Vol 74, No 1 (2019)

The review covers the research of the Laboratory of Chromatography of the Division of Analytical Chemistry of the Department of Chemistry of Moscow State University in the development of new stationary phases for hydrophilic interaction liquid chromatography and ion chromatography performed in 2007–2017. The principles that guided the team in selecting matrices for each type of adsorbents, approaches to the modification of surface, and the methods of forming functional layers are discussed. The revealed regularities of changes in the chromatographic properties of materials on varying the structural fragments of the functional layers are described in detail, which enabled the authors to develop approaches to obtaining stationary phases that are not inferior to commercial analogs in efficiency and selectivity.

The results of a systematic study of sorption systems for the reversible group extraction of Ru, Rh, Pd, Ir, and Pt and their subsequent determination by inductively coupled plasma mass spectrometry are presented. The sorption system includes an sorbent, a reagent, and a desorbing solution. Purolite MN-200, НP, and Styrosorb hypercrosslinked polystyrene sorbents and Strata sorbents with immobilized nitrogen atoms were studied. Various aliphatic and aromatic amines were used as ion-pair amine reagents for the sorption extraction of PGMs. A possibility of the desorption of Ru, Rh, Pd, Ir, and Pt complexes with reagents of different nature was studied. Sorption systems were selected for the preconcentration of PGMs from solutions obtained after the decomposition of rocks. A flow-injection method for introducing high-salt and organic solutions into a mass spectrometer was proposed. Possible spectral and nonspectral effects were investigated, and the conditions for quantifying Ru, Rh, Pd, Ir, and Pt in the obtained preconcentrates were selected.

An overview of methods for the target determination of physiologically active components of various plants: rosavin, rosarin, and salidroside from Rhodiola rosea; ginsenosides Rb1, Rg1, Rf, and Re from the Asian ginseng Panax ginseng, pseudoginsenosides F11 and RT5 from American ginseng Panax quinquefolius; schizandrols A and B from Schisandra chinensis seeds; baiсalin, baicalein, wogonin, and scutellarin from the root of the Baical skullcap Scutellariae baicalensis; and glycyrrhizin from the licorice Glycyrrhiza glabra root is presented. Methods for the individual and group identification of a wide range of saponins contained in plants of the genus Panax, leaves of the prayer leaf Abrus precatorius L., and licorice Glycyrrhiza glabra are also considered. Methods for estimating the amount of protodioscin, dioscin, and diosgenin in the aerial parts of Tribulus terrestris and a wide range of ginsenosides in various ginseng based products using the approaches to the quantitative analysis of a multicomponent system are reviewed. The developed methods are simple and reliable; they are original and can be used to control the quality of a wide range of plant products.

An extraction-spectrophotometric method has been developed for the determination of trace molybdenum(VI) using a newly synthesized benzopyran derivative, 3-hydroxy-2-[3-(4-methoxyphenyl)-1-phenyl-4-pyrazolyl]-4-oxo-4H-1-benzopyran (HMPPB). The method involves formation of a 1 : 2 (M : L) yellow complex between Mo(VI) and HMPPB from 0.02–0.06 M H₂SO₄ medium. The Mo(VI)–HMPPB complex is easily extractable into carbon tetrachloride with 100% extraction and exhibits maximum absorbance in the wavelength region 417–423 nm. The method is made sensitive and selective to produce best extraction results by studying and optimizing parameters of acidity, reagent concentration, equilibration time and effect of diverse ions. The optimized method shows a good range of linearity (0–1.4 µg/mL), sensitivity (0.0018 µg/cm²), limit of detection (0.1 µg/mL), correlation coefficient (0.9974), accuracy, and reproducibility (±0.002 absorbance units). The proposed method is satisfactorily applied to the extraction and determination of molybdenum(VI) from different synthetic and technical samples including steel, flue dust and water samples.