Using the spectrum of selective reflection (SR) of laser radiation from the boundary of the surface of the dielectric window of the spectroscopic nanocells – pairs of rubidium atoms, the value of the magnetic field applied to the nanocell is measured. A method is proposed for calculating the magnetic induction B in the range of 0.1–6.0 kG based on the ratio of the frequency intervals between atomic transitions, which greatly simplifies the determination of B, particularly, there is no need for a reference spectrum at B = 0. To implement the SR process a 300-nm column of vapors of Rb atoms is used, and atomic transitions with a subDoppler spectral width of 80–90 MHz are formed. This leads to frequency separation of transitions in SR spectrum that is important for the proposed method. SR spectrum can be analyzed using a specially designed computer program that accelerates the data processing. The small thickness of the vapor column allows high spatial resolution, which is important in the case of inhomogeneous magnetic fields. 

he π-conjugation pathway was identified and the degree of aromaticity for the NH-tautomers of the free base corroles was determined by quantum chemistry methods and absorption spectroscopy. Different participation of the macrocycle skeletal atoms in formation of the π-conjugation pathway was established, and it was supposed that conjugation pathway consisting of 18 π-electrons were dominating. At the same time, each of two NH-tautomers possesses its own distinct π-conjugation pathway, which provides the differences in the aromaticity degree. It was shown that architecture of the peripheral substitution of a macrocycle influences the degree of aromaticity. Method of the control over the equilibrium between two NH-tautomers was proposed and experimentally proved. It consists in the design of the electronic density distribution in macrocycle which is characteristic for one of the tautomers. 

In the inverse problem for a complex vibronic analogue of the Fermi resonance, the matrix elements of the electron-vibration interaction should be obtained from experimental data, energies Ek and intensities I_k (k = 1, 2, …, n; n ³ 3), a “conglomerate” of lines in the spectrum. This problem in the direct-coupling model, where the Hamiltonian H^DIR is specified by the energies of the “dark” states Ai and the matrix elements of their coupling with the “bright” state Bi (i = 1, 2, …, n –1), was solved by the author on the basis of algebraic methods. It is shown that the Hamiltonian H^DW of the doorway-coupling model, in which the “bright” state has “interaction” with only single distinguished |DW> state, can be obtained from the Hamiltonian H^DIR using the Householder triangularization method, namely, by the similarity transformation H^DW = PH^DIRP, where P is the reflection matrix which is constructed from the Bi values. The expressions for main elements of the doorway model, namely, the energy of the |DW> state and the matrix element of its coupling with the "bright" state, are obtained. For pyrazine and acetylene molecules, the matrix elements of the Hamiltonian H^DW are calculated using the data of the electronic-vibrational-rotational spectra. 

The spectral properties of a new benzothiazole dye modified with polyethylene glycol have been investigated. A strong dependence of the fluorescence quantum yield on the viscosity and polarity of the medium has been shown, i.e. the conjugation of the dye with polyethylene glycol does not lead to the loss of the properties of the molecular rotor, while significantly reduces its aggregation. When incorporated into amyloid fibrils, the quantum yield of the dye increases by more than 40 times; the new dye can be regarded as an efficient fluorescent probe for amyloid fibrils detection and research. In this case, not only the intensity, but also the position of the absorption spectrum can be used as a sensitive parameter. The presence of blood plasma proteins (albumins) in the solution has practically no effect on the position of the absorption spectrum and has little effect on the fluorescence intensity of the probe. 

We present a combined experimental and theoretical study of the effect of magnetic field on the luminescence from an ensemble of NV centers in diamond. It was found that the intensity of infrared luminescence associated with transitions between singlet levels of NV centers shows a pronounced increase of a near-zero magnetic field. The influence of the power and polarization of laser radiation on the amplitude and shape of the revealed local maximum in IR-luminescence of NV centers is investigated. An eight-level photophysical model of an NV center in the presence of an arbitrarily directed magnetic field has been constructed and on its basis the calculation has been performed of the luminescence intensity emitted by an ensemble of NV center, both in the visible and infrared regions of the spectrum. It is shown that the phenomenological allowance for the cross-relaxation of NV centers between each other and with other paramagnetic centers in a diamond within the framework of this model allows describing the experimentally observed fluorescence features of an ensemble of NV centers in the presence of weak magnetic fields. 

New analytical representations for the truncated spectral characteristics of the four-point coherence function of a laser beam propagating in a turbulent medium are obtained. These representations are valid for any level of fluctuations of the refractive index in air. For two particular cases they turn into exact analytical representations previously derived by the authors with using of an integro-functional equation for truncated spectral characteristic of the four-point coherence function. A constructive procedure for obtaining approximate analytical expressions of the four-point coherence function of a laser beam propagating in a turbulent medium is proposed. 

The long-wavelength edge of the fundamental absorption band of thin Y2O3 films obtained by radiofrequency ion-plasma sputtering is investigated. The edge of interband absorption after annealing of the films in an atmosphere of argon, oxygen, or a mixture of these gases is shown to be approximated well by the Urbach empirical rule. Diffractograms of the obtained films were studied and a model of a heavily doped or defective semiconductor in the quasi-classical approximation was used to analyze the experimental results. This model allows determining the radius of the basic electronic state, the screening radius, and the rootmean-square potential depending on the sputtering atmosphere.

The absorption spectra of Si/SiO₂/Si₃N₄/Si⁺ and Si/SiO₂/Si⁺ structures with an island surface layer are calculated using the finite difference time domain method. The absorption spectra were modeled depending on the thickness of the substrate and its doping level. It was found that the thickness of the i-Si substrate does not affect the overall absorption of the structure. At the same time, an increase in the thickness of the n-Si substrate leads to an expansion of the absorption band with an intensity of more than 70%. It is established that the doping level of the substrate affects the absorption value of the structures and bandwidth with an absorption value above 80%. It is shown that a wide absorption band with intensity of more than 80% occurs at the doping level of the substrate in the range of 2 × 10¹⁹—5 × 10¹⁹ cm^–3 . Dispersion relations in the Si⁺/SiO2/Si⁺ structure with an unstructured surface layer are obtained. These dispersion relations may indicate the existence of plasmon oscillations in the system. It is established that a violation of the phase synchronization of the modes at both Si/dielectric interfaces at a significant difference between the doping levels of the substrate and the surface layer can lead to a decrease in the absorption. 

We investigated the radiative properties of InGaN/GaN heterostructures with multiple quantum wells (MQWs) grown on silicon substrates with different thicknesses of quantum wells at optical excitation. The correlation of laser and photoluminescent properties with the surface morphology of the gallium nitride coating layers and the density of V-defects has been established. It is shown that, with a growth in the density of V-defects, the threshold power density of the excitation of the generation of InGaN/GaN heterostructures with MQWs increases. 

The formation and heating of laser plasma under the irradiation of silicon in ambient air by pulsed laser radiation with wavelengths of 355 and 532 nm at radiation power density up to 5 GW/cm2 has been experimentally investigated. An increased efficiency of the formation and heating of ablation plasma under bichromatic irradiation of silicon with advanced action of nanosecond pulses with a wavelength of 355 nm has been established. 

An algorithm for mathematical processing of the Mössbauer spectra of supersaturated disordered solid solutions by the Tikhonov regularization method using a double convolution of the Lorentz function and two Gaussians is proposed. By the examples of spectra of supersaturated disordered solid solutions Fe_100–xGe_x (x = 10—25 at.%) and Fe₇₅Si₁₅Al₁₀, it is shown that the algorithm allows more correct processing, which provides a reliable distribution function of the hyperfine magnetic field. It is shown that to take into account the statistical ensemble of nonequivalent local atomic configurations of Fe atoms in disordered supersaturated solid solutions, it is necessary to use not only the convolution of two Gaussian functions, but also the projection scaling factor of the hyperfine magnetic field onto the velocity scale. 

Nateglinide (NAT) is an oral antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus. We evaluated the NAT stability under various forced degradation tests (acidic, basic) and predicted the degradation mechanism of the NAT molecule in the gaseous phase and aqueous media. A firstorder derivative spectrophotometric method was used for the identification of NAT and the products of its degradation. NAT appeared to be stable in acidic but not in basic media. A probable reaction path of the NAT molecule with OH radicals was analyzed. The optimized geometry was calculated with Gauss View 5. Subsequently, the lowest energy status was determined through geometric optimization using Gaussian 09 software. Aiming to determine the intermediates in the photocatalytic degradation mechanism, the geometric optimization of the molecule was realized using the density functional theory method. The activation energy for the probable reaction path was calculated, and their most stable state from the thermodynamic perspective determined for the gaseous phase and aqueous media. The predicted mechanism was confirmed by comparison with the experimental results on simple structures reported in the literature. 

Surface-enhanced Raman scattering (SERS) technology was combined with nanotechnology to detect the Raman intensity of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in saliva and of three kinds of populations (healthy volunteers, patients with gingivitis, and patients with periodontitis). The Raman intensities of IL-1β and TNF-α in the saliva of the periodontitis group were significantly higher than those of the control and gingivitis groups (P = 0.00). The Raman intensities of the two inflammatory factors in the gingival crevicular fluid (GCF) of the periodontitis group were also significantly higher than those of the other two groups (P = 0.00). In the same group, the Raman intensities of IL-1β and TNF-α showed no significant difference between the saliva and GCF samples, respectively (P > 0.05). Combining SERS technology and nanotechnology can aid in detecting the Raman intensity of inflammatory factors using saliva and GCF more effectively than traditional methods. 

The combination of continuous wavelet transforms (CWT) with zero-crossing strategy and spectral ratio treatment was described for simultaneous determination of atorvastatin (AT) and rosuvastatin (RVS). Meyer-CWT and Gaus8-CWT of wavelet families were found to be appropriate for spectral analyses of original overlapping signals. Also, it was established that Morl-CWT and fk8-CWT were applicable to signal analysis of the ratio spectra of AT/RVS and RVS/AT. The calibration graphs of CWT methods for AT and RVS were obtained from the working concentration ranges of 5–25 and 10–30 µg/mL, respectively. The applicability of proposed signal processing methods was successfully tested for simultaneous detection of the AT and RVS in combination dosage formulations (without a primary separation). The CWT approach also stayed within good analytical parameters (precision, accuracy, and detection limit) for the management of quality and routine analyses of both drugs in comparison with derivative procedure. The results of proposed method were in agreement with those obtained from HPLC. 

The article presents the results of studies of infrared absorption spectra of saturated vapors of alcohols and alcohol-containing mixtures in the range of 1.3—1.5 mm. A method was developed for the quantitative determination of the composition of water-alcohol mixtures based on the use of multiple linear regression, and a range of methanol concentrations was determined, in which the nonlinearity of the dependence of the concentration of alcohols in saturated vapors over a liquid mixture on the concentration of alcohols in this liquid mixture does not significantly affect the results of analysis of the mixture composition. A method for optimizing a set of wavelengths for multiple linear regression, based on minimizing the mean-square error in determining the concentration is proposed and implemented. The developed methods make it possible to determine the presence of small (<1%) amounts of methanol against the background of large amounts of ethanol and water using relatively inexpensive and accessible spectroscopic equipment.

The comparative study on interaction of bisbenzimidazole compound Hoechst 33258 and thiazine dye methylene blue (MB) with bovine serum albumin (BSA) was carried out by spectroscopic methods. Denaturation curves as well as absorption spectra and differential absorption spectra of protein-ligand complexes were obtained. Denaturation temperature of albumin complexes of BSA with Hoechst 33258 was shown to decrease with the growth of concentration ratio of ligand/protein, while for MB, vice versa, denaturation temperature increases. Changes in absorption spectra and differential absorption spectra of the complexes of ligands with albumin were revealed, which result from the binding of these DNA-specific ligands to protein. It is supposed that at the interaction of Hoechst 33258 with BSA some loosening of protein compact structure occurs due to the partial loss of helicity of a-structures, while for MB an increase of the protein compact structure takes place. 

A technique for the express analysis of the products of technological processes is described, which was developed using the Raman spectroscopy method. The analysis of the Raman spectra includes the interpretation of the spectral bands, taking into account the values of the characteristic frequencies of the vibrational spectra of organic compounds, as well as the determination of the integral intensities of the corresponding spectral ranges. By example of the real time control procedure for the technological process of monosilane synthesis, the express analysis of tetraethoxysilane, which is a by-product of this technological process, is carried out. Significant advantages of using the express analysis method are demonstrated, which provide control over the normal course of the technological process and obtaining results that allow making adjustments to the process flow diagram in order to optimize it. 

The spectral distribution of the photoconductivity and the temperature dependence of the photocurrent of MnIn2S4 single crystals are investigated. The intrinsic, impurity photoconductivity and a maximum at an energy of 2.69 eV, which is associated with the intracenter transition of Mn²⁺ ions (⁶A1®⁴A1), are revealed in the photoconductivity spectrum. The region of the wavelengths of 600–1000 nm appears with an excess of manganese in the crystals and is caused by a donor defect. At temperatures of 80—145 K, the increase in the photocurrent is associated with the thermal depletion of the adhesion levels. The activation energy of the adhesion levels is determined. 

Comminution is widely used in the deep processing of coal resources. Different chemical structures in coals can influence follow-up procedures significantly. A planetary ball mill was used as a comminution device, and its effects on the grain size and chemical structure of anthracite from Ningxia, China were studied. Comminution kinetics were studied and qualitative and quantitative analyses of functional groups were done by IR spectrometry. The results demonstrate that product size distribution of anthracite from Ningxia conformed to the n-order kinetic model and the grain size reached −42 nm after 24 h. The peak intensity of the IR spectra increased markedly, and the surface activity of anthracite powder was enhanced after ultrafine comminution. Penta-substituted benzene rings of aromatic hydrogen were the dominant group in raw anthracite, while tris-substituted benzene rings of aromatic hydrogen became the dominant form after 24 h of ultrafine comminution. During ultrafine comminution, cyclization of aliphatic chains, dehydroaromatization of cycloparaffin, substitution reactions of orienting groups on aromatic rings, and decarboxylic reactions of benzene rings might occur. Although raw anthracite shows a relatively high degree of metamorphism, its particles show stronger activity and can absorb more oxygen after ultrafine comminution, thus increasing oxygen enrichment. The CH in the aliphatic hydrocarbons of ultrafine anthracite basically disappeared, and CH2 was more easily lost than CH3 during ultrafine comminution. Oxygen-containing functional groups in anthracite were altered or some of their elements reacted with oxygen, which decreased the amount of free OH groups on anthracite particle surfaces. During ultrafine comminution, the stability of hydrogen bonds was ranked OH…π > OH…OH > free OH groups > OH…ether > OH…N > cyclic OH tetramers. These changes indicate that the ultrafine anthracite comminution process is also accompanied with chemical reactions. The results provide a reference and guidance for exploring changes in the molecular structures of ultrafine anthracite and follow-up deep processing. In particular, the occurrence of mercaptan -SH and FeS2 implies that sulfur exists in anthracite in both organic and inorganic forms. The absorption peak of ultrafine pulverized kaolinite was intensified, indicating that minerals were dissociated and more impurities were exposed after comminution. 

A new mononuclear zinc(II) complex Zn(niacin)₂(H₂O)4 (1) is synthesized. The interaction of 1 with calf thymus-DNA is investigated by UV-Vis and fluorescence spectrometry, and the apparent binding constant (K_app) value is established as 4.6×10⁵ M^–1 . It is found that the quenching mechanism between bovine serum albumin and 1 might be a static quenching procedure with one binding site. Further, the anticancer activity of the complex on three human tumor cells lines (HT29, HepG2, and MCF-7) is studied. The IC₅₀ values of 1 on HT29, HepG2, MCF-7 are 114.1±8, 146.7±14, and 319.2±13 µM, respectively. 

1-Naphthylacetic acid (C10H7-CH2COOH; HL) is a synthetic commercial plant hormone widely used in agriculture as a plant growth regulator. Five complexes between metal and this hormone were synthesized and structurally characterized: [MnL₂(H₂O)₂] (A), [CoL₂(H₂O)₂] (B), [NiL₂] (C), [CuL₂(H₂O)₂] (D), and [ZnL₂] × H₂O (E). Next, IR, ¹H NMR, UV-Vis, thermogravimetry, magnetic moment, and elemental analyses were used to characterize the complexes, and their morphological properties were assessed using XRD and SEM techniques. These analyses indicated that two L– molecules were coordinated to the metal ion by their bidentate carboxylate groups. Finally, the complexes were screened in vitro against several microbes (bacteria and fungi) using the Kirby–Bauer disc diffusion method. Complex C showed antifungal activity against Candida albicans with a potency that was 15% higher than the antifungal drug amphotericin B. 

The binding interactions between human serum albumin (HSA) and two anti-diabetic drugs, saxagliptin (SXG) and vildagliptin (VDG), are studied. Different approaches are adopted, including native fluorescence, synchronous fluorescence, UV–Visible absorption, and Fourier-transform infrared (FTIR) analysis, in addition to molecular docking simulations. Moreover, the thermodynamic parameters of the interactions are determined at different temperatures. The obtained results indicate that the intrinsic fluorescence of HSA is quenched via a static mechanism. Values for the binding constant, Ka, are 4.0×10⁴, 2.49×10⁴, and 2.42×10⁴ L/mol for SXG, and 1.13×10⁴, 8.54×10³, and 7.15×10³ L/mol for VDG at 298, 310, and 318 K, respectively. Evidence from competition experiments with site markers indicate that both SXG and VDG bind HSA primarily at or near site I of the protein. FTIR spectroscopy data indicate an alteration of the protein conformation in the presence of SXG or VDG. Indeed, the results of different spectroscopic analyses indicated that noticeable changes in the protein structure conformation occur following the addition of SXG or VDG. 

A simple, cost-effective, and stability-indicating first-derivative spectrophotometric technique for quantifying Paliperidone in different pharmaceutical formulations is developed. In this method, the drug shows a maximum dA/dλ at 245 nm. The drug follows Beer–Lambert’s law in the concentration range 2.5–70 µg/mL. Various degradation studies for the drug, such as acid hydrolysis, base hydrolysis, thermal, oxidative, and photolytic degradation are performed, and the results thereof are within the acceptable limit. The analytical method validation parameters like linearity, LOD, LOQ, precision, accuracy, etc. are conducted for the method as per the ICH Q2R(1) guideline, and the values are within the allowable range. Hence, for the determination of the Paliperidone quantity in pharmaceutical dosage forms, the developed process is a feasible one. 

We herein report a universal calibration curve for the UV-visible spectrophotometric determination of the concentration of polymerizable dyes in solution. The method has been successfully applied to construct a calibration curve of methylene blue in water that is applicable over a wide range of methylene blue and chloride concentrations, regardless of both the aggregate concentration distribution and the temperature. In addition, it was found that the molar fractions of each methylene blue species in solution could be well approximated by means of simple algebraic expressions in the A650/A607 absorbance ratio. 

The interaction between human serum albumin (HSA) and omega 3-6-9 fatty acids (omega-3, omega-6, and omega-9), as unsaturated fatty acids, has been investigated using various methods including UV-Vis spectrophotometry, circular dichroism (CD) spectroscopy, ELISA, lifetime and fluorescence anisotropy measurements, and the visual molecular dynamics (MD) simulation. The thermodynamic parameters of HSA thermal and chemical denaturation were assessed with and without omega 3-6-9 fatty acids. The T_m and ΔG⁰ (298K) of sole HSA were 327.7 K and 88 kJ/mol respectively. These figures for HSA treatment with 10 µM omega-3, omega-6, and omega-9 were 326.2 K and 87 kJ/mol, 319.07 K and 87 kJ/mol, and 313.23 K and 86 kJ/mol respectively. The same manner of reduction in Gibbs free energy, which is a protein stability criterion, was achieved in chemical denaturation by urea in presence of omega 3-6-9 fatty acids. The interaction of omega 3-6-9 fatty acids with HSA was confirmed after comparing it with L-thyroxin through ELISA assay. Althoug, evaluation of the regular secondary structure of HSA using CD showed a minor change after incubation with omega 3-6-9 fatty acids, its tertiary structure revealed an observable fluctuation. Thus, it seems that the interaction of omega 3-6-9 fatty acids with HSA leads to instability and partial structural changes. Furthermore, the molecular docking results indicated that the binding affinity of omega-3, omega6, and omega-9 to subdomain ІІA of HSA was higher than subdomain ІІIA. These results provide valuable insights into the binding mechanism of omega 3-6-9 fatty acids to HSA, which could play an important role in medicinal drug delivery. 

Severe air pollution is a serious threat to public health in the Yangtze River Delta region, where high concentrations of particulate matter are often observed in winter. In the present study, a serious aerosol pollution incident in the western Yangtze River Delta, China, was investigated by using joint inversion of CALIPSO and ground-based lidar in Hefei during 17–22 January, 2019. The data of the past two years were used in this study, and four typical weather cases were selected for comparative verification—namely, fine weather (less cloud, good air); cloudy weather (good air, no haze); moderate pollution weather (moderate haze, no cloud); and severe pollution weather (heavy haze, cloud). The vertical profile of aerosol backscatter as the satellite passed through Hefei city was given by the data of the CALIPSO satellite-borne lidar, CALIOP, which was compared with the vertical distribution of the range-corrected signal of ground-based lidar. Combined with analysis of meteorological data, the results showed that satellite–ground lidar can be used to observe the effect of aerosol changes on weather effectively. Subsequent experiments observed and tracked severely polluted weather event, and the data on the aerosol boundary layer was obtained which was a severe trans-boundary air pollution. The serious pollution period occurred from 22:00 to 04:00 on January 19 to 20, 2019, when the aerosol boundary layer was at its lowest (less than 0.5 km) and the boundary layer height ranged from 0.5 km to 2.2 km in other periods. Then, based on analysis of near-surface data, the changes in the boundary layer during the pollution process and the possible causes of these changes were analyzed. It was concluded that, during the pollution process, the height of the aerosol boundary layer in the Hefei area showed an obvious negative correlation with the concentration of PM2.5. Finally, HYSPLIT results showed that the source of pollution weather was mainly aerosol particles blown from the north. The results of this study provide a basis for satellite- and ground-based lidar joint observation under different weather types, as well as help in the study of urban weather change and pollution prevention. 

In rubber tire production, three popular types of rubber vulcanizing accelerators exist that are similar in appearance (i.e., 2-Mercaptobenzothiazole, 4,4′-dithiodimorpholine, and tetramethyl thiuram monosulfide). Because the rubber vulcanizing accelerator has a great influence on the vulcanized rubber characteristics, it is necessary to classify and identify the three popular types of rubber vulcanizing accelerators to avoid using the wrong accelerator during tire production and to ensure the tire quality. The THz spectra of the accelerator samples were measured using a terahertz time-domain spectral system (THz-TDS) in a frequency range of 0.3–1.6 THz. An extreme learning machine (ELM) model was constructed to classify the three popular types of rubber vulcanizing accelerators via terahertz absorption spectra. To improve the classification accuracy of the model, a particle swarm optimization ELM model was constructed possessing a higher classification accuracy than the ELM model in the classification and identification of rubber vulcanizing accelerators. 

A dual-band metamaterial absorber based on nested nanostructures is proposed. Finite-difference timedomain simulations revealed two resonance absorption peaks with narrow half-widths in the mid-infrared, with center wavelengths at 3.87 and 4.57 µm. The structure exhibited extremely high sensitivity with no polarization sensitivity. Triple-band absorption was observed by controlling the thickness of the top pattern layer. The effects of various metallic materials and geometric structures on the absorption are discussed. The nested infrared-absorbing structure has potential applications in sensors and detectors. Furthermore, multiple absorption peaks via thickness changes provide a theoretical basis for future research on multiband absorption. 

Для определения энрофлоксацина (EFX) в фармацевтических препаратах разработаны три спектрофотометрических метода. Метод А основан на измерении поглощения EFX в 0.1 M HOAc на длине волны 315 нм. В методе В использованы реакция образования кетоксима и измерение продукта оксима EFX на 275 нм. Метод С является косвенным и основан на окислении EFX церием(IV), реакции непрореагировавшего церия(IV) с р-толудином (p-TD) и измерении поглощения окрашенного раствора на 540 нм. Закон Бера соблюдается в диапазонах концентраций EFX 1.2–24, 1–8 и 1–20 г/мл для методов A, B и C соответственно, с молярными коэффициентами экстинкции 1.52 × 10⁴, 3.86 × 10⁴ и 6.6 × 10³ л/моль/см. Коэффициенты регрессии калибровочных линий 0.9996, 0.9913 и –0.9965 для методов А, В и С соответственно. Для каждого метода получены пределы обнаружения и количественного определения, проверены их точность и надежность. Предложенные методы применены для определения EFX в таблетках. Результаты сопоставлены со стандартным методом и установлено их хорошее согласие. В экспериментах по восстановлению использована стандартная процедура добавления для дальнейшего подтверждения точности методов. Результаты экспериментов удовлетворительные. Стабильность, указывающая на потенциал метода А, изучена путем проведения кислотного и щелочного гидролиза, окислительного, термического и ультрафиолетового разложения EFX с последующим измерением поглощения полученных растворов EFX на длине волны 315 нм. Результаты исследования разложения свидетельствуют о невосприимчивости EFX к стрессовым условиям.