Electron Spin Resonance Method Research Articles

Accurate identification of radicals by in-situ electron paramagnetic resonance in ultraviolet-based homogenous advanced oxidation processes

Accurate identification of radicals in advanced oxidation processes (AOPs) is important to study the mechanisms on radical production and subsequent oxidation-reduction reaction. The commonly applied radical quenching experiments cannot provide direct evidences on generation and evolution of radicals in AOPs, while electron paramagnetic resonance (EPR) is a cutting-edge technology to identify radicals based on spectral characteristics. However, the complexity of EPR spectrum brings uncertainty and inconsistency to radical identification and mechanism clarification. This work presented a comprehensive study on identification of radicals by in-situ EPR analysis in four typical UV-based homogenous AOPs, including UV/H2O2, UV/peroxodisulfate (and peroxymonosulfate), UV/peracetic acid and UV/IO4− systems. Radical formation mechanism was also clarified based on EPR results. A reliable EPR method using organic solvents was proposed to identify alkoxy and alkyl radicals (CH3C(=O)OO·, CH3C(=O)O· and ·CH3) in UV/PAA system. Two activation pathways for radical production were proposed in UV/IO4− system, in which the produced IO3·, IO4·, ·OH and hydrated electron were precisely detected. It is interesting that addition of specific organic solvents can effectively identify oxygen-center and carbon-center radicals. A key parameter in EPR spectrum for 5,5-dimethyl-1-pyrroline N-oxide (DMPO) spin adduct, AH, is ranked as: ·CH3 (23 G) >·OH (15 G) >IO3· (12.9 G) >O2·− (11 G) ≥·OOH (9–11 G) ≥IO4· (9–10 G) ≥SO4·− (9–10 G) >CH3C(=O)OO· (8.5 G) > CH3C(=O)O· (7.5 G). This study will give a systematic method on identification of radicals in AOPs, and shed light on the insightful understanding of radical production mechanism.

Impact of manganese sulfide (MnS) oxygenation-induced oxidization on aqueous organic contaminants: Insight into the role of the hydroxyl radical (HO·)

Manganese sulfide (MnS) has unique reactive abilities and can affect the fate and toxicity of contaminants in the natural environment, specifically sulfidic sediments that undergo biogeochemical changes due to natural and artificial processes. However, the effect of oxidization induced by the oxygenation of MnS on organic contaminants remains poorly understood. Herein, we revealed that the hydroxyl radical (HO·) was the dominant reactive oxidant for the rapid degradation of the assessed hydrophobic organic contaminants (including azo dye, nitroaromatic compounds, pesticide, and an endocrine disrupt chemical) during the oxygenation of MnS based on the competitive dynamic experiments, quenching experiments and electron spin resonance (ESR) methods. The removal rates of the assessed organic contaminants were significantly dependent on MnS dosage and co-solutes, including sediment humic acid, metal ions (Mn2+and Fe3+), and inorganic anions (PO43−and Cl−). HO· scavenging by sulfide and its oxidation products (e.g., elemental sulfur), rather than dissolved Mn2+, was responsible for the low utilization efficiency of HO· for the assessed contaminants. The contribution of the manganese oxide (MnO2) generated by the oxygenation of MnS to the examined degradation of contaminants could be neglected. Considered collectively, the reaction between H2O2 and MnO2 generated superoxide radicals (O2−·) which dominated the generation of HO· in an oxic MnS suspension. The results suggest that the impact of oxidization induced by the oxygenation of MnS on environmental contaminants should be of concern in both natural and engineered systems.

Microscopic Structures, Dynamics, and Spin Configuration of the Charge Carriers in Organic Photovoltaic Solar Cells Studied by Advanced Time-Resolved Spectroscopic Methods.

Organic photovoltaics (OPVs) are promising solutions for renewable energy and sustainable technologies and have attracted much attention in recent years. Two types of organic semiconductors are used as donor materials to fabricate OPV cells. One type is a photoconductive polymer, and the other type is a small-molecule-based compound. The discovery of a bulk-heterojunction (BHJ) structure using a mixture of p- and n-type organic semiconductors has dramatically increased the power conversion efficiency (PCE) of OPV cells. In this feature article, we review our recent studies on organic BHJ thin films and OPVs by using advanced time-resolved spectroscopic techniques. Two topics regarding the microscopic behaviors of the charge carriers are discussed. The first topic is focused on how to quantify the local mobility of the charge carriers. Here, we discuss charge carrier dynamics in diketopyrrolopyrrole-linked tetrabenzoporphyrin (DPP-BP) BHJ thin films studied by time-resolved terahertz spectroscopy on a subpicosecond to several tens of picoseconds time scale and by transient photocurrent measurements on a microsecond time scale. The second topic concerns the spin configuration and interaction of the electron and hole of the polaron pairs in polymer-based BHJ thin films and OPV cells studied by the time-resolved electron paramagnetic resonance method, time-resolved simultaneous optical and electrical detection, and measurement of the magnetoconductance effect.

Electron Paramagnetic Resonance: Study of the Regulatory Mechanisms of Light Phases of Photosynthesis in Plants

The electron paramagnetic resonance (EPR) method is widely used in the biophysics of photosynthesis, because it serves as an effective tool for exploring the processes of electron and proton transport in various photosynthetic systems. This study on the regulation of electron transport in chloroplasts was performed with the direct participation of the authors using the EPR method. The possibilities of the EPR method to study the kinetics of electron transport in chloroplasts of higher plants in situ (leaves of higher plants) at room temperature were shown, and the EPR spectra of chloroplasts at cryogenic temperatures were considered. The latter is of particular importance for substantiating the “kinetic” method of pH measurement inside thylakoids, which was used.

Controlled release starch-lipid implant for the therapy of severe malaria

Parenteral depot systems can provide a constant release of drugs over a few days to months. Poly-(lactic acid) (PLA) and Poly-(lactide-co-glycolide) (PLGA) are the most commonly used polymers in the production of these systems. Finding alternatives to these polymers is of great importance to avoid certain drawbacks of these polymers (e.g. microacidity) and to increase the selection possibilities. In this study, different types of starch in combination with glycerol monostearate (GMS) were developed and investigated for their physicochemical properties and release characteristics. The noninvasive method of electron paramagnetic resonance (EPR) was used to study the release kinetics and mechanisms of nitroxide model drugs. The studies demonstrated the general suitability of the system composed of high amylose starch and GMS to form a controlled release system. For further characterization of the prepared system, formulations with different proportions of starch and GMS, loaded with the antimalarial agents artesunate or artemether were prepared. The implants were characterized with X-ray powder diffraction (XRPD) and texture analysis. The in vitro release studies demonstrated the sustained release of artemether over 6 days from a starch-based implant which matches desired kinetic for the treatment of severe malaria. In summary, a starch-based implant with appropriate mechanical properties was produced that can be a potential candidate for the treatment of severe malaria.

Diamonds from low-grade kimberlite

Based on exploration and sampling work on the Siberian
 platform (SP) the uneven diamond content of
 various diatremes was established. During the exploration
 apart from the pipes with high or medium content
 of a useful component also the diatremes with low to
 very low diamond content were discovered. To obtain
 representative data the diatremes of two kimberlite fields
 of the Central Siberian (CS) and six kimberlite fields of
 the Lena-Anabar (LA) diamondiferous sub-provinces
 (DSP) were studied. A comprehensive study of diamonds
 from low-grade pipes of the Alakit-Markhinsky and
 Daldynskoye kimberlite fields of CSDSP was carried out.
 16 kimberlite bodies from six kimberlite fields from the
 LADSP were studied. Geology and mineral-petrographic
 composition of kimberlites, crystal-morphological and
 physical properties of diamonds from certain prospective
 areas were investigated. In addition to classifying
 diamonds into specific varieties according to Yu. L. Orlov
 (1984), for many crystals, we examined impurity
 centers, the ratio of the concentration of optically active
 defects, spectra of absorption of diamonds IR and UV
 for the visible regions. For many grains we determined
 the isotopic composition of carbon; carried out analyses
 using the electron paramagnetic resonance (EPR) method;
 measured the photoconductivity upon excitation
 with visible light; analyzed photoluminescence spectra;
 studied the internal structure and composition of the mineral
 inclusions. The obtained results were compared
 with similar materials for the known primary (and sometimes
 alluvial) deposits of the region. Based on the
 study of the typomorphic features of diamonds from lowgrade
 kimberlite pipes from selected fields of the SP we
 conclude that they are characterized by a high content
 of typical rounded minerals of the Ural (Brazilian) type
 with shagreen and plastic deformation bands. This indicates
 a significant dissolution of the mineral in the
 kimberlite of such diatremes, which distinguishes them
 from similar bodies with high diamond content and makes
 it possible to predict the grade already at the initial
 stages of exploration work. Increased content of small
 semitransparent smoky-brown rounded diamonds with
 shagreen and plastic deformation bands for crystals from
 veins was noted, which is also typical for low-grade pipes.

The effect of UV-B irradiation on structural and functional properties of corn and potato starches and their components

In this work, UV-B irradiation, an environmentally friendly modification method, was applied to corn and potato carbohydrates. The influence of irradiation on starch properties was compared with that observed for starch oxidation with NaClO. The changes in the structures of starch carbohydrates were investigated by X-ray diffraction (XRD), electron paramagnetic resonance (EPR) and chromatographic methods. Functional properties such as viscosity, water binding capacity and solubility as well as pasting characteristics and thermodynamic parameters of gelatinization, resulting from structural changes were determined. UV-B irradiation was found to be a milder modification method than chemical oxidation. The potato carbohydrates, especially amylose, appeared to be more susceptible to changes upon irradiation, whereas corn ones, particularly amylopectin, were more stable and their properties changed to a smaller extent. Similarly, functional properties were not significantly influenced by UV-B treatment. EPR studies revealed the mechanism of depolymerization of starch carbohydrates via formation of stable carbon-centered radicals.

Алюминий в кварце месторождения золота Дарасун (Восточное Забайкалье, Россия)

Quartz samples taken from the ore veins of the Darasun gold deposit (Eastern Transbaikalia, Russia) were studied using electron paramagnetic resonance (EPR) and laser ablation (LA) methods. The purpose of the research was to clarify the behavior of the Al impurity during quartz crystallization and its subsequent recrystallization. The results of the research were used to determine the genetic informativeness of the Al impurities concentration in ore quartz. A separate study of the regularities of the distribution of Al impurity in the regions of crystalline structure and in the zones of crystal lattice distortions was carried out. In the regions of crystalline structure, the Al impurity concentration NAL was determined by the concentration of paramagnetic Al–O–-centers associated with the presence of substitutional Al3+ ions. The content of the Al impurity in the zones of crystal lattice distortions was judged by the difference between the gross concentrations of aluminum CAl and the values of NAL. It was taken into account that the intensity and direction of the studied processes can be influenced by the temperature of quartz formation and the degree of its recrystallization. The temperature of quartz formation was estimated by the values of Ti impurity concentration, and the degree of recrystallization was estimated by the content of Li impurity CLi in the mineral. It was found that the amount of Al impurity localized in the zones of crystal lattice distortions is an order of magnitude higher than that present in the zones of crystalline structure. It is shown that this phenomenon is explained by the high ability of the zones of crystal lattice distortions to capture of Al impurity during quartz crystallization. The amount of Al impurity trapped by quartz increases sharply with an increase in the temperature of the mineral formation. In areas of regions of crystalline structure, a different picture is observed − impurity capture during crystallization proceeds with low intensity and is not so critically dependent on temperature. It was found that the Al impurity in the considered zones behaves differently during quartz recrystallization. If Al impurity capture continues in the regions of crystalline structure, then Al impurity removal from quartz can occur in the zones of crystal lattice distortions at high CAl values. Based on the data obtained, the areas of use of aluminum impurity contents as a typomorphic feature of ore quartz were determined. The Al impurity concentrations proved to be suitable for use in cases of low ore formation temperatures, and its gross CAl contents have the prospect of wider use. It is noted that a characteristic feature for quartz from high productivity zones is a negative angle of slope of the CAl(CLi) dependence plot.

STUDY OF DOSIMETRY POSSIBILITIES USING ELECTRON PARAMAGNETIC RESONANCE ON ALANINE FOR ILU-10 ACCELERATOR INP RK

Experimental studying possibilities of the electron paramagnetic resonance (EPR) method application for the dose control using alanine deteectors in the process of technological irradiations with brake radiation at the accelerator ILU-10 INP RK has been carried out. The EPR signal stability and sensitivity of original alanine detectors have been studied, serviceability in standard modes was shown in the range of small doses of brake irradiation (0,005–1 kGy); for dose estimation the calibration on gamma-irrdiation was used. The obtained data confirmed the promise of alanine EPR dosimetry at the ILU-10 accelerator INP RK.

EPR STUDY OF ACCUMULATION AND TOXIC EFFECT OF IRON AND COPPER DURING THE DEVELOPMENT OF Solanum tuberosum L. in vitro

The migration and accumulation of iron and copper ions in the process of growing Solanum tuberosum L vial potatoes have been studied. The form and content of the metals in the tissues of potatoes grown under factorostatic conditions have been determined by elemental analysis and electron paramagnetic resonance (EPR) method. The toxic effect of the studied heavy metals has been expressed in terms of physical-chemical characteristics (change in the EPR signals and metal accumulation in plant organs) and biometric parameters with an increase in the content of metal salts in the nutrient medium. In addition, the EPR spectra showed a narrow singlet typical for stable semiquinone radicals.

Application of the electronic paramagnetic resonance method for detecting radiation-processed food products

This paper presents the results of work on studying the capabilities of EPR spectroscopy for identifying certain types of food products treated with ionizing radiation at various doses, determining the dose and time elapsed since the product was treated with ionizing radiation. The samples were examined for 270 days. For the prepared samples, the post-effect of irradiation with ionizing radiation was studied, which manifested itself in a change in the number of paramagnetic centers in the sample.

The Comparison of Advanced Electrospun Materials Based on Poly(-3-hydroxybutyrate) with Natural and Synthetic Additives.

The comparison of the effect of porphyrins of natural and synthetic origin containing the same metal atom on the structure and properties of the semi-crystalline polymer matrix is of current concern. A large number of modifying additives and biodegradable polymers for biomedical purposes, composed of poly(-3-hydroxybutyrate)-porphyrin, are of particular interest because of the combination of their unique properties. The objective of this work are electrospun fibrous material based on poly(-3-hydroxybutyrate) (PHB), hemin (Hmi), and tetraphenylporphyrin with iron (Fe(TPP)Cl). The structure of these new materials was investigated by methods such as optical and scanning electron microscopy, X-ray diffraction analysis, Electron paramagnetic resonance method, and Differential scanning calorimetry. The properties of the electrospun materials were analyzed by mechanical and biological tests, and the wetting contact angle was measured. In this work, it was found that even small concentrations of porphyrin can increase the antimicrobial properties by 12 times, improve the physical and mechanical properties by at least 3.5 times, and vary hydrophobicity by at least 5%. At the same time, additives similar in the structure had an oppositely directed effect on the supramolecular structure, the composition of the crystalline, and the amorphous phases. The article considers assumptions about the nature of such differences due to the influence of Hmi and Fe(TPP)Cl) on the macromolecular and fibrous structure of PHB.

Analysis of the Osseointegration Process of Dental Implants by Electron Paramagnetic Resonance: An In Vivo Study.

This research work presents an analysis of the process of an implant’s osseointegration to the jawbone tissue. The purpose of this work was to describe the processes of assimilation and the biochemical dynamics which occur during dental implantation using implants with different macro-microstructure surfaces at the level of stable free radicals using the electron paramagnetic resonance (EPR) method. The experimental investigation was conducted on seven Vietnamese minipigs over twelve months old and weighing up to 30 kg using implants with various macro-microstructure surfaces (SLA, RBM, and HSTTM) and implantation systems, namely the Adin, Sunran, Biomed, and Osstem systems. The integration of the implant into the bone triggered biochemical processes with the formation of stable free radicals. The EPR method was used to identify the formed paramagnetic species and to study the dynamics of the interaction between the surface of the implant and the bone after one and two months. The concentration of carbonate surface centers increased with the time that the implant was connected to the hard tissue. The “Sunran” and “HSTTM” were established as the most suitable implantation system and surface type, respectively, thanks to the highest rate of osseointegration (assimilation) with the bone (hard) tissue. Thus, the EPR method provides the opportunity to study implantation processes.

Organomorphic Carbon Preform Formation Mechanism

Looking for ways to increase the structural uniformity of ceramic matrix composites (CMC) resulted in the development of organomorphic composites (C/C, C/SiC, SiC/SiC) where the filament diameter is comparable to the space between the filaments. The structural uniformity of the aforesaid CMCs is determined by their reinforcing preform; however, the mechanism of formation of this structure from polymer fibers remains unclear. This paper discusses an investigation of pressed specimens of the OKSIPAN® nonwoven fabric based on Pyron® polyacrylonitrile (PAN) fibers that were underoxidized as was determined using the electron paramagnetic resonance and microtomography methods. Using electron scanning microscopy, thermomechanical analysis and X-ray tomography, cementation of the preform due to the release and condensation of readily-polymerizing resin-like substances on the fiber surface after pressing at 180 °C was shown to be mainly responsible for retaining the mutual positions occupied by the fibers during pressing. The carbonized residue of the resin-like substances binds the fibers after pyrolysis. The other reason for organomorphic carbon preform consolidation is autohesive interaction of insufficiently cross-linked cores of the PAN fibers, since their thermal oxidation during pyrolysis at up to 1000 °C is hindered by the relatively high density of the compressed polymer preforms. The combination of pressing, thermal stabilization and pyrolysis results in the formation of the organomorphic carbon preform that features a relative density of at least 0.3 and a collection of pores, their normalized diameter ranging between 4 and 40 μm.

Evaluation and Characterization of Ultrathin Poly(3-hydroxybutyrate) Fibers Loaded with Tetraphenylporphyrin and Its Complexes with Fe(III) and Sn(IV).

The effect of small additions (1–5 wt.%) of tetraphenylporphyrin (TPP) and its complexes with Fe (III) and Sn (IV) on the structure and properties of ultrathin fibers based on poly(3-hydroxybutyrate) (PHB) has been studied. A comprehensive study of biopolymer compositions included X-ray diffraction (XRD), differential scanning calorimetry (DSC), spin probe electron paramagnetic resonance method (EPR), and scanning electron microscopy (SEM). It was demonstrated that the addition of these dopants to the PHB fibers modifies their morphology, crystallinity and segmental dynamics in the amorphous regions. The annealing at 140 °C affects crystallinity and molecular mobility in the amorphous regions of the fibers, however the observed changes exhibit multidirectional behavior, depending on the type of porphyrin and its concentration in the fiber. Fibers exposure to an aqueous medium at 70 °C causes a nonlinear change in the enthalpy of melting and challenging nature of a change of the molecular dynamics.

Experimental study and reaction mechanism on the process of Br addition for mercury emission control

Application of halogen additive (CaCl2, CaBr2) has recently been shown to decrease Hg0 concentration significantly in the hazardous waste incineration flue gas. However, the reaction mechanism of Hg0 oxide active substance has currently not yet been studied. In this paper, the effect of CaBr2 on Hg0 oxidation under different combustion conditions and the reaction mechanism of effective reaction components (bromine free radicals) detected by the EPR (Electron Paramagnetic Resonance) method are studied. For the first time, the correlation between bromine radical and Hg0 oxidation is shown, which eventually affects the transformation path of Hg0 in the flue gas. Under different working conditions, the oxidation effect of CaBr2 solution additives on Hg0 in flue gas has been verified in the experiment platform. CaBr2 can still effectively oxidize Hg0 in complex flue gas conditions of the hazardous waste incineration plant. These results provide a new fundamental understanding of the oxidation path of Hg0 under the influence of bromine free radicals and show that spraying calcium bromide solution is an effective means to avoid atmospheric Hg0 emissions, contributing to its global distribution in a significant way.

Glass-forming region and optical properties of TeO2 – MoO3 – La2O3 glasses

Several properties of TeO2 – MoO3 – La2O3 glasses were studied. The glass-forming region in the TeO2 – MoO3 – La2O3 system covers the composition range from 7 to 78 mol.% TeO2, from 7 to 78 mol.% MoO3 and from 0 to 30 mol.% LaO1.5. Optical transmission of glasses was investigated in the wavelength range from 450 to 2000 nm. In this spectral region, the bands of Mo+5 atoms cause the main contribution to light absorption. The presence of these atoms was confirmed by electron paramagnetic resonance method. The specific absorption coefficient attributed to Mo+5 atoms was found (0.009 ± 0.002) cm−1/ppm ((140 ± 30) cm−1/wt.%.) at 990 nm.

Nature of paramagnetic defects in black titanium dioxide nanotubes

Electron paramagnetic resonance (EPR) spectroscopy was used to study the nature of defects in black titanium dioxide nanotubes (TiNTs) prepared by electrochemical oxidation of titanium in ethylene glycol. The TiNTs that have intensive black color were formed under thermal treatment of amorphous TiNTs in hydrogen at 500 °C. The work aimed to reveal the role of various defects in the black color of TiNTs. Amorphous carbon has been found to contribute mainly to the deep black color of anatase-type TiNTs. Considerable growth in •С-radicals concentration was detected by the EPR method in amorphous TiNTs under their heat-treatment in hydrogen. The radicals are resulted from the reduction of carbon-containing products of electrochemical and thermal decomposition of ethylene glycol. The dependence of the •С-radical signal position in EPR spectra on the axis of the applied magnetic field testifies for a predominant orientation of graphite-like networks along the direction of TiNTs growth. The Gaussian shape and broadness of the EPR lines are caused by the superposition of several signals from different carbon states. The conditions of synthesis that might result in the occurrence of Ti3+ state and oxygen vacancies in titanium oxide were analyzed. The absence of Ti3+ signals in the EPR spectra of TiNTs reduced in hydrogen can be explained by the high concentration of Ti3+ centers as well as by the formation of [Ti3+–VO–Ti3+] or [VO–Ti–VO]n– complexes, which are inactive in EPR. The indicated defects might also contribute to titanium dioxide color.

Magnetic resonance tracking of copper ion fixation on the surface of carboxylated nanodiamonds from viewpoint of changes in carbon-inherited paramagnetism

Detonation nanodiamonds with a particle size of 5 nm and a carboxylated surface are easily modified by doubly charged copper ions to form copper chelate complexes. The concentration of copper complexes in a dry powder of such nanodiamonds is well monitored by the method of electron paramagnetic resonance, both by the signal width of intrinsic paramagnetic centers in nanodiamonds and by the signal shape for the surface Cu2+ ions themselves, including the set of hyperfine splitting lines for the parallel component and the line with an unresolved hyperfine structure for the perpendicular component.

The impact of geological factors on the sorption capacity of gas and fat ranks of coal in the krasnoarmeyskiy district

At present, based on the research of the conditions and factors of outburst hazard of coal beds, various predicting methods have been developed grounded on contemporary views concerning the nature and mechanism of gas-dynamic phenomena. One of the main factors affecting the outburst hazard of coals is gas saturation, which is determined by the sorption capacity of coals. The sorption properties of coal matter are significantly determined by the degree of coal transformation (metamorphism). Therefore, the analysis of the data obtained for a coal matter of the same rank makes it possible to reveal the role and importance of factors that have formed the parameters of the signals observed by EPR (electron paramagnetic resonance) spectroscopy. These signals define the features of the sorption coal-gas interaction for a particular sample. It is established that the average values of the concentration of paramagnetic centers are (2.29 ± 0.36) and of contingency - (0.476 ± 0.02), and the calculated value of the sorption capacity of coals (24.3 ± 0.29) can be considered basic for gas and fat ranks of coals in the Krasnoarmeyskiy district. Minor deviations from the basic parameters can be caused by various geological and technological factors. Significant deviations of the average values for the sorption capacity of coals can be caused by tectonic processes. The purposeis to research the impact of geological factors on the sorption properties of gas and fat ranks of coals determined by the EPR method in the mines of the Krasnoarmeyskiy district. During the research, the following parameters were defined: 1) the integrated intensity of the EPR spectrum - the concentration of paramagnetic centers (Na) in the matter under research, which characterizes the conjoint impact of external factors on the coal matter, and 2) the contingency coefficient (Ksc), i.e. the number and status of the conjugate system in the molecular structure of a matter, which characterizes the transmitting depth of structural transformations (a degree of structuredness) of fossil organics at the nanolevel. As a result, it is found that various factors acting in different directions affect the calculated value of the sorption methane capacity of coals. The average sorption capacity of gas and fat ranks of coals from the Krasnoarmeyskiy district is 24.3 ± 0.29 and mainly depends on the deformation conditions. The average concentrations of paramagnetic centers are (2.29 ± 0.36), and of contingency (0.476 ± 0.02). The calculated value of the sorption capacity of coals (24.3 ± 0.29) can be considered as the base one for the gas and fat ranks of coals in the Krasnoarmeyskiy district. Minor deviations from the basic parameters can be caused by various geological and technological factors. Significant deviations in the average values of the coals sorption capacity can be caused by tectonic processes.