V. P. Fadeeva

Elemental analysis of organic compounds with the use of automated CHNS analyzers

Results of many years’ worth of studies on the determination of carbon, hydrogen, and nitrogen on automated CHNS analyzers were summarized. Catalytic oxide compositions were selected that allow for the analysis of synthetic and natural organic compounds and materials of any elemental composition and structure: polycyclic, condensed aromatic, heterocyclic, carbonaceous (graphites and carbons), organometallic, organoelement, etc.

Analysis of humic acids from various soils using acid hydrolysis

Structural changes in humic acids from various soils, produced by acid hydrolysis, are studied by elemental and thermal analyses and by IR and NMR spectroscopy.

Determination of boron in organic compounds by microwave plasma–atomic emission spectrometry

We propose a method for the determination of boron in aliphatic and aromatic trifluoroborates (including perfluorinated ones), ethers, and organoboron compounds containing dioxoborolane fragments, pyridine, and pyrazole rings, and triple bonds. The substances were decomposed by the oxygen flask combustion method. Boron was determined on an Agilent 4100 microwave plasma–atomic emission spectrometer. A number of organic compounds were analyzed, and the mass fraction of boron was determined with an error less than ±0.3 abs. %.

Extraction-spectrophotometric determination of selenium in organoselenium compounds using aromatic o-diamines

Procedures for the extraction-spectrophotometric determination of selenium in organoselenium compounds using a new reagent, 1,2-diamino-3,4,5,6-tetrafluorobenzene (DAFB), and a known reagent, 2,3-diaminonaphthalene (DAN), are developed. Complexes of DAFB or DAN with selenium(IV) are extracted with toluene, and the absorbance of the extracts is measured. The optimal conditions for the determination were found, and the spectrophotometric characteristics were determined. The calibration curves are linear in the range of selenium concentrations of 1–10.6 mg/L (DAFB) and 1–9.1 mg/L (DAN). Nitrogen, chlorine, bromine, fluorine, and sulfur present in organoselenium compounds do not interfere with the determination of selenium. The relative error of determination does not exceed ±2%.

Study of the fragment composition of humic acids of different origin using IR-EXPERT software

Infrared spectra of humic acids have been studied using the IR-EXPERT computer system and database developed in the Novosibirsk Institute of Organic Chemistry. The information on the closest spectral analogues, their structures, and most probable structural fragments present in humic acid samples from Siberian peats and soils has been obtained.

Determination of organogenic elements in the composition of functional compounds and materials

The presented analysis methods (automatic and gravimetric) are used to determine the main composition of various organic functional materials such as paramagnetic chelating agents for the synthesis of molecular magnetics, polyfluoroaromatic compounds for the preparation of special latices, new antivirus and analgesic agents, photoinitiator compounds for cationic polymerization, fluorophores for organic light emitting diodes, and so on. Conditions for the quantitative formation of final products of the complete decomposition of the compound (CO2, H2O, N2, SO2) are shown: the application of special oxide catalytic compositions and also the use of selectively adsorbing reagents for the removal of compounds hindering the determination of organogenic elements. Their determination error does not exceed ±0.3 % abs.

NMR Study of Structural Changes in Humic Acids of Meadow Soddy Soils

Quantitative and qualitative changes in humic acids of meadow soddy soils, occurring under the action of various fertilizer systems, were studied by 13C and 31P NMR.

Elemental Content and Functional Group Analysis of Humic Acids in Fossilized Soils of Different Ages

A comparative study of elemental composition, thermal characteristics, and IR and NMR spectra of humic acids recovered from modern and fossilized soils was made. The results obtained allow reconstruction of trends in variation of the environmental conditions in the course of soil formation at lake depressions in the Khakassia over a period from 3400 to 850 years before present day.

Separation of pyrimidine derivatives by reversed-phase high-performance liquid chromatography

Chromatographic behavior and separation conditions of pyrimidine derivatives were studied by high-performance liquid chromatography using a reversed-phase column and a multiwave UV detector.

Separation of Multicomponent Mixture of Naphthalene Derivatives by Reversed-Phase High-Performance Liquid Chromatography

Separation of a mixture of naphthalene derivatives by reversed-phase high-performance liquid chromatography with UV detection was studied. Chromatographic characteristics were calculated for nine compounds, including naphthalene.