Prospects in Analytical Atomic Spectrometry

Tendencies in five main branches of atomic spectrometry (absorption, emission, mass, fluorescence and ionization spectrometry) are considered. The first three techniques are the most widespread and universal, with the best sensitivity attributed to atomic mass spectrometry. In the direct elemental analysis of solid samples, the leading roles are now conquered by laser-induced breakdown and laser ablation mass spectrometry, and the related techniques with transfer of the laser ablation products into inductively-coupled plasma. Advances in design of diode lasers and optical parametric oscillators promote developments in fluorescence and ionization spectrometry and also in absorption techniques where uses of optical cavities for increased effective absorption pathlength are expected to expand. Prospects for analytical instrumentation are seen in higher productivity, portability, miniaturization, incorporation of advanced software, automated sample preparation and transition to the multifunctional modular architecture. Steady progress and growth in applications of plasma- and laser-based methods are observed. An interest towards the absolute (standardless) analysis has revived, particularly in the emission spectrometry.Comment: Proofread copy with an added full reference list of 279 citations. A pdf version of the final published review may be requested from Alexander Bol'shakov <[email protected]

MAGNETIC SURFACE-MODIFIED NANOSIZED SORBENT FOR MSPE-HPLC-UV DETERMINATION IN NATURAL WATERS

In order to develop a more simple and efficient procedure of preconcentration and determination of the organic pollutants in waters it has been proposed to apply a static mode of magnetic solid-phase extraction using a novel surface-modified nanosized sorbent. The synthesis procedure of the sorbent consisted of: 1) synthesis of magnetite nanoparticles by co-precipitation method; 2) subsequent surface modification with tetraethoxysilane (TEOS) and cetyltrimethylammonium bromide (CTAB). Both stages were performed using microwave heating. The formation of nanoparticles was confirmed by SEM and dynamic light scattering method. The possible structure of the surface adsorption layer of the sorbent particles was characterized by comparing experimental and literature data on the CTAB adsorption. Sorption properties of the material have been investigated using 4-nonylphenol (4-NF) as an example. The extraction of 4-NF from aqueous solutions and surface waters with typical salt and dissolved organic matter content was shown to be quantitative. The technique based on the magnetic solid-phase extraction and HPLC determination of 4-NF has been developed.  The duration of a single analysis was about 35-40 min, detection limit – 2 µg/L of 4-NF.Keywords: magnetic nanoparticles, microwave synthesis, magnetic separation, 4-nonylphenol, HPLC, natural waters(Russian)DOI: http://dx.doi.org/10.15826/analitika.2015.19.3.006D.V. Pryazhnikov, M.S. Kiseleva, I.V. Kubrakova V.I. Vernadsky Institute of Geochemistry and Anaytical Chemistry, Russian Academy of Sciences, Moscow, Russian FederationIn order to develop a more simple and efficient procedure of preconcentration and determination of the organic pollutants in waters it has been proposed to apply a static mode of magnetic solid-phase extraction using a novel surface-modified nanosized sorbent. The synthesis procedure of the sorbent consisted of: 1) synthesis of magnetite nanoparticles by co-precipitation method; 2) subsequent surface modification with tetraethoxysilane (TEOS) and cetyltrimethylammonium bromide (CTAB). Both stages were performed using microwave heating. The formation of nanoparticles was confirmed by SEM and dynamic light scattering method. The possible structure of the surface adsorption layer of the sorbent particles was characterized by comparing experimental and literature data on the CTAB adsorption. Sorption properties of the material have been investigated using 4-nonylphenol (4-NF) as an example. The extraction of 4-NF from aqueous solutions and surface waters with typical salt and dissolved organic matter content was shown to be quantitative. The technique based on the magnetic solid-phase extraction and HPLC determination of 4-NF has been developed.  The duration of a single analysis was about 35-40 min, detection limit – 2 µg/L of 4-NF.Keywords: magnetic nanoparticles, microwave synthesis, magnetic separation, 4-nonylphenol, HPLC, natural waters DOI: http://dx.doi.org/10.15826/analitika.2015.19.3.00

Magnetic surface-modified nanosized sorbent for MSPE-HPLC-UV determination in natural waters

В целях разработки простой, быстрой и эффективной схемы аналитической пробоподготовки для определения в водных образцах органических загрязнителей нами был получен новый высокодисперсный сорбционный материал с магнитными свойствами (Fe₃O₄@SiO₂@СТАВ). Искомый сорбционный материал синтезировали путем микроволнового синтеза наночастиц магнетита и их последовательного модифицирования тетраэтоксисиланом и бромидом цетилтриметиламмония (СТАВ). Для образцов поверхностно-модифицированного материала были получены данные по размерам и форме частиц, знаку и величине заряда поверхности частиц. Также была охарактеризована структура поверхностного слоя, исходя из полученных данных по сорбции бромида цетилтриметиламмония. Исследована зависимость сорбционных свойств Fe₃O₄@SiO₂@СТАВ по отношению к 4-нонилфенолу (4-НФ) для двух образцов с различным количеством модификатора СТАВ на поверхности сорбента. На примере 4-НФ изучены сорбционные свойства Fe₃O₄@SiO₂@СТАВ, оптимизированы условия количественного извлечения 4-НФ (масса сорбента, объем раствора, рН раствора, время сорбции и десорбции) и разработана методика его определения в водных объектах, включающая стадию магнитной твердофазной экстракции, экстракцию 4-НФ ацетонитрилом и последующее ВЭЖХ-определение. На примере ряда модельных образцов вод с различным минеральным и органическим фоном показано незначительное влияние матричных компонентов на степень извлечения 4-НФ. Проведение единичного определения по предложенной методике занимает 35-40 минут, предел обнаружения 4-НФ ─ 2 мкг/л.In order to develop a more simple and efficient procedure of preconcentration and determination of the organic pollutants in waters it has been proposed to apply a static mode of magnetic solid-phase extraction using a novel surface-modified nanosized sorbent. The synthesis procedure of the sorbent consisted of: 1) synthesis of magnetite nanoparticles by co-precipitation method; 2) subsequent surface modification with tetraethoxysilane (TEOS) and cetyltrimethylammonium bromide (CTAB). Both stages were performed using microwave heating. The formation of nanoparticles was confirmed by SEM and dynamic light scattering method. The possible structure of the surface adsorption layer of the sorbent particles was characterized by comparing experimental and literature data on the CTAB adsorption. Sorption properties of the material have been investigated using 4-nonylphenol (4-NF) as an example. The extraction of 4-NF from aqueous solutions and surface waters with typical salt and dissolved organic matter content was shown to be quantitative. The technique based on the magnetic solid-phase extraction and HPLC determination of 4-NF has been developed. The duration of a single analysis was about 35-40 min, detection limit - 2 µg/L of 4-NF