Preparation of crystalline Mg(OH)2 nanopowder from serpentinite mineral

In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array (Russia, Orenburg region). An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 C followed by NH4OH titration for Mg(OH)2 precipitation was demonstrate

ПРОТОЧНО-ИНЖЕКЦИОННОЕ ОПРЕДЕЛЕНИЕ ВАЛИНА ПЬЕЗОКВАРЦЕВЫМ СЕНСОРОМ, МОДИФИЦИРОВАННЫМ ПОЛИМЕРОМ С МОЛЕКУЛЯРНЫМИ ОТПЕЧАТКАМИ А.Н.Зяблов, С.И.Говорухин, О.В. Дуванова, В.Ф. Селеменев, Ань Тьен Нгуен

Flow-injection determination methods of analysis are gaining their popularity due to vast production of pure amino-acids and their quality control. This report describes methods of valine determination in aqueous solutions using a flow-injection system with piezoelectric sensor on the basis of molecular imprinted polymers (MIP) as a detector. To produce MIP polyamide acid was synthesized at 453 K directly on the surface of the sensor. The tamplate was removed without destruction of polymeric coating. Modified sensors MIP-Val were fit into a cell of original design. The speed of the eluent flow through the cell was 0.9 ml/min. The volume of the injected sample was 100 uL.The experimental part proved the ability of piezoelectric sensor modified with molecular imprinted polymer to determine valine in binary mixtures with glutamic acid. Detection limit of valine was 10-5 mol/L. The obtained data showed selectivity of piezoelectric sensor modified with (MIP) only to valine. Imprinting factor for the sensor modified with MIP-Val, IF =3.2Keywords: valine, glutamic acid, piezoelectric sensor, molecular imprinted polymers (MIPs), flowing-injection analysis. (Russian)DOI: http://dx.doi.org/10.15826/analitika.2014.18.4.010 *A.N. Zyablov, *S.I. Govorukhin, *O.V. Duvanova, *V.F. Selemenev, **Nguen An' T'en * Voronezh State University, Voronezh, Russian Federation**Ho Chi Minh City University of Pedagogy, Ho Chi Minh City, Viet Nam REFERENCES1. Kel'ner R., Merme Zh.-M., Otto M., Vidmer G.M. Analiticheskaia khimiia. Problemy i podkhody [Analytical Chemistry. Issues and Approaches], Moscow, Mir: AST, 2004. Vol. 1. 608 p. (in Russian).2. Evgen'ev M.I., Garmonov S.Iu., Shakirova L.Sh. [Flow injection analysis of drugs]. Zhurn. analit. khimii [J. of Anal. Chem], 2001, vol. 56, no. 4, pp. 355-366 (in Russian).3. Gendrikson O.D., Zherdev A.V., Dzantiev B.B. [Molecularly imprinted polymers and their use in the biological assay]. Uspekhi biologicheskoi khimii [Success of biological chemistry], 2006, vol. 46, pp. 149-192 (in Russian).4. Ziablov A.N., Kalach A.V., Zhibrova Iu.A., Selemenev V.F., D'iakonova O.V. [Determination glycine piezosensor aqueous solutions modified with a molecularly imprinted polymer]. Zhurn. analit. khimii [J. of Anal. Chem], 2010, vol. 65, no. 1, pp. 93-95 (in Russian).5. Zhibrova Iu.A., Ziablov A.N., Shcheglova N.A., Krasnikova O.P., Selemenev V.F. [Molecularly imprinted polymers for piezoelectric sensors Message 1. Analysis of pharmaceutical preparations containing glycine]. Sorbtsionnye i khromatograficheskie protsessy [Sorption and chromatographic processes], 2008, vol. 8, no. 4, pp. 686-688 (in Russian).6. Ziablov A. N., Monicheva T.S., Selemenev V.F. [Detection of amino acids in the preparation of "BCAA" piezoelectric sensor modified with molecularly imprinted polymers]. Analitika i kontrol' [Analitics and control], 2012, vol. 16, no. 4, pp. 406-409 (in Russian).7. Ziablov A.N., Nikitskaia L.M., Zhibrova Iu.A., Kalach A.V., Selemenev V.F. P'ezosensor na osnove polimerov s molekuliarnym otpechatkom aminokislot [Piezosensor based on Molecularly imprinted polymers of amino acids]. Patent RF. no 2010142819/28, 2011 (in Russian).8. Bykov V.A., Krylov I.A., Manakov M.N. Mikrobiologicheskoe proizvodstvo biologicheski aktivnykh veshchestv i preparatov [Microbiological production of bioactive substances and drugs]. Moscow, High school, 1987. 143 p. (in Russian).9. Cormack P. A. G., Elorza A. Z. [Molecularly imprinted polymers: synthesis and characterization]. Journal of Chromatography B, 2004, vol. 804, no. 1, pp. 173-182.10. Dmitrienko S.G., Irkha V.V., Kuznetsova L. Iu, Zolotov Iu. A. [Use of molecularly imprinted polymers in separation processes and concentration of organic compounds]. Zhurn. analit. khimii [J. of Anal. Chem.], 2004, vol. 59, no. 9, pp. 902-913.Предложен способ определения валина в водных растворах с применением проточно-инжекционной системы, имеющей в качестве детектора пьезоэлектрический сенсор на основе полимера с молекулярными отпечатками (ПМО-Val). Диапазон определяемых концентраций валина составляет 10–1–10–6 М, экспериментально установленный предел обнаружения - 10–5 М. Выявлены рабочие условия проточно-инжекционного определения валина в смесях с глутаминовой кислотой. Оценена способность пьезоэлектрического сенсора на основе полимера с молекулярными отпечатками к распознаванию валина в бинарных смесях с глутаминовой кислотой. Импринтинг-фактор для сенсора, модифицированного ПМО-Val, IF = 3.2. Рекомендуемый способ анализа характеризуется экспрессностью, небольшим расходом проб и реагентов, возможностью автоматизации измерений.Ключевые слова: валин, глутаминовая кислота, пьезоэлектрический сенсор, полимеры с молекулярными отпечатками, проточно-инжекционный анализ. DOI: http://dx.doi.org/10.15826/analitika.2014.18.4.010 ЛИТЕРАТУРА1.Аналитическая химия. Проблемы и подходы: в 2 т. / ред.: Р. Кельнер [и др.]; пер. с англ.: А.Г. Борзенко [и др.] под ред. Ю.А. Золотова. М.: Мир: АСТ, 2004. Т.1. 608 с.2. Евгеньев М.И., Гармонов С.Ю., Шакирова Л.Ш. Проточно-инжекционный анализ лекарственных веществ // Журн. аналит. химии. 2001. Т. 56, № 4. С. 355-366.3. Гендриксон О.Д., Жердев А.В., Дзантиев Б.Б. Молекулярно-импринтированные полимеры и их применение в биологическом анализе // Успехи биологической химии. 2006. Т. 46. С. 149-192.4. Определение глицина в водных растворах пьезосенсором, модифицированным полимером с молекулярным отпечатком / А.Н. Зяблов [и др.] // Журн. аналит. химии. 2010. Т. 65, № 1. С. 93-95.5. Полимеры с молекулярными отпечатками для пьезокварцевых сенсоров Сообщение 1. Анализ лекарственных препаратов, содержащих глицин / Ю.А. Жиброва [и др.] // Сорбционные и хроматографические процессы. 2008. Т. 8, Вып. 4. С. 686-688.6. Зяблов А. Н., Моничева Т.С., Селеменев В.Ф. Детектирование аминокислот в препарате "ВСАА" пьезокварцевыми сенсорами, модифицированными полимерами с молекулярными отпечатками // Аналитика и контроль. 2012. Т. 16, № 4. С. 406-409.7. Пат. 102264 Российская Федерация, МПК(51) G01N27/12. Пьезосенсор на основе полимеров с молекулярным отпечатком аминокислот / А.Н. Зяблов [и др.] (РФ). № 2010142819/28; заявл. 19.10.2010; опубл. 20.02.2011, Бюл. № 5. 5 с. 8. Микробиологическое производство биологически активных веществ и препаратов / В.А. Быков [и др]. М.: Высш. шк., 1987. 143 с.9. Molecularly imprinted polymers: synthesis and characterization / Cormack P.A.G., Elorza A.Z. // Journal of Chromatography B. 2004. V. 804, № 1. P. 173-182.10. Использование полимеров с молекулярными отпечатками в процессах разделения и концентрирования органических соединений / С.Г. Дмитриенко [и др.] // Журн. аналит. химии. 2004. Т. 59, № 9. С. 902-913.

Microstructural and physical properties of magnesium oxide-doped silicon nitride ceramics

Silicon nitride based ceramics with aluminum, yttrium and magnesium oxides were produced by cold isostatic pressing and free sintering. The phase composition of the starting MgO powder obtained by the novel technology has been studied. The effect of magnesium oxide content on the structure of the produced materials has been investigated. It was found, that obtained materials with 1 and 2 wt.% of magnesium oxide and without it have a typical β-silicon nitride structure with elongated grains. Ceramics with 5 wt.% magnesia has a duplex α/β-structure with elongated and equiaxed grains. Ceramics with 2 wt.% magnesium oxide has a maximum density of 2.91 g/cm3. The increases in magnesium oxide content upto 5% led to decrease in the shrinkage (from 16% to 12%) and density (from 2.88 to 2.37 g/cm3). Keywords: Silicon nitride, Magnesium oxide, Structur

Preparation of crystalline Mg(OH)2 nanopowder from serpentinite mineral

In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array (Russia, Orenburg region). An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 °C followed by NH4OH titration for Mg(OH)2 precipitation was demonstrated. In this study, crystalline Mg(OH)2 nanopowders have been synthesized by solvothermal reaction method using (Mg(NO3)2⋅6H2O) which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray phase analysis (XRD), and inductively coupled plasma optical emission spectroscopy (ICP-OES). XRD reveals that Mg(OH)2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg(OH)2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg(OH)2 are 30–265 nm length or width. Keywords: Serpentinite, Nitric acid leaching, Magnesium hydroxide, Solvothermal reaction method, Crystalline Mg(OH)2 nanopowde

Synthesis of Magnesium Oxide Nanopowder by Thermal Plasma Using Magnesium Nitrate Hexahydrate

Magnesium oxide (MgO) nanopowder was synthesized by thermal plasma in a novel thermal DC plasma torch using magnesium nitrate hexahydrate. Magnesium nitrate hexahydrate (Mg(NO3)2·6H2O) was obtained from serpentinite (Mg3Si2O5(OH)4; lizardite) (Halilovskiy array, Orenburg region, Russia). The synthesized samples were characterized by analytical techniques including X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM characterization studies confirmed that MgO nanopowder obtained has periclase structure with high purity, and the particle sizes vary within the range of 100 nm to 150 nm. We believe that the present work will promote further experimental studies on the physical properties and the applications of MgO nanopowders in the fields such as high-densed ceramics, additives in bactericide, and refractory products

Research of micro and nano profile surface morphology of vibrational mechanical and chemical zinc coating

There are some results of zinc coating research acquired on the metals’ surface as a result of mechanical and chemical synthesis, realized in conditions of vibro wave technological systems. The peculiarities of the surface morphology at the micro / nano level of the zinc coating are shown which are formed under the influence of low-frequency oscillations. The growth interconnection of the micro / nano profile of the applied zinc coating is shown. The determination of changes occurring on the coating layer surface at the micro / nano level. The absence of reliable data of the surface layer of the coating at the nano level has significantly limited its modification background. All of the mentioned above brings up to the following task, the given article is devoted to its solution: establishment of particlesdimension, the way of their distribution on the metal surface, besidestheir maximal and minimal roughness data cause by the alteration of the processing time

Research of micro and nano profile surface morphology of vibrational mechanical and chemical zinc coating

There are some results of zinc coating research acquired on the metals’ surface as a result of mechanical and chemical synthesis, realized in conditions of vibro wave technological systems. The peculiarities of the surface morphology at the micro / nano level of the zinc coating are shown which are formed under the influence of low-frequency oscillations. The growth interconnection of the micro / nano profile of the applied zinc coating is shown. The determination of changes occurring on the coating layer surface at the micro / nano level. The absence of reliable data of the surface layer of the coating at the nano level has significantly limited its modification background. All of the mentioned above brings up to the following task, the given article is devoted to its solution: establishment of particlesdimension, the way of their distribution on the metal surface, besidestheir maximal and minimal roughness data cause by the alteration of the processing time

The application of microphotographic method of registration of the swelling effect of sorption-active polymer granules for the analysis of biologically active substances solutions

Предложен микрофотографический способ анализа растворов биологически активных веществ на основании интегральной зависимости степени набухания в них нескольких сорбционно-активных полимерных гранул. В качестве единичного аналитического сигнала использован полученный с применением цифрового фотоаппарата, совмещенного с микроскопом, цифровой видеосигнал, регистрирующий степень набухания гранулы полимера. В качестве интегрального показателя предложено использовать геометрические параметры диаграмм, построенных в полярных координатах, на которых отложены результаты измерений объемов нескольких набухающих гранул.Proposed microphotographic method of analysis for the analysis of solutions of biologically active substances on the basis of integral dependence of the degree of swelling of several sorption-active polymer granules in the analyzed solution. As a single analytical signal is used a digital video which is obtained using a digital camera combined with a microscope and which allows to record the degree of swelling of the polymer granules. To evaluate the generalized result of a multisensory analysis is proposed to use the geometrical parameters of diagrams constructed in polar coordinates

Detection of aminoacids in preparation «BCAA» piezoquartz sensors, modified molecular imprinting polymers

Предложено определение аминокислот валина, лейцина и изолейцина в водных растворах и в препарате «ВСАА» пьезосенсорами, модифицированными полимерами с молекулярными отпечатками. Оценена способность модифицированных пьезокварцевых сенсоров к распознаванию аминокислот в препарате.A definition of aminoacids valine, leucine and isoleucine in aqueous solutions and in the preparation «BCAA» piezosensors, modified polymers with molecular imprints is offered. The ability of the modified piezoquartz sensors to reorganization of aminoacids in the preparation is appreciated