The objective of this work is to study MOFs with ligands containing thienothiophene groups as linkers and evaluate their practical application as sorbents for mercury removal from water. This evaluation will be compared with MOFs containing 2,6-naphthalenedicarboxylic acid and terephthalic acid linkers. The study of Hg2+ sorption from solutions was carried out by shaking the MOFs (10 mg) with the solution at 25 degrees C for 24 hours. Determination of chemical elements in solutions was performed using an Agilent 8800 triple quadrupole ICP-MS spectrometer (ICP-QQQ) equipped with an octopole reaction-collision cell in a standard configuration. Within 24 hours, 97.8% of Hg2+ ions were removed from the solution, even at an initial Hg2+ concentration as low as 1 mg center dot L-1. An important part of the work was studying the possibility Zr-ttdc regeneration for repeated use. Using iodide solution as a desorbing agent proved more productive, ensuring the desorption of Hg2+ through competitive complex formation due to the high stability constants of the corresponding mercury complexes. With a 0.1 M potassium iodide solution at pH 6.5, 99% of the sorbed mercury was desorbed in one desorption cycle. The efficiency of [Zr6O(4)(OH)(4)([3.2-b]ttdc)6] in adsorbing mercury from aqueous solutions was thoroughly evaluated and compared to [Zr6O(4)(OH)(4)(bdc)6] and [Zr6O(4)(OH)(4)(2.6-ndc)6], which lack sulfur-containing linkers. The findings highlight the potential of functionalized MOFs for water purification as well as application in analytical chemistry for the concentration of mercury. Notably, [Zr6O(4)(OH)(4)([3.2-b]ttdc)6] demonstrated stability in water in a wide pH range, underscoring its promise for diverse environmental chemistry applications.

Metal-organic frameworks (MOFs) have gained growing attention in analytical chemistry particularly for the pre-concentration of trace elements prior to their analysis using advanced instrumental techniques. Despite their promising structural and functional properties for selective extraction and enrichment of elemental species, their application in speciation remains relatively underexplored. Mercury, one of the most hazardous pollutants, exists in environments in various chemical species that differ significantly in toxicity, mobility, and bioavailability. Therefore, developing new methods for mercury speciation in environmental samples continues to be a pressing goal in analytical chemistry. This study presents a novel approach for the speciation of inorganic and organic mercury in water. This approach is based on pre-concentration using dynamic solid phase extraction (SPE) followed by their determination using cold vapor inductively coupled plasma atomic emission spectrometry (CV-ICP-AES). An original dynamic SPE-procedure based on the use of [Zr6O4(OH)4([3.2-b]ttdc)6], MOF that incorporates a Zr(IV) fragment and thienthiophene-dicarboxylic acid as a linker, was designed. The developed method allows determination of the species most often found in natural and contaminated environments, mercury(II) and methylmercury, at levels between 0.008 and 0.01 mu g L-1. The developed assay demonstrates a high efficiency, low detection limits, and admissible analysis duration. The reliability of the data was confirmed by the spiking method.

A large number of publications have been devoted to the study of aerosol atmospheric transport, but the low-temperature transfer of metals and metalloids as a part of gas flow remains poorly understood. The present work is devoted to the study of gas stream composition using an approach based on the collection of nascent condensate upon cooling of the air flow formed over the surface of contaminated sites. A special laboratory unit was designed to collect the condensate followed by the study of its composition using atomic emission and mass spectrometry. The main novelty of this work consists of the application of the single-particle ICP-MS technique to obtain qualitative information concerning the state of the elements in the condensates. Gold and silver are most likely present in the samples as nanoparticles; arsenic, selenium, tin and lead are present both as nanoparticles and as soluble forms; and barium and mercury are present only in soluble forms. The condensed phase contains As, Hg, Au, Ag, Pb and Sn at the ppb level, while the main elements of the tailings material (Fe, Ba, Cu, Zn and others) are present at the ppm level, which exceeds the background concentration.

Mercury is the most dangerous pollutant prone to the formation of the toxic forms. Therefore, the problem of cleaning mercury contaminated areas seems to be very relevant. Numerous works have been published on the study of mercury uptake depending on the type of plants and natural conditions, but less attention was paid to studying the influence of element’s speciation on their accumulation ability. In the present work, the results of laboratory experiments on the assessment of accumulation efficiency of white mustard growing in medium with artificially introduced mercury species such as HgCl2, CH3Hg Cl and HgS are discussed and bioconcentration factors were evaluated while maintaining plant viability. It was shown that methylmercury is the most intensively accumulated specie while mercury sulphide is more imbibed than HgCl2 during 3 months experiment in spite of its negligible solubility in water. Based on the assumption that the cause of such a phenomenon is associated with the transformation of mercury species in the process of the plants growth, mercury speciation in the growing environment has been studied in dynamics and the results obtained confirmed this suppose. It appeared that HgCl2 and HgS are transformed into other chemical forms.

A detailed study of the Re-S-Br system in the temperature range (650 - 1150 degrees C) of the formation of hexarhenium thiobromides with the general formula Re6S4+nBr10-2n, has revealed the features of phase formation and the factors influencing the production of pure phases. It was found that in reactions with a given stoichiometry 6Re + nS, a mixture of products is usually formed, namely a compound based on a cluster core with the targeted Re/S stoichiometry Re6Sn, an admixture compound with Re6Sn+1 core, and a soluble by-product (3-5% of the total mass), consisting of rhenium bromides and thiobromides. It was found that the composition of the byproduct (Re/S ratio) has a significant effect on the fraction of the admixture compound with higher sulfur content. The slow cooling rate of the reaction mixture, leads to the obtaining of a pure target compound with the {Re6SnBr8-n} cluster core. In the course of the study of the Re-S-Br system, the crystal structure of Re6S7Br4 was solved (space group R-3c, a = 9.5804(2) ?, c = 31.0676(10) ?, V = 2469.48(13) ?3, Z = 6). The study of the thermal behavior showed that the stability of Re6S4+nBr10-2n increases with increasing sulfur content in the cluster core. XPRD data showed that the decomposition of octahedral cluster thiobromides leads to the formation of sulfur-rich phases. This process is accompanied by the release of elemental bromine, metallic rhenium and the formation of soluble by-products with the overall composition "Re2SBrx".

Seafood consumption may induce health risks due to its contamination by pollutants. In this study, the two-stage probe atomization technique (TPA) was combined with graphite furnace atomic absorption spectrometry (GFAAS) to develop a novel procedure for determining Cd, Pb and Zn in mussels collected in the Sea of Japan (Russia). The application of TPA eliminated organic matrix interferences during GFAAS determination of heavy metals and allowed significant reduction of the sample pretreatment processes. The procedure involved the formation of a suspension of treated lyophilized mussels that were inserted into graphite furnace. The limits of detection using the optimized conditions were 0.8, 10, and 0.4 ng/g for Cd, Pb, and Zn, respectively. Inductively coupled plasma - optical emission spectrometry (ICP-OES) was employed to characterize the accuracy of the developed technique. The concentrations of heavy metals in Crenomytilus Grayanus mussel tissues from Peter the Great bay did not exceed 8.2, 31 and 475 mu g/g for Cd, Pb, and Zn and are considered to have no negative effects upon human health.

Несмотря на широкое применение гибридных методов в анализе, их использование для изучения состава сложных смесей в растворе, как правило, ориентировано на модельные системы.Последнее обусловлено тем, что для идентификации компонентов смеси необходимы индивидуальные соединения, доступность которых весьма ограничена.Поэтому разработка новых подходов для идентификации веществ неизвестного состава в отсутствии или при ограниченных возможностях использования индивидуальных соединений представляется актуальной проблемой, как неорганической синтетической химии, так и экологической химии.В работе представлен подход, в основе которого лежит сочетание различных методов разделения с элемент-и масс-селективными детекторами (ВЭЖХ-ИСП-АЭС, ВЭЖХ-ИСП-МС, ВЖХ-ЭСИ-МС и КЭ-ИСП-МС).Для решения подобных задач предложены различные методологические приемы, в числе которых: оценка стехиометрических соотношений элементов, в регистрируемых аналитических сигналах (ВЭЖХ или КЭ) в координатах «время удерживания (или электрофоретической миграции) -интенсивность линии в ИСП-АС (ИСП-МС)»; детектирование масс ионов с учетом возможного формирования ассоциатов, образующихся в процессе электро-спрей ионизации, в том числе при взаимодействия с компонентами подвижной фазы в ВЭЖХ-ЭСИ-МС, а также использование закономерностей электрофоретической миграции исследуемых компонентов с учетом их УФ-Видспектральных характеристик.Разработанная методология с успехом применена для исследования состава смесей неорганических соединений: комплексных полиоксометаллатов различного состава, полиядерных оксогидроксокомплексов родия.Следует отметить, что промежуточная информация о составе компонентов смеси, полученной в процессе неорганического синтеза, позволяет, с одной стороны, судить о механизме его протекания, а с другой -выбрать верное направление на пути к целевому продукту путем варьирования условий синтеза.Кроме того, использование данного подхода применительно к природным объектам позволило идентифицировать формы

Oxalate ligands in Nb V oxalate complexes are labile, making the latter convenient niobium source for preparation of new mixed W/Nb polyoxometalates under mild conditions. Reactions of [NbO(C 2 O 4 ) 2 (H 2 O) 2 ] – with [α‐B‐XW 9 O 33 ] 9– (X = As, Sb) result in formation of sandwich‐type anions. For X = As, [(α‐B‐AsW 9 O 33 ) 2 (NbO) 3 (H 2 O)] 9– and [(α‐B‐AsW 9 O 33 ) 2 (NbO) 2 (H 2 O)] 12– were the products. In the case of antimony, [(α‐B‐SbW 9 O 33 ) 2 {Nb(C 2 O 4 )} 2 ] 12– anion with two trapped {Nb(C 2 O 4 )} 3+ fragments was isolated and structurally characterized. Solution behavior of the new heteropolyniobotungstates was studied by combined HPLC‐ICP‐AES technique.

Reactions of [Ru(NO)Cl5]2- with pseudotrivacant B-α-[XW9O33]9- (X = AsIII, SbIII) at 160 °C result in the rearrangement of polyoxometalate backbones into {XM18} structures. In the case of arsenic, oxidation of AsIII to AsV takes place with the formation of a mixture of plenary and monosubstituted Dawson [As2W18O62]6- and [As2W17Ru(NO)O61]7- anions, of which the latter was isolated as Me2NH2+ (DMA-1a and DMA-1b) and Bu4N+ (Bu4N-1) salts and fully characterized. Both α1 and α2 isomers of [As2W17Ru(NO)O61]7- were present in the reaction mixture; pure [α2-As2W17Ru(NO)O61]7- was isolated as the Bu4N+ salt. In the case of antimony, [SbW9O33]9- is converted into a mixture of [SbW18O60]9- and [SbW17{Ru(NO)}O59]10-. The formation of trisubstituted [SbW15{Ru(NO)}3O57]12- as a minor byproduct was detected by HPLC-ICP-AES. The monosubstituted [SbW17{Ru(NO)}O59]10- anion was isolated as DMAH+ (DMA-2) and mixed inorganic cation (CsKNa-2) salts and characterized by XRD, HPLC-ICP-AES, EA and TGA techniques. X-ray analysis shows the presence of the {Ru(NO)}-group in the 6-membered ("equatorial") belt of the Sb-free hemisphere. The experimental findings were confirmed and interpreted by means of quantum chemical calculations.

An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Reactions of K7H[Nb6O19], K6[(OH)TeNb5O18] or Na8[Ta6O19] with Mn(OAc)2 in the presence of H2O2 lead to the formation of brown solutions. In the case of the hexaniobate crystallization gives orange crystals of K9Na2[HMn(Nb6O19)2]·18·5H2O (1), characterized by XRD, XRPD and EPR. Magnetic properties and stability of 1 in aqueous solution have been studied. The rate of formation of the telluropentaniobate analogue, [Mn(TeNb5O19)2]10−, is much more slow. It is relatively stable in solution, though less so than the hexaniobate complex, and could not be isolated. In the case of hexatantalate the reaction solution is unstable and transforms into an intractable brownish amorphous precipitate. EPR studies of the solids isolated from the reactions with [(OH)TeNb5O18]6− and [Ta6O19]8− suggest oligomeric or polymeric nature of the solids, with the formation of {MnIVxOy} aggregates.

In this research combined HPLC-ICP-AES technique was used to study formation of mixed [XW11O40]n− (X = P, Ge, B) complexes.

This paper summarizes the application of the coupled HPLC-ICP-AES technique to study the substitution of niobium by tungsten in [Nb6O19]8− or [(OH)TeNb5O18]6− Lindqvist anions and the screening of mixed [PMo12−xNbxO40]n− Keggin anion formation.

During the last few decades, phytoremediation process has attracted much attention because of the growing concerns about the deteriorating quality of soil caused by anthropogenic activities. Here, a tandem phytoremediation/biorefinery process was proposed as a way to turn phytoremediation into a viable commercial method by producing valuable chemicals in addition to cleaned soil. Two agricultural plants (Sinapis alba and Helianthus annuus) were grown in moderately contaminated soil with ca. 100 ppm of Ni and further degraded by a fungal lignin degraderPhanerochaete chrysosporium. Several parameters have been studied, including the viability of plants, biomass yield, and their accumulating and remediating potentials. Further, downstream processing showed that up to 80% of Ni can be easily extracted from contaminated biomass by aqueous extraction at mild conditions. Finally, it was demonstrated that the growth of plants on the contaminated soil could be degraded by P. chrysosporium, and the effect of nickel and biomass pretreatment on the solid-state fermentation was studied. The proposed and studied methodology in this work could pave the way for successful commercialization of the phytoremediation process in the near future.

Unambiguous identification of polyoxometalate (POM) species generated in self-assembly reactions in solution is rather problematic due to close similarity of their properties such as solubility and spectral characteristics. The situation is made more complex by protonation equilibria (which can change their analytical signals) and the lack of individual compounds to serve as standards for individual members of these mixtures. In the present work a new approach to the study of such POMs has been suggested, taking molybdovanadates [PMo12-xVxO40]-3-x as a model. The key feature of this approach consists of generation of so-called "conditional model systems" that include most of the expected components of a mixture formed by self-assembly, tracked down by reliable detection techniques, e.g., 51V NMR-spectroscopy in this particular case. Then the proposed composition of the mixture is verified and corrected by means of high-performance liquid chromatography coupled with inductively coupled plasma atomic emission spectrometry (HPLC-ICP-AES).

Photooxidation of As(III) in ternary As(III) - Fe(III) - Fulvic acid system at pH 4 was investigated by optical spectroscopy, steady-state photolysis (365 nm) and atomic-emission spectrometry with inductively coupled plasma techniques. It was found that at all values of [FA]/[Fe] ratio the main photoactive species is (OH)-O-center dot radical formed by photolysis of Fe(III) hydroxocomplexes. Addition of fulvic acid leads to mainly negative effect on As(III) photooxidation due to the following reasons: (i) slow dark reduction of photoactive Fe(III) species with formation of scattering particles and photoinert Fe(II) species; (ii) formation of photoreductive Fe(III)-FA complexes incapable to oxidize As(III), (iii) competition of both FA and Fe(III)-FA complexes for UVA quanta with FeOH2+ complex and for (OH)-O-center dot radicals with As(III). Aging of ternary system is also very important parameter leading to one order decrease of quantum yields of both Fe(II) formation and As(III) photooxidation. (C) 2017 Elsevier Ltd. All rights reserved.

The quantum yield of As-III oxidation caused by the UV photolysis (282 nm) of fulvic acid H108498 in aqueous solution was measured and a qualitative model explaining its dependence upon pH and As-III concentration was suggested.

The ability of water hyacinth (WH) and pondweed (PW) to accumulate mercury from water in gold mine tailing area was studied. Experiments were carried out in the field conditions without using a model system. An approach for mercury fractionation according to its association with various types of biomolecules (water soluble compounds, oxygen-containing ligands such as polycarboxylic acids and cell wall components) was suggested. It is based on sequential extraction of mercury to recover different compounds according to the binding strength. In all cases for WH and PW, the most portion of mercury is bound to the cell wall (63–67 and 54–64 %, for WH and PW, respectively) that works as a physiological barriers and protects the plants from negative impact of mercury ions. An approach based on the ability of plants to extract elements from tailings drainage waters that are characterized by milder conditions in comparison with strongly acidic waste material was suggested. The highest BCF values (66,500 and 32,700 for WH and PW, respectively) were obtained for plants grown in natural stream. At low levels of mercury in water (C Hgwater = 0.01–0.05 ppb) typical for tailing solutions, translocation of the element from roots to shoots decreases as concentration of mercury in WH increases. PW is preferable to use in practice for tailings remediation from mercury contamination since it does not require cultivation in a greenhouse and shows BCF values comparable with WH.

The ability of water hyacinth (Eichhornia crassipes) to uptake Ag, Ba, Cd, Mo, and Pb from waters in gold mine tailing area was studied. All experiments were carried out in the field conditions without using of model system. Bioconcentration (BCF) and translocation factors (TF) as well as elements accumulation by plant in different points of tailings-impacted area were evaluated. It has been shown that water hyacinth demonstrates high ability to accumulate Mo, Pb, and Ba with BCF values 24,360 ± 3600, 18,800 ± 2800 and 10,040 ± 1400, respectively and is efficient in translocation of Mo and Cd. The general trend of the plant accumulation ability in relation to the studied elements corresponds to their concentration in the medium. As the distance from tailings increases, concentration of Ag, Ba and Pb in plant decreases more clearly than that of Cd, while the amount of Mo accumulated by plant doesn't drop significantly in accordance with its concentration in water. Under the conditions of the confluence of river Ur and drainage stream Ba and Ag can be considered as potential candidates for phytomining.