The emerging technologies based on magnetic levitation and 3D printing manufacturing were utilized to create a sorbent retention platform as an alternative to traditional packed columns. The magnetic nanoscale sorbent was suspended in the aqueous solution in a 3D printed sorption cell placed between two permanent magnets. Simulations of hydrodynamic fluid and magnetic field were carried out to optimize the configuration and positioning of the sorption cell. The developed platform ensures uniform distribution of the sorbent in the cell’s volume and retention under dynamic conditions. The efficiency of palladium solid-phase extraction in a flow mode was demonstrated using modified magnetite nanoparticles. A high concentration factor can be achieved using the spiral shape of the cell with 50–100 mg of the suspended sorbent. The results of the spectrometric determination of trace amounts of palladium in natural water are given. An automated system for environmental analysis based on the proposed platform is promising.

The current trend in the development of separation methodologies implies their evolution in an environmentally friendly perspective, more precisely, the transition to techniques, materials, and solvents that could be qualified as greener alternatives to conventional ones. The green extraction systems can be attributed to aqueous biphasic systems, ionic liquids, and deep eutectic solvents, which have been widely used recently for various analytical, synthetic, and industrial tasks. In this chapter, the features of the listed systems are discussed in relation to the extraction of precious metals, mainly platinum, palladium, and gold; the examples of the alternative extraction systems for separation and preconcentration of precious metals are reviewed.

In the presented work, a new original procedure for the interfacial synthesis of the magnetic nanoparticles (MNPs) modified with a polymer shell and functionalized by an ionic liquid or a deep eutectic solvent in aqueous biphasic systems (ABSs) is proposed. The synthesis is carried out at the interface of immiscible liquids based on aqueous solutions of polyethylene glycol and inorganic salts. The advantages of the ABSs are biocompatibility, availability, and the high solvating properties of the components, which leads to control the composition and size of the prepared MNPs. The synthesis of the Fe3O4@PEG, Fe3O4@PEG@Cyphos IL 101, and Fe3O4@PEG@TOPO/butanol MNPs has been provided for biomedical and analytical applications. The morphology and structure of MNPs have been characterized by scanning and transmission electron microscopy, thermogravimetry, X-ray diffraction, and FT-IR spectroscopy. The average diameter of the MNPs is 12–14 nm with a narrow size distribution. Their superparamagnetic nature has been described using magnetometry. The synthesis parameters have been optimized and statistically analyzed using response surface methodology. The developed approach of interfacial synthesis can be potentially scaled up and/or be used to obtain nanoparticles of various composition and application.

The development of environmentally friendly methods of analytical chemistry has been one of the dominant areas of scientific research in recent decades. Environmental performance indices have become a valuable tool for assessing and quantifying the environmental impact of performing chemical analysis. This review article considers the main environmental indices presented in the literature, including aspects such as the safety of used chemical reagents, analytical performance, energy consumption, and waste generation. The review reflects recent advances in green indices and their potential role in a transition to greener and more sustainable analytical practices.

The development of environmentally safe methods of analytical chemistry has been one of the dominant directions of scientific research in recent decades. Ecological indexes have become a valuable tool for assessing and quantitatively determining the impact of conducting chemical analysis on the environment. This review article discusses the main ecological indexes presented in the literature, including aspects such as the safety of chemical reagents used, analysis productivity, energy consumption, and waste generation. The review reflects the latest achievements in the field of “green” indexes and their potential role in transitioning to more ecological and sustainable analytical methods.

A novel analytical procedure for the determination of gold by electrothermal atomic absorption spectrometry combined with selective liquid–liquid extraction by natural deep eutectic solvents (NADESs) is presented. The extraction ability of the NADESs prepared using menthol, thymol and camphor toward gold in hydrochloric acid solutions was studied. The extraction efficiency was improved by optimizing the parameters including the composition of the NADESs, the volume ratio of organic and aqueous phases, kinetics, and acidity of the solution. Quantitative determination of gold was carried out by electrothermal atomic absorption spectrometry directly in the NADESs phase dissolved in isopropyl alcohol. The extraction recovery of gold from 1 mol/L HCl with the NADESs based on menthol and camphor mixed in a molar ratio 1:1 was 99.7

A new technique for selective separation and enrichment of platinum group metals (platinum, palladium, rhodium, iridium, ruthenium) from model hydrochloric and chloride media into hydrophobic deep eutectic solvents without the use of chelating agents is presented for the first time. The process consists in extraction of precious metals into an eutectic solvent based on tetraoctylammonium bromide and a carboxylic acid with further re-extraction of metals with ammonium hydroxide and nitric acid solutions. The extraction efficiency of metals from 0.1 M HCl was > 99.7 % for Pt and Pd; 87.3 % for Ru; 45.1 % for Ir; 28.5 % for Rh using the tetraoctylammonium bromide/hexanoic acid eutectic solvent. The developed technique was applied for the separation of platinum and palladium from refinery wastewater to obtain individual fractions with purity of > 99.9 %. The procedure does not involve the use of toxic, volatile or flammable solvents and can be an environmentally benign alternative to traditionally used approaches.

The recovery and separation of Pd(II) and Pt(IV) from model solutions with high Cl– concentration ( 300 g L–1) were studied. The behavior of Pd(II), Pt(IV), and matrix components was examined in relation to the model solution acidity, Cl– concentration, and kind of extractants and stripping agents. The mechanisms of the extraction of platinum metals with various extractants (trioctylamine, methyltrialkylammonium chloride, tri-n-octylphosphine oxide, dibutyl sulfoxide, tributyl phosphate) from chloride solutions are described. A quaternary ammonium salt, methyltrialkylammonium chloride, is suggested for simultaneous quantitative recovery of Pd(II) and Pt(IV) from solutions with the acidity varying in a wide range and with high Cl– concentrations. The subsequent selective separation of the platinum metals from the organic phase occurs in the course of stripping with a 0.3 М NH4OH + 0.1 M NH4Cl solution. The composition of scrubbing solutions allowing separation of matrix components such as Fe(III), Te(IV), Cu(II), Pb(II), and partially Se(IV) from Pd(II) and Pt(IV) and regeneration of the extractant after the extraction and stripping was chosen. The efficiency of the recovery of Pd(II) and Pt(IV), the number of stripping steps, and the purity and yield of the individual fractions depend mainly on the solution acidity and Cl– concentration.

A new technique for selective separation and preconcentration of gold and platinum group metals (platinum, palladium, rhodium, iridium, ruthenium) from model chloride media into hydrophobic deep eutectic solvents without the use of any chelating agents have been presented for the first time. The technique consists in extraction of precious metals into an eutectic solvent based on tetraoctylammonium bromide (TOAB) and carboxylic acid. The extraction efficiency of metals from model technological solution in 0.1 M HCl in the presence of 100 g/L NaCl were 99.7-100% for Au, Pt and Pd; 91.8% for Ru; 54.1% for Ir; 45.3% for Rh using the TOAB/Hexanoic acid eutectic solvent. The procedure does not involve the use of toxic, volatile or flammable solvents and can be a «green» alternative to traditionally used approaches.

Показаны сравнительные возможности сорбционного и экстракционного выделения благородных металлов из солянокислых растворов с использованием анионообменного сорбента DIAION UBA 120 и экстрагента триоктиламина с азотсодержащими функциональными группами. Подобраны условия количественного селективного выделения палладия, платины и золота из модельных сбросных растворов, содержащих макроколичества меди, никеля, железа, свинца, селена, теллура, а также хлорид-иона до 200 г / л.

Fe3O4@PEG have been proposed for sorption of L-lysine-alpha-oxidase (LO) from the culture fluid of Trichoderma harzianum Rifai F-180 for the first time. To synthesize the Fe3O4@PEG nanoparticles, an original method based on aqueous biphasic systems has been developed. The PEG-modified magnetite provide a high sorption ability towards LO in contrast to the non-modified Fe3O4 synthesized by the traditional precipitation method. The morphology and structure of the prepared nanoparticles were characterized by TEM, FTIR and XRD. The data on magnetic properties and stability in physiological media are presented. The synthesized nanoparticles ensure quantitative sorption and desorption of LO during at least 3 cycles.

Министерство науки и высшего образования Российской Федерации Российская академия наук Научный совет по неорганической химии РАН Научный совет по аналитической химии РАН Научный совет по химической технологии РАН Российское химическое общество имени Д.И

Министерство науки и высшего образования Российской Федерации Российская академия наук Научный совет по неорганической химии РАН Научный совет по аналитической химии РАН Научный совет по химической технологии РАН Российское химическое общество имени Д.И

Министерство науки и высшего образования Российской Федерации Российская академия наук Научный совет по неорганической химии РАН Научный совет по аналитической химии РАН Научный совет по химической технологии РАН Российское химическое общество имени Д.И

Министерство науки и высшего образования Российской Федерации Российская академия наук Научный совет по неорганической химии РАН Научный совет по аналитической химии РАН Научный совет по химической технологии РАН Российское химическое общество имени Д.И

The review is devoted to the analysis of published data on the synthesis and use of magnetic nanoparticles modified by ionic liquids for the separation and determination of various substances in environmental samples. The main attention is paid to the determination of organic pollutants in natural waters, soils, etc. The main trends in the development of magnetic solid-phase extraction methods are noted. Methods for the synthesis of magnetic nanoparticles promising for creating new methods of sample preparation are considered.

Сочетание современных методов элементного анализа с сорбционным концентрированием обеспечивает надежное определение металлов платиновой группы в объектах со сложным матричным составом.К настоящему времени для этих целей синтезировано большое количество сорбентов на основе различных полимеров, неорганических оксидов, углеродных и других материалов.Сорбенты должны отвечать требованиям высокой селективности, эффективности извлечения платиновых металлов и на стадии сорбции, и на стадии элюирования, устойчивости в кислых средах, а также многократности использования, предпочтительно в динамических условиях.Общепризнанно [1], что наилучшую селективность и эффективность извлечения ионов металлов из сложных по составу растворов обеспечивает так называемая технология молекулярного распознавания (ТМР), использующая сорбенты на основе кремнезема с химически привитыми органическими лигандами макроциклического и/или линейного строения [2].В настоящей работе мы описываем способ сорбционной пробоподготовки анализируемых технологических растворов, содержащих платину, палладий и родий, на основе ТМР.Разработанные нами сорбенты на основе кремнезема с химически привитыми замещенными алкиларилсульфидами [3] обеспечивают извлечение ионов палладия(II) из растворов 0.1 -4 М HCl, содержащих до 90 г/л хлорид-иона и 10 4 -10 5 -кратные избытки макрокомпонентов, и последующее количественное элюирование палладия аммиачным буферным раствором (pH 10).Сорбент на основе кремнезема с химически привитым полиэтиленимином [4] может быть использован для селективного выделения ионов платины(IV) и родия(III) из растворов 0.1 -6 М HCl и их разделения на стадии элюирования 5%-м раствором тиомочевины в 0.01 M HCl и 20%-м раствором хлорида аммония, соответственно.Разработан способ пробоподготовки сложных растворов с использованием хроматографических колонок диаметром 8 мм, наполненных синтезированными сорбентами, имеющими оптимальные фазово-структурные характеристики с точки зрения гидролитической стабильности, ненабухаемости и скорости сорбции.Высокая селективность выделения целевых компонентов подтверждена опытами на реальных растворах переработки медно-никелевых шламов.Показано, что стабильность работы предлагаемых сорбентов сохраняется в течение не менее 10 циклов сорбции-десорбции.

For the first time, widespread aqueous biphasic polymer-salt extraction system was applied for selective separation of Pd(II) and Pt(IV) from chloride technological solutions by countercurrent chromatography using a rotating coiled column (an analog of centrifugal extractor). The principle novelty of the pro-posed approach is the possibility of multistage extraction process and the needlessness to add any spe-cific reagents for targeted metal binding. The results showed that the use of poly(ethylene glycol)-150 0 (PEG-150 0) as a stationary phase allows 96-100% of both Pd(II) and Pt(IV) to be recovered from chloride solutions containing copper and nickel. To obtain individual solutions of targeted metals it is enough to change the composition of the salt-rich phase for stripping stage, in particular the salt concentration and pH value. The final purity of the targeted metal fractions obtained after their extraction from model tech-nological solutions is >= 99.9%. The components of the aqueous biphasic system are recyclable, non-toxic, available, and widespread in laboratory and technology practice. A scheme of the multistage separation of platinum metals using a rotating coiled column is proposed. (c) 2021 Elsevier B.V. All rights reserved.