Chemistry

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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