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Vol 79, No 10 (2024)
REVIEWS
CHROMATOGRAPHIC METHODS IN THE IDENTIFICATION AND DETERMINATION OF THE COMPONENT COMPOSITION AND QUALITY OF WINES
Abstract
A review of the literature and regulatory documents on the identification and determination oforganic compounds that form the component composition and consumer properties of wines is presented.It is noted that the capabilities, informative value and versatility of modern chromatographic methods incombination with mathematical software have significantly increased the degree of automation and reliability of obtaining data on the identification and determination of a wide range of components in wine.The conditions for determining high and low concentrations of organic compounds included in the component composition and determining the qualitative and regional characteristics of wines are discussed. Tosolve the problems of identification and determination of the components responsible for the advantagesand disadvantages of wine products, various methods of gas chromatography and mass spectrometry gaschromatography are most widely used, providing reliable determination of relatively volatile components.Non-volatile components of wines are determined by high-performance liquid chromatography with various detection methods, as well as high-performance capillary electrophoresis. The main approaches toestablishing the profile and regional affiliation of wines by component composition, combining the capabilities of modern analytical methods with statistical analysis methods, such as multiple regression analysis,general linear models, multidimensional scaling, covariance and canonical analysis, classification and machine learning methods, neural networks, are analyzed. Examples of their use in practice are demonstrated.
Zhurnal Analiticheskoi Khimii. 2024;79(10):1049-1077
1049-1077
ORIGINAL ARTICLES
EFFECTIVENESS OF SORBENTS WITH VARIOUS ALLOTROPIC FORMS OF CARBON, INCLUDING MODIFIED CARBON NANOTUBES
Abstract
The sorption of ions of toxic Be(II), Bi(III), Cd(II), Cr(III), Pb(II) and noble metals Ag(I),Au(III) and Pd(II) from aqueous media on carbon nanotubes, (CNT), a magnetic nanosorbent consistingof from CNTs and magnetic nanoparticles of magnetite, (CNT@MNP), as well as activated carbon (AC).The advantage in the capacity of sorbents with CNT compared to AC is demonstrated by about 1.5-2times.The dependence of the sorption capacity of the synthesized magnetic sorbent on the morphology of CNTsobtained on catalysts of the iron subgroup: Ni - CNT(Ni), Co. - CNT(Co) and Fe - CNT(Fe) wasfound. The advantage of CNT@MNP in comparison with other carbon sorbents in the separation of solidand liquid phases by magnetic solid-phase extraction is shown, as well as the cost-effectiveness of composite sorbents containing CNT(Co) and CNT(Fe), which, when individually used as sorbets, do not givesatisfactory results. Using the studied carbon sorbents, methods have been developed and metrologicalcharacteristics of the determination of elements in aqueous solutions by the method of arc atomic emissionanalysis are presented.
Zhurnal Analiticheskoi Khimii. 2024;79(10):1078-1088
1078-1088
MICELLAR MICROEXTRACTION WITH ALKYL POLYGLYCOSIDES FOR PRECONCENTRATION AND SPECTROPHOTOMETRIC DETERMINATION OF PHOSPHATE IONS IN AQUEOUS MEDIA
Abstract
A micellar microextraction technique has been developed for the preconcentration and spectrophotometric determination of phosphate ions in aqueous media based on the formation of a reduced formof molybdenum phosphoric heteropolyacid and its extraction from the aqueous phase into a supramolecularsolvent. In this case, in situ formation of the supramolecular solvent phase occurs when an amphiphile anda coacervation agent are introduced into the aqueous phase. The possibility of using biodegradable alkylpolyglycoside (C8-C10) as an amphiphile and carboxylic acids as coacervation agents has been studied. It isshown that in the acidic medium required for the formation of the reduced form of molybdenum phosphoric heteropolyacid, the phase of the supramolecular solvent is separated. The maximum absorbance of theextract is achieved using pivalic acid as a coacervation agent. The limit of detection (3σ) for phosphate ionsis 5 μg/L. The technique is environmentally friendly and does not require the use of expensive equipment.
Zhurnal Analiticheskoi Khimii. 2024;79(10):1089-1096
1089-1096
SOME ASPECTS OF THE DEVELOPMENT OF A TECHNIQUE FOR THE SELECTIVE DETERMINATION OF VITAMIN E ON THE SURFACE OF HUMAN SKIN WHEN APPLYING OIL PREPARATIONS
Abstract
A simple technique has been developed for the selective determination of α-tocopherol acetate(vitamin E) in an oily cosmetic product in order to study the sorption capacity of human skin and the uniformity of the distribution of the drug on its surface. The technique is designed to determine vitamin Eon the surface of human skin after applying it in the form of an oil solution. The determination is carriedout by the analyte’s own absorption, without the use of additional reagents (ascorbic acid and alkali). Thetechnique includes extraction of vitamin E with isopropanol and registration of the analytical signal by UVspectrometry. The calibration schedule is linear in the range of 0.02-0.1 mg of vitamin E/ml. Based onthe equation of the calibration graph and the tangent of its angle, the limit for determining vitamin E is calculated, equal to 0.5 micrograms/ml. It is shown that this variant of the method is reproducible, selective,express and simple.
Zhurnal Analiticheskoi Khimii. 2024;79(10):1097-1103
1097-1103
VANADIUM (V) INTERACTION WITH 4-(2′,3′,4′-HYDROXYPHENYL)-3-NITRO-5-SULFOAZOBENZENE IN THE PRESENCE OF CATIONIC SURFACTANTS
Abstract
The complexation of vanadium(V) with 4-(2′,3′,4′- trihydroxyphenyl)-3-nitro-5-sulfoazobenzene (R) in the presence of cationic surfactants (CSs) ”- cetylpyridinium chloride (CPCl),cetylpyridinium bromide (CPBr) and cetyltrimethylammonium bromide (CTMABr). Vanadium(V) c R ata ratio of components 1∶2and pH 5.0-5.5 forms a colored complex that has maximum light absorptionat 449 nm; the reagent under these conditions absorbs light at 395 nm. In the presence of KPA, mixedligand complexes are formed with a component ratio V(V) : R : KPA =1∶2∶2, while a bathochromicshift of the maximum in the absorption spectrum occurs, and the pH value of the maximum complexformation shifts to a more acidic medium compared to the homogeneous ligand complex V(V)-R. The lightabsorption of the complexes V(V) : R : CPCl, V(V) : R : CPBr and V(V) : R : CTMABr is maximum at 457,461 and 466 nm, respectively. The output of the complexes is maximum at pH 3.5-4.0 (V(V) : R : CPCland V(V) : R : CPBr) and at pH 2.5-3.0 (V(V) : R : CTMABr). The formation of homogeneous andmixed ligand vanadium(V) complexes is influenced by reaction time, temperature and concentrations ofreacting components. The values of stability constants found proved the high stability of the resultingmixed ligand complexes. The specific electrical conductivity of complexes under optimal conditions ofcomplex formation was determined by the method of conductometric titration. Calibration graphs for thedetermination of vanadium(V) in the form of homogeneous and mixed ligand complexes are linear. Thein fluence of foreign ions and masking substances on the determination of V(V) in the form of homogeneousand mixed ligand complexes was analyzed and it was shown that in the presence of CSs the selectivity of thereaction significantly increases. The analysis of water samples from Lake Khanbulana, Lankaran districtof the Republic of Azerbaijan, according to the developed methodology, showed the presence of smallamounts of vanadium(V).
Zhurnal Analiticheskoi Khimii. 2024;79(10):1104-1109
1104-1109
THERMODYNAMIC MODELING OF THE COMPOSITION OF THE MAIN BACKGROUND IONS AND DETERMINATION OF THE GAS KINETIC TEMPERATURE IN A NORMAL (HOT) INDUCTIVELY COUPLED PLASMA
Abstract
The possibility of studying the manifestation of the main background ions formed by the main elements of inductively coupled plasma (H, N, O and Ar) by the method of thermodynamic modeling underthe operating parameters of the normal (“hot”) plasma regime is considered. Such ions, which create thestrongest spectral interference in the mass spectra, are always observed when introducing aqueous (“wet”)sample solutions into inductively coupled plasma (ICP-MS) mass spectrometers. The quantitative composition of the main background ions in ICP-MS, depending on the plasma temperature, was calculated using thermodynamic modeling in the temperature range from 3000 to 8000 K. It is compared with experimentaldata from measurements of the mass spectra of the main background ions and a high degree of correlation between theoretical and experimental results is shown. The coincidence of calculations and experiments confirms the correctness of the thermodynamic model of thermochemical processes used in ICP-MS andits applicability for subsequent calculations in solving analytical problems. By comparing the theoreticaland experimental mass spectra of the main background ions of the ICP in the normal mode, the possibilityof an unambiguous assessment of the gas kinetic temperature of the plasma was confirmed. It was foundthat the calculated and experimental data on concentrations only for NO+ ions do not coincide with thepatterns noted for other background ions in the normal ICP mode.
Zhurnal Analiticheskoi Khimii. 2024;79(10):1110-1121
1110-1121
VALIDATION OF THE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR THE DETERMINATION OF PHTHALATES IN WATER AT THE TRACE LEVEL ONLINE
Abstract
A method for determining phthalates in water has been validated, including sorption of hydrophobic components of the sample on a liquid chromatograph column and separation of concentrated analytesby reverse-phase HPLC online: for quantitative determination of priority phthalates (PPs) in surface watersat the trace level; qualitative assessment of the ratio of stable carbon isotopes 13C/12C in PP composition.The absence of the contribution of PP from the laboratory background to the measurement results is shown.The limits of determination (0.15-0.22 µg/l) and the accuracy of determination (±δ =10-20%) were established when using the method of reverse-phase HPLC online and UV detection of analytes. The boundaryvalues of the 13C/12 C isotope ratio are substantiated for a qualitative assessment of the results of measuringthe value of Δ13С in the structure of di(2-ethylhexyl)phthalate and its entry into the waters of Lake Baikalfrom biogenic and abiogenic sources is detected. The method of determining PP by reverse-phase HPLCwith UV detection online in the field on a portable liquid chromatograph was tested, the concentrationranges of di-n-butyl phthalate (from 0.15 to 1.6 µg/l) and di(2-ethylhexyl)phthalate (from 0.22 to 1.6 µg/l)in the coastal zone of Lake Baikal were estimated.
Zhurnal Analiticheskoi Khimii. 2024;79(10):1122-1131
1122-1131
CHROMATO-MASS SPECTROMETRIC DETERMINATION OF HYDROXYLATED POLYAROMATIC HYDROCARBONS IN URINEBY DISPERSION LIQUID-LIQUID MICROEXTRACTION AND DERIVATIZATION IN THE INJECTOR PORT
Abstract
A simple, rapid and sensitive method has been developed for the determination of hydroxylatedpolycyclic aromatic hydrocarbons (2-hydroxynaphthalene, 2-hydroxyfluorene, 9-hydroxyphenanthrene,3-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1-hydroxypyrene, 6-hydroxychrizene) in urine by gaschromatography-mass spectrometry. Sample preparation is based on dispersion liquid-liquid microextraction with trichloromethane in an acidic medium. Derivatization is carried out in the heated port of theinjector with the reagent N,O-bistrimethylsilyltrifluoroacetamide. The type of dispersing solvent was experimentally selected, and using a three-factor experiment, the optimal ratio of the following factors wasestablished: pH values, volume of the dispersing solvent, and extraction time. For chromatography-massspectrometric analysis, a high-temperature NT-8 capillary column was used in the temperature gradient mode. The linearity range of the calibration function is 0.5-100 ng/ml. The developed method for thedetermination of hydroxylated PACs in urine has been tested on urine samples of aluminum production workers.
Zhurnal Analiticheskoi Khimii. 2024;79(10):1132-1140
1132-1140
EVENTS
Anniversary of A. G. Revenko
Zhurnal Analiticheskoi Khimii. 2024;79(10):1141-1142
1141-1142
Anniversary of V. V. Malakhov
Zhurnal Analiticheskoi Khimii. 2024;79(10):1143-1144
1143-1144