French-Ukrainian Journal of Chemistry
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Comparative experimental and theoretical study on the molecular structure and spectroscopic properties of sideroxol isolated from Sideritis stricta and its electronic properties
Get PDFSideroxol, a kaurene diterpene, was obtained from the acetone extract of Sideritis stricta plant. The ground-state molecular geometry, vibrational frequencies, and NMR chemical shifts were also investigated by using various density functional theories and Pople basis sets. The computed geometries are in good conformity with the experimental data. The comparison between theory and experiments indicates that B3LYP and M06 methods with the 6-31G(d) basis set are able to provide satisfactory results for predicting vibrational and NMR properties. There seems to be no significant effect of addition of diffuse and polarization functions in the basis set used herein
The Complex Method for Measurement Polycyclic Aromatic Hydrocarbons in Soil, Water, Plant Products
Get PDFThe measurement of xenobiotics (polycyclic aromatic hydrocarbons (PAHs) group) in agricultural objects: soil, water, plant products was developed and tested by the high performance liquid chromatography method in this work. Our investigation was carried out by using laboratory samples taken from the research farm "Snitynka". Optimal modes of high-performance liquid chromatography method with a fluorescent detector (HPLC/FLD) were established for xenobiotics measurement: benzo(a)anthracene, benzo(a)pyrene, benzo(e)pyrene, benzo(b)fluorine, chrysene and their mixtures. Metrological characteristics of PAHs measuring were established: the limit of quantitative analysis (LOQ = 1.0 μg/kg), the limit of detection (LOD = 0.25 μg/kg), measuring range 1.0 - 10.0 μg/kg, the total measurement error (%) for each xenobiotics content average did not exceed 20%. The approbation of the methodology was performed in series of 50 model samples in the concentration range of each xenobiotics from 1.0±0.1 μg/kg to 10.0±0.1 μg/kg and in series of 50 natural samples. It is established that the developed method allows to unify laboratory control of PAHs and improves the process of monitoring analysis of xenobiotics
Difference spectrophotometric method for the determination of Fluphenazine hydrochloride in tablets using peroxomonosulfate
Get PDFThe oxidative derivatization method using potassium hydrogenperoxomonosulfate for the indirect spectrophotometric determination of Fluphenazine hydrochloride is presented. Potassium hydrogenperoxomonosulfate is introduced as a derivatizing agent for Fluphenazine hydrochloride, yielding the sulfoxide. This reaction product was successfully used for the spectrophotometric determination of the Fluphenazine hydrochloride. The UV spectroscopic detection of the sulfoxide proved to be a more robust and sensitive method. The elaborated method allowed the determination of Fluphenazine hydrochloride in the concentration range of 0.2-30 µg mL-1. The molar absorptivity at 349 nm is 5.6×103 (dm3cm-1mol-1). The limit of quantification, LOQ (10S) is 0.24 µg/mL. A new spectrophotometric technique was developed and the possibility of quantitative determination of Fluphenazine hydrochloride in tablets 5.0 mg was demonstrated. The present method is precise, accurate and excipients did not interfere. RSD for Fluphenazine Hydrochloride 5.0 mg tablets was 1.37 %
Chemistry and technology of roasting and extracting different types of coffees with preservation of taste and aromas
Get PDFThe article considers the chemistry and technology of the methods of roasting and extracting different types of coffees, Arabica and Robusta. Parameters and equipment to improve roasting in microwave ovens and distillation of coffee with water-alcohol vapors demonstrate that the weight loss of green coffee beans has decreased from 18-20% to 12-15%. Mass spectroscopic analysis of extracts of coffee substances with water vapor and alcohol identified 36 substances, 14 of them being the main substances that create a unique bouquet - the taste and aroma of coffee. We have experimentally demonstrated that aqueous distillates of coffee extracts accelerate 1.5-2.5 times the metabolism of ethyl alcohol in the human body to the acceptable concentrations of 0.2 ‰ per ppm
Levels and health risk assessment of organochlorine pesticide residues in vegetables from Yamaltu area in Gombe, Nigeria
Get PDFThe study determined the levels of organochlorine pesticides (OCPs) residues and assesses health risks linked with the consumption of vegetables cultivated in the Yamaltu area in Gombe, Nigeria. OCPs residues were solvent extracted and analyzed with a high performance liquid chromatography equipped with UV/VIS Detector. The mean concentrations of ten detected OCPs residues were almost all above the set limit of EU/WHOMRL. The estimated daily intake of OCPs from samples was below the acceptable daily intake, hazard index estimated were <1, indicated no probable non-carcinogenic health effect, while the carcinogenic health effect showed that children were more vulnerable for the consumption of the contaminated vegetables
Recyclization reactions of 8,10-dibromocamphor with Grignard and organolithium compounds
Get PDFGrignard reagents and organolithium compounds react with 8,10-dibromocamphor to afford substituted 1-methyl-2-methylenebicyclo[3.2.0]heptanes. Recyclization proceeds via intramolecular enolate alkylation and Grob fragmentation of the reaction intermediates. All compounds have been characterized by 1H, 13C and 19F NMR spectroscopy and their chemical composition proved by HRMS analyses. The relative spatial arrangement of substituents in the molecule of (1-methyl-2-methylenebicyclo[3.2.0]heptan-6-yl)diphenylmethanol was studied by NOESY experiments.
Effect of strontium atoms substitution on the features of two-slab structure of Sr1-xCaxLa2Sc2O7 scandates
Get PDFEffects of substitution of the Strontium atoms with smaller Calcium atoms on the structural features of the Ruddlesden-Popper SrLa2Sc2O7 two-slab compound is established. The crystal structure of orthorhombic Sr0.85Ca0.15La2Sc2O7 phase with maximum degree of substitution was determined by the Rietveld method (Fmmm space group, a = 0.5766(2) nm, b = 0.5743(2) nm, c = 2.0522(7) nm). Comparison of the structural features of SrLa2Sc2O7 and Sr0.85Ca0.15La2Sc2O7 shows that such type of substitution leads to a decrease in the (La,Sr)2 - О2 interblock bond length (from 0.222 (2) nm at x = 0 to 0.215 (1) nm at x = 0.15). The decrease in interblock bond length brings the constitution of the two-dimensional structure Sr1-хCaxLa2Sc2O7 closer to the structure of the three-dimensional perovskite, leads to its instability at х > 0.15 and gives a reason to conclude that this factor causes a limitation of region of the Sr1-хCaxLa2Sc2O7 solid solutions with a slab perovskite-like structure. Presence of such structure changes is the precondition for regulation of structural-dependent features of the materials on the base of scandates alkaline-earth and rare earth metals
The effect of ultrasound on the treatment of domestic wastewater from organic and biological contamination
Get PDFThe effectiveness of the uses of ultrasonic cavitation for wastewater treatment has been investigated. The influence of the gases of different nature (nitrogen, oxygen, air, mixture of nitrogen and oxygen gases in the ratio of 1:1) on the destruction of organic and biological contaminants has been carried out. It is confirmed that ultrasound cavitation increases the purification effect of gases. It is established that the deepest purification from organic contaminants was achieved by the common action of air with ultrasound, the degree of water purification from organic compounds being 80% and from biological contaminants – by the common action of nitrogen with ultrasound – the degree of water purification from biological compounds being 99,5%. The effective rate constant was calculated
Occurrence of priority trace metals in tomatoes (Solanum lycopersicum L.) from some areas of Uasin Gishu County, Kenya
Get PDFThis study determined the concentration of zinc, lead and cadmium in tomatoes consumed in some areas of Uasin Gishu, Kenya. Samples were taken in quintuplicate from Huruma and Bahati estates (Eldoret) and Chebaiywo (Kesses) and their metalliferous content were determined by atomic absorption spectroscopy. All samples had detectable levels of trace metals, with lead recording the highest concentration of 43.20 ± 0.31 mg/kg. Zinc concentrations were below WHO guidelines. Daily intakes ranged from 8.25 × to 2.59 × mg/kg/day. Though there are no probable cancer risks, hazard quotients indicated that deleterious health effects could arise from daily consumption of tomatoes
Riskometric assessment of factors affecting population health in situational analysis features of cytochemical indicators of activity circulating and tissue leukocytes and oxidative stress as a factor of chronic inflammation
Get PDFThe study of the mechanism of oxidative stress and regulation of oxygen-dependent processes is important, as the establishment of a complex interaction between oxidative stress, oxidative protein damage and the body's antioxidant system makes it possible to clarify metabolic pathways of disease pathogenesis. In our study, we concluded that in patients with chronic non-specificinflammatory diseases of the genitals of men and women, the phagocytic activity of polymorphonuclear leukocytes is reduced mainly by the oxygen-dependent mechanism, and tissue - by the oxygen-independent. As an exception in patients with chlamydial infection, the phagocytic activity of tissue polymorphonuclear leukocytes was also reduced by an oxygen-dependent mechanism