Vol 78, No 5 (2023)

This review is devoted to the consideration of prospects and directions for the development of methods and approaches to the analysis of high-purity industrial gases and volatile hydrides, chlorides, fluorides, and organoelement compounds with natural and isotopically enriched compositions. The currently known capabilities for the determination of impurities in them using mass spectrometry, IR spectroscopy, gas chromatography, and chromatography–mass spectrometry are analyzed.

Rare earth elements (REEs) are currently used in fertilizers, but their behavior in the soil–plant system remains poorly studied. The assessment of the binding of REEs to various organomineral phases of soils remains an important task. Using soddy-podzolic soil and typical chernozem as examples, we performed a comparative study of the dynamic fractionation of REEs in a rotating coiled column (RCC) and a microcolumn (MC). We isolated the exchangeable fraction, specifically adsorbed fraction, and fractions bound to manganese oxides, bound to organic matter, and bound to amorphous and weakly crystallized iron and aluminum oxides using, 0.05 M Ca(NO3)2, 0.43 M CH3COOH, and a 0.1 M NH2OH·HCl solution (pH 3.6), a 0.1 M K4P2O7 solution (pH 11.0), and a 0.1 M (NH4)2C2O4 solution (pH 3.2), respectively. Concentrations of elements in the initial samples and eluate fractions were determined by atomic emission spectrometry and inductively coupled plasma mass spectrometry. The results suggest that the main extractable REE form (up to 40% of the total content) is provided by organometallic complexes extracted with a 0.1 M K4P2O7 solution. For chernozem (soils with a high content of organic matter), fractionation in the RCC and MC yielded comparable results. For soddy-podzolic soil, some differences were observed in the isolation of the first three fractions: exchangeable, specifically adsorbed, and bound to manganese oxides. Both RCC and MC can be successfully used for the dynamic fractionation of REE in soils; however, it is preferable to use an MC in analyzing many samples as a simpler and more affordable device.

We studied the conditions for the adsorption of zinc, cadmium, and mercury(II) ions on a modified adsorbent based on an ARA-8p highly basic anion exchange resin and a Rhodanine derivative, 5-(4-carboxyphenyl-azo)rhodanine (ARA-8p-p-KBAR), in a batch mode. The values of pH, phase contact time, and adsorbate concentration at which the maximum recovery of zinc, cadmium, and mercury(II) ions was achieved were determined. The adsorption capacity of the adsorbent for the adsorbed ions was determined from the obtained adsorption isotherms. The calculated value of the free energy shows that adsorption proceeds with the formation of an ionic bond. Eluents were selected to ensure the quantitative desorption of zinc, cadmium, and mercury(II) ions. The interfering effect of macrocomponents and trace elements of water was studied; zinc, cadmium, and mercury(II) ions were quantitatively adsorbed by this adsorbent from a solution of a complex composition. A procedure was developed for the adsorption–atomic-absorption determination of zinc, cadmium, and mercury(II) ions in various water samples.

New adsorbents based on silica and polystyrene–divinylbenzene (PS–DVB) for hydrophilic interaction liquid chromatography (HILIC) with eremomycin in functional layers were obtained. The chromatographic properties of the new adsorbents were assessed using the Tanaka test for hydrophilic stationary phases and by studying the retention of substances of various classes in HILIC, chiral, and reversed-phase chromatography modes. It was shown that the use of eremomycin to create functional layers leads to an increase in the hydrophilicity of the adsorbents on different types of substrates and ensures the shielding of their charge. Eleven nitrogenous bases, nucleosides with an efficiency of up to 25 000 tp/m, or seven vitamins with an efficiency of up to 40 000 tp/m can be separated on a modified sorbent based on aminopropyl silica, and three different HPLC modes can be implemented on the sorbent with eremomycin based on PS–DVB.

A procedure is developed for the high-precision determination of matrix elements of high-purity glasses of the Ga–Ge–Te–I system, containing from 5 to 15 at % Ga, from 10 to 20 at % Ge, from 69 to 75 at % Te, and from 1 to 6 at % I, using inductively coupled plasma atomic emission spectrometry. The procedure includes two stages independent of each other: determination of the ratio of the mass fractions of Ga and Te to the mass fraction of Ge (stage 1) and determination of the mass fraction of I (stage 2) in the glass sample. Based on these values, the mass and mole fractions of each matrix element of the analyzed sample were calculated. Sample preparation includes the acid dissolution (provides quantitative transfer of Ga, Ge, and Te into the solution) and alkaline opening (provides quantitative transfer of I into the solution) of samples. The accuracy of the results of analysis was confirmed by comparing the results of an analysis of model solutions and model glass samples with the calculated composition. The estimated uncertainty of the results of analysis is 0.05–0.1 at % at P = 0.95.