Head of the laboratory of chemistry for organo-mineral materials
Department of analytical chemistry Taras Shevchenko
National University of Kyiv
60 Vladimirskaya Str., Kiev Ukraine 01601
D.Sc., PhD, Corr. member of Acad. of Sci. of Ukraine
Sorption of Heteropoly Acids on Cellulose Sorbents (in Russian).
Chem. Phys. Technol. Surf. 3(1), 66–73 (2012)
http://www.cpts.com.ua/images/stories/pdf/3/3.1/zuy.pdf
Sorption
of heteropoly acids on the surfaces of cellulose and
diethylaminoethylcellulose with molybdovanadophosphoric acid as an example
has been studied by UV-VIS, infrared, and MAS-NMR spectroscopy. It has been
shown that sorption of heteropoly acid on diethylaminoethylcellulose is
substantially higher than that on ordinary cellulose. The mechanism of
sorption includes combination of Coulomb and hydrophobic interactions. A
scheme of heteropoly acids immobilization has been proposed based on ion
exchange on cellulose surface.
Electrophoretically deposited carbon nanotubes as a novel support for electrogenerated silica–dehydrogenase bioelectrodes.
Electrochimica Acta 83 (2012) 359– 366
The
electrophoretic deposition of carbon nanotubes (CNT) on glassy carbon
electrode was used here for the development of porous matrix with enhanced
electroactive surface area. The prepared layer displayed a catalytic
activity toward NADH oxidation and was used as a support for the d-sorbitol
dehydrogenase immobilization. The electrochemically assisted deposition
(EAD) method was performed to generate around carbon nanotubes sol–gel
biocomposite films containing the enzyme and a cationic polyelectrolyte.
The response of the immobilized enzyme strongly depended on the parameters
of sol–gel deposition as well as the thickness of carbon nanotubes layer.
The electrocatalytic oxidation of d-sorbitol using such modified electrode
was used here as a model to discuss the interest of such silica–carbon
nanotubes composite in the field of bioelectrochemistry and biosensors.
Speciation of partly oxidized thiol-organosilica surface.
Методы и объекты химического анализа (METHODS AND OBJECTS OF CHEMICAL ANALYSIS), 2012, т.7, № 2, с. 60-67
(http://www.moca.net.ua/12/pdf/60-67_2-7-2012.pdf)
The paper describes conductometric quantitative determination of thiol- and sulfonic acid groups on organosilica surface with immobilized layer of partly-oxidized mercaptopropyl groups. A set of MCM-41 type samples containing 1 mmol g-1 of mercaptopropyl groups was oxidized with proportional quantitates of hydrogen peroxide and subsequently was characterized with different ratio of grafted mercaptopropyl and propylsulfonic acid groups. The data calculated from conductometric titration were approved by collation with corresponding XPS spectra, which demonstrate linear correlation of results of both technique. The described method was applied to reveal ambient oxidation of organo-silicas with immobilized thiol groups.
ОСОБЛИВОСТІ РОЗДІЛЕННЯ ТРИМЕБУТИНУ ТА ПАРАБЕНІВ МЕТОДОМ РІДИННОЇ ХРОМАТОГРАФІЇ З ВИКОРИСТАННЯМ НЕРУХОМИХ ФАЗ РІЗНОЇ СЕЛЕКТИВНОСТІ
Журнал Хроматографічного товариства 2012, т.7 №1-4, с.4-12
В статье рассмотрено поведение соединений разной химической природы (тримебутин, метилпарабен, пропилпарабен, галловая кислота, 4-гидроксибензойная кислота) в зависимости от рН подвижной фазы на колонках разной селективности (С18, фенильная, пентафторфенильная ) Показано, что фактор удерживания тримебутина, существенно возрастает при увеличении значения рН от 2,1 до 6,8. Для С18 колонки фактор удерживания возрастает от 0,6 до 19,0. Фактор удерживания тримебутина в меньшей степени увеличивается для пентафторфенильной колонки от 0,2 до 6,8. Следовательно, пентафторфенильная колонка менее чувствительна к изменению рН, что делает такие колонки перспективными при разработке методик, как альтернативных к С18-фазе, за счет большей робастности разработанных методик.
Ключевые слова: тримебутин, парабены, жидкостная хроматография, фенильная колонка, пентафторфенильная колонка.
SYROTCHUK O.A., DIDUKH I.R., ZAITSEV V.M.
Separation of Trimebutin and Parabens by liquid chromatography on stationary
phases with different selectivity.
Zhurnal Khromatohrafichnoho tovarystva, 2012, v.12, No.1-4, p 4-12
The article is about chromatografic behavior of the compounds of different
chemical nature (trimebutine, methylparaben, propylparaben, gallic acid,
4-hydroxy benzoic acid) depending on pH of the mobile phases used on
chromatographic columns of different selectivity (C18, phenyl, pentafluorophenyl).
It has been shown that retention factor of trimebutine, increases dramatically
if pH chahges from 2.1 to 6.8. Retention factor increases from 0.6 to 19.0 for
C18-column. Retention factor increases less (from 0.2 to 6.8) when
pentafluorophenyl column is used. Hence, pentafluorophenyl column is less
sensitive to pH changes. So, it makes methods developed using this column more
robust.
Keywords: trimebutine, parabens, HPLC, phenyl-column, pentafluorophenyl-column
updated 01-dez-15
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Head of the laboratory of chemistry for organo-mineral materials Department of analytical chemistry Taras Shevchenko
National University of Kyiv |
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| tel: +380-97-0980693, e-mail: vnzaitsev@gmail.com, http://anchem.knu.ua/ua/main_ukr.html | |
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