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41.
D. A. Dobrokhotov A. N. Kuz’menko O. V. Nesterova V. Yu. Reshetnyak V. A. Popkov E. B. Pashkova A. V. Pirogov 《Moscow University Chemistry Bulletin》2011,66(2):125-128
The methods of gas-liquid chromatography and mass-selective detection were used to determine the composition of the volatile
fraction of plant extracts included in herb mixtures used for treating parodontal disease. The following marker substances
were found: naphthalene derivatives for pot marigold, furan derivatives for trifid bur-marigold and burnet, and the specific
terpenoids for licorice, milfoil, and wild marjoram. All the plants used in the herb mixture, except for pot marigold and
cinquefoil, were analyzed (ion-exclusion chromatography) for the content of lower carboxylic acids. It was established that
the specific acids for the wild marjoram and licorice are ascorbic and the succinic acids, respectively. 相似文献
42.
E. B. Pashkova A. V. Pirogov D. V. Yunovidov O. A. Shpigun 《Moscow University Chemistry Bulletin》2011,66(1):38-42
A technique for the quantitative determination of capsaicin in liniments by the microemulsion liquid chromatography method
is proposed. Due to the absence of the homogenization, extraction and filtration stages, the procedure of sample pretreatment
takes 5 minutes, which is much more rapid in comparison with the variants described in the literature (from 30 minutes to
12 hours). The full time of the analysis (including the procedure for sample pretreatment) is 20 minutes. The graduation curve
is linear in the range from 0.02 to 240 mg/l. The limit of determination of capsaicin was 8 μg/I. 相似文献
43.
M. S. Gruzdev N. E. Domracheva A. I. Aleksandrov V. P. Osipova U. V. Chervonova A. M. Kolker T. V. Pashkova D. V. Barakhtenko 《Journal of Structural Chemistry》2012,53(6):1062-1074
An iron(III)-containing complex with the asymmetric tridentate azomethine ligand 4,4′-dodecyloxybenzoyloxybenzoyl-4-salicylidene-N′-ethyl-N-ethylenediamine with a PF 6 ? counterion is obtained. The presence of the complexing ion is confirmed by far IR Fourier spectra. The structure of the compounds is determined by matrix-assisted laser desorption/ionization with a time-of-flight mass analyzer (MALDI-ToF). The results of mass spectrometric studies are consistent with the elemental analysis data. It is found that the complexation of iron salt with an asymmetric tridentate ligand results in the formation of compounds of the composition 1:1 with octahedral packing of a metal ion in the complex. The electrochemical behavior of the compound in organic solvents is examined. The EPR study shows that iron(III) ions are in both low spin (LS) and high spin (HS) states in the complex. The LS and HS iron(III) centers are coupled into dimers in which a water molecule and the PF 6 ? counterion act as bridges. It is also found that for LS complexes in the lowtemperature phase (4.2–300 K), the (d xz ,d yz )4(d xy )1 electronic state is the ground state. It is revealed that the conversion of the sample into a high-temperature liquid crystalline (387–405 K) phase is accompanied by the conversion of the LS states of the Fe(III) ion: (d xz ,d yz )4(d xy )1 ? (d xy )2(d xz ,d yz )3. The conversion of LS states is temperature reversible and is driven by the temperature. X-ray crystallographic data confirm that the compound obtained consists of dimer formed by a hydrogen (O-H...F) bond. 相似文献