtained for the adsorption of dimeric molecules at the carbon sorbent were compared with the calculated data for the molecules of the corresponding amino acids at GTC. The geometric parameters of dimeric molecules were varied to analyze the influence of the hydrogen bond lengths on the TACs of the compounds under study.

The thermodynamic characteristics of the adsorption of proline and its derivatives at graphitized thermal soot (GTS) were determined. It was found that the arrangement of the hydroxy groups in the amino acid molecule influences its adsorption at GTS. The thermodynamic characteristics of the adsorption of the stereoisomers of hydroxy- and dihydroxyproline at GTS were calculated. The influence of the internal rotation angles in the molecules of proline and its derivatives on their adsorption at GTS was studied.