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Rapid Determination of Tetracyclines in Milk by the Method of Mass Spectrometry High Resolution

Authors: Amelin V. G., Amelin A. I.

The method of determination of tetracycline antibiotics (tetracycline, chlortetracycline, oxytetracycline, doxycycline) in the milk of methods HPLC-MS/MS/MS and HPLC-QTOF-MS, with a simple and rapid sample preparation. The ranges defined concentrations of tetracyclines in milk sample of 1 g was 1–200 μg/kg. Relative standard deviation of the results of the analysis does not exceed 7%. The analysis duration 30–40 minutes.

Возможности стационарной и разрешенной во времени сенсибилизированной флуоресценции при определении некоторых тетрациклинов в мицеллярных средах

Authors: Smirnova T. D., Паращенко И. И., Zhelobitskaya E. A.

Изучены особенности влияния природы второго лиганда, мицелл ПАВ на интенсивность сенсибилизированной флуоресценции хелатов европия (III) с некоторыми производными тетрациклина. Предложен подход к флуориметрическому определению суммы трех тетрациклинов и повышению избирательности, заключающийся в измерении интенсивности эмиссии хелатов с помощью стационарной и разрешенной во времени флуоресценции. Установлено оптимальное время задержки измерения

Phase Diagram of the Potassium Thiocyanate – Water Binary System

Authors: Il’in K. K., Cherkasov D. G.

The phase diagram of the potassium thiocyanate–water binary system was studied by the visual polythermal method and by the method of time–temperature curves over а temperature range – 35–180 оС. There is an eutectic equilibrium at –32.6 оС in the system; the solid phases of this equilibrium are ice and individual potassium thiocyanate. The composition of the liquid phase of the eutectic state was determined.

Processing of Reaction Masses of Lewisite in Arsenic-сontain Commercial Products

Authors: Demakhin A. G., Akchurin S. V.

The article presents the results of the development of technical decisions of processing of products detoxification lewisite in the arsenic oxide (III). Shows a general scheme and the basic process steps of this process. Particular attention is paid to the method of removal of arsenic (V) from the system, which can contaminate the final product. 

Sorbents Based on Natural Bentonites Modified with Iron (III) and Aluminum Polyhydroxocations by the Sol-Gel Method

Authors: Komov D. N., Kazarinov I. А., Nikitina N. V.

Natural bentonite was modified with iron (III) and aluminum polyhy- droxocations by the sol–gel technique. This modification of natural bentonite has been found to cause changes in its chemical composi- tion, structural and sorption properties. The modified sorbents are fine-porous (nanostructured) objects with the predominance of 1.5–6.0 nm pore size. The specific surface area of our sorbents depends on the method of modification and the amount of the modifying component introduced (iron (III) or aluminum). The sorption capacity of the sorbents for permanganate anions was studied.

To the Question the Choice of a Derivatizing Agent for the Transfer of Methylphosphonic Acid and its O-alkils Ethers to Chromatographic Derivatives

Authors: Kuzmina R. I., Uglanova V. Z., Denisov S. N., Denisov N. S.

The products of the derivatization of methylphosphonic acid and its ethers were investigated by gas chromatography – mass spectrometry. The optimum conditions of the derivatization of higher-boiling organo- phosphorus compounds were described.

Determination of Pesticide Residues in Grapes and Tomatoes by High Resolution Mass-spectrometry

Authors: Amelin V. G., Andoralov A. M.

A method for determining the 20 pesticides (azoxystrobin, boscalid, chlorpyrifos, cyprodinil, diazinon, dimethoate, fluazifop-P-butyl, malathion, metribuzin, penconazole, phosalone, pirimicarb, piri- miphos-methyl, prometryn, propargite, pyraclostrobin, pyrimethanil, triadimenol, triadimefon, trifloxystrobin) in grapes and tomatoes by high performance liquid chromatography with tandem quadrupole – time of flight mass spectrometry detector (HPLC-MS / TOF), using sample preparation QuEChERS.

Effect of Temperature, Isotopic Composition of Water and Ethanol on the Tautomeric Equilibrium of Sulphonated Phenylazonaphtholes

Authors: Al-Saidi M. Z., Shtykov S. N.

The effect of temperature, isotopic composition of water and ethanol on the tautomeric equilib- rium of two phenylazonaphtholes that differ by sulphonic group in benzene ring was investigated spectrophotometrically. It was established that enhancement of water structure under decrease of temperature or change of common water to heavy one shifts the azoquinonhydrazone tautomeric equilibrium to more polar hydrazone tautomer. The destruction of water structure and decrease of solvent polarity at ethanol addition, on the contrary, increases the concentration of azotautomer.

Modeling of Adiabatic Potential Parameters for Monosubstituted Benzenes, Pyridines, Pyrones and Thiopyrones

Authors: Pankratov A. N.

By means of the Density Functional Theory DFT (B3LYP) method, quantum chemical computations of fundamental vibrations spectra of monosubstituted benzenes, pyridines, pyrones and thiopyrones have been carried out. The possibility of the aforesaid method application for the studied series of compounds vibrational spectra prediction have been substantiated.

Fragmentation Canals of Molecular Ions of GC-MS-Registered Components of Media of Shiitake Basidiomycete Submerged Cultivation in the Presence of Diacetophenonylselenide. Isomerization of Dihydrofurans and Their Cation Radicals

Authors: Pankratov A. N., Tsivileva O. M., Tsymbal O. A., Yurasov N. A.

The molecular ions fragmentation canals of substances registered by means of the GC-MS method in the media of Lentinula edodes (shiitake) basidiomycete submerged cultivation in the presence of diacetophenonylselenide have been substantiated. At the B3LYP/6-311++G(3df,3pd) and UB3LYP/6-311++G(3df,3pd) level, involving the NBO analysis and the R. F. W. Bader’s «Atoms in Molecules» quantum theory (QTAIM), isomeric transformations of dihydrofurans have been considered.

The Peculiarities of Synthesis of Acid Esters of Methylphosphonic Acid

Authors: Denisov N. S., Tumskiy R. S.

The peculiarities of synthesis of acid esters of methylphosphonic acid for further use in the system of chemical and analytical control of the environment have been discovered.

Mass Fraction Evaluation of the Basic Substance in Dialkyl Methylphosphonate Samples by Potentiometric Titration

Authors: Uglanova V. Z., Denisov N. S.

A technique for the mass fraction evaluation of the basic substance in dialkyl methylphosphonate samples by automatic potentiometric titration is presented. A comparison was made with a certified technique of visual titration. Several advantages of our method are shown: the ability to automate analysis, a reduced sample weight, a constant and precise volume of a titrant drop, a reduced detection time, avoiding the use of chemical indicators, an improved precision of analysis.

Determination of the Contents of Arsenic, Mercury, Copper, Nickel and Zinc in the Soil and Ventilating Emissions by Method of Atomic Absorption Spectrometry (AAS)

Authors: Demakhin A. G., Akchurin S. V.

The method of atomic absorbing spectrometry (AAS) determined the content of mobile forms of copper, nickel and zinc, and total content of mercury and arsenic in the soil samples selected in a residential zone Samara, and copper in the ventilating emissions. For soils the sample preparation stage contribution to the general error of analytical definition is estimated. For ensuring correctness definition of the content of copper in the ventilating emissions the correction coefficient cons idering existence of a systematic mistake is calculated.

Determination of the Contents of Arsenic, Mercury, Copper, Nickel and Zinc in the Soil and Ventilating Emissions by Method of Atomic Absorption Spectrometry (AAS)

Authors: Lobachev А. L.

The method of atomic absorbing spectrometry (AAS) determined the content of mobile forms of copper, nickel and zinc, and total content of mercury and arsenic in the soil samples selected in a residential zone Samara, and copper in the ventilating emissions. For soils the sample preparation stage contribution to the general error of analytical definition is estimated. For ensuring correctness definition of the content of copper in the ventilating emissions the correction coefficient considering existence of a systematic mistake is calculated.

Synthesis and Luminescence Studies of Terbium Complex with 2,6-dibenzylidenecyclohexanone

Authors: Pozharov M. V., Zakharova T. V.

Novel complex of terbium (III) with aromatic monoketone – 2,6-dibenzylidenecyclohexanone – has been synthesized. Its uncharacteristic luminescent properties have been studied using quantum chemical calculations and lumiscent spectroscopy.

Synthesis of Monodisperse Magnetite: The Effect of Temperature, Sodium Hydroxide and Citric Acid Concentrations on the Size of Nanoparticles

Authors: Egunova O. R., German S. V., Shtykov S. N., Vrabie Y. A.

The effect of temperature, sodium hydroxide and citric acid concentrations on the size of magnetic magnetite nanoparticles was studied. Optimal conditions for synthesis of magnetite stabilized by citric acid with narrow size distribution were found. The average size of the nanoparticles determined by dynamic light scattering and transmission electron microscopy 12 ± 3 and 6 ± 2 nm, respectively was established. The chemical composition and structure of magnetite nanoparticles was confirmed by X-ray diffraction method.

Selective Determination of Histidine in Mixed Solutions of α-Amino Acids

Authors: Chernova R. K., Varygina O. V., Bereskina N. S.

Examined the condition of the main and neutral α-amino acids in aqueous media. Graphs of the distribution of ionized forms of histidine and alanine with varying pH. Pakistan the possibility of pH –metric selective determination of histidine in mixtures of neutral amino acid with a glass indicator electrode. The error does not exceed 7%

Viscous Degradation of Acidic Chitosan Solutions and its Ionic Probe Study

Authors: Boyko I. S., Podkolodnaya O. A., Lysachok S. G., Shmakov S. L.

A review of the literature on the phenomenon of aging (a significant drop in viscosity over time) of acidic chitosan solutions is given. A study was made on acetic acid (2%) solutions of chitosan of two viscosity-average molecular weights (200 and 46 kDa) by ion probing (addition of a KI solution). It has been indirectly confirmed that the motion of the probing ions in an electric field disturbs part (about a quarter) of the average macromolecule rather than the whole one.

Ethanol Conversion on Zeolites

Authors: Kuzmina R. I., Pilipenko A. Y., Khoroshilov I. I., Frolov M. P.

The possibility of converting the biomass to products of petrochemical synthesis is shown. The analysis of the development of the synthesis of catalysts for production of motor fuels from bioethanol is carried out. By varying the composition of the catalysts and the process conditions can be synthesized gasoline range hydrocarbons, ethylene, aromatic hydrocarbons. A scheme for the conversion of ethanol to hydrocarbons of various classes is discussed.

Reaggregation Positional Isomers Tetrazologeksahidroquinazoline

Authors: Vasilkova N. O., Borisova M. Y., Yurasov N. A., Krivenko A. P.

9-phenyl-4,5,6,7,8,9-geksagidrotetrazolo[5,1-b]quinazoline in solution undergoes reaggregation ent via an azide to form a positional isomer corner structure that is installed involving spectral methods (1H-NMR, IR -spectra), TLC, chromato-mass spectrometry.

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