Odesa National University Herald. Chemistry最新文献

{"title":"HIRSHFELD SURFACE ANALYSIS OF CRYSTALS OF COMPLEXES - PRODUCTS OF REACTION IN SYSTEMS МХ2 – 1,10-PHENANTHROLINE – GeO2 – CITRIC ACID (М = Ni, Co; X = Cl, CH3COO)","authors":"O. Buchko","doi":"10.18524/2304-0947.2021.2(78).235506","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.2(78).235506","url":null,"abstract":"Intermolecular interactions in the coordination compounds of cation-anionic type [Ni(phen)3][Ge(HCit)2]·2H2O (I), [Co(phen)3][Ge(HCit)2]⋅2H2O (II), [Co(H2O)2(phen)2]2[Ge(Cit)2]·4H2O (III) were characterized using Hirshfeld surface analysis. It was established that the biggest contribution in the Hirshfeld surface of anions have been made by the bonds H … В / О …Н (57,8 % (I), 59,6 % (II), 63,9 % (III)), H … H (28,2 % (I), 24,9 % (II), 31,4 % (III)). At the same time interactions C … H / Н … С are less significant (9,6 %, 11,2 % and 3,2 % for I, II, III, respectively). The calculated percentage contribution of different intermolecular interactions of cations in the crystals showed, that, unlike the anions, contacts H … Н (37,9 % (IА), 38,6 % (IB), 36,2 % (IIА и IIB), 38,8 % (III)) play dominating role, while contribution of H … В / О … Н is less (26,5 % (IA and IB), 28,3 % (IIA), 24,5 % (IIB), 26 2 % (III)). Furthermore, interactions C … H / Н … С are more significant than in anions (24,8 % (IА), 27,2 % (IB), 25,6 % (IIА), 26,2 % (IIB), 21,3 % (III). It is typical for cations to have С …С bonds (5,5 % in average) that give contribution less then 1 %. It was determined that voids volume in the crystals of compounds I–III is 751,74 (I), 778,21 (II) and 423,23 (III) Å3 and surface area is 1772,28 (I), 1821,36 (II) and 628,38 (III) Å2. The total volume of the voids (15 % in I, 15,7 %, in II, 22,4 % in III) testifies the lack of big cavities in the frames of the studied compounds. Thereby analysis of intermolecular interactions with the help of Hirshfeld surface analysis showed the dominating role of hydrogen bonds H … O / O …H and contacts H … H, and minor contribution of C … H / H … C and С … С bonds for all studied compounds. The absence of p-p stacking interactions between aromatic rings of 1,10-phenanthroline in the cations of complexes I–III was also pointed out.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82886705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"6,7- AND 7,8-DIHYDROXYBENZOPYRYLIUM DERIVATIVES: SYNTHESIS, PROPERTIES AND ANALYTICAL APPLICATION (REVIEW)","authors":"A. Chebotarev, S. Toporov, D. Snigur, D. Barbalat","doi":"10.18524/2304-0947.2021.2(78).233829","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.2(78).233829","url":null,"abstract":"The present review is devoted to a class of organic analytical reagents 6,7- and 7,8-dihydroxybenzopyrylium derivatives: their synthetic pathways, physicochemical properties, state in solutions, and analytical applications are described. Anion nature influence on spectral characteristics and some physico-chemical properties of 6,7-dihydroxybenzopyrylium derivatives was noted. Pathways of acid-base transformations in aqueous solutions of 6,7-dihydroxybenzopyrylium derivatives were described. It has been shown that derivatives of 6,7- and 7,8-dihydroxybenzopyrylium are capable for complexation with a number of p-, d-, and f-elements (Cu (II), Ga (III), In (III), Tl (III), Ge (IV), La (III), titanium subgroup, Bi (III), Mo (VI), W(VI) and others). Information on their composition, structure and analytical characteristics is summarized. It is noted that with the 6,7-dihydroxybenzopyrylium derivatives the simple and highly sensitive methods for the direct spectrophotometric and extraction-photometric determination of Ga(III), In(III), Tl(III), Ti(IV), Zr(IV), Hf(IV), Mo(VI), Ge(IV), Bi(III), Cu(II) have been developed. It is noted that 6,7-dihydroxybenzopyrilium derivatives complexes with Mo(VI) and Cu(II) are effectively extracted by Triton X‑100 micellar phase, which forms the basis for highly sensitive combined spectrophotometric and atomic absorption methods for their determination. The simplicity of targeted synthesis of 7,8- and 6,7-dihydroxybenzopyrylium derivatives opens the way to their use in the development of combined cloud point extraction and liquid-liquid microextraction with spectrophotometric or atomic absorption detection methods for the determination of a number of p- and d-elements.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91072397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EQUILIBRIA PROCESSES IN AQUEOUS SOLUTIONS OF K2CrO4 – HNO3 – KNO3 – H2O AND K2Cr2O7 – NaOH – KNO3 – H2O SYSTEMS","authors":"Y. Oleksii, O. Mariichak, G. M. Rozantsev, S. A. Shyshkanov, S. V. Radio","doi":"10.18524/2304-0947.2021.2(78).233833","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.2(78).233833","url":null,"abstract":"The equilibria processes in aqueous solutions of CrO42– – H+ – H2O and Cr2O72– – OH– – H2O systems were studied by pH‑potentiometric titration, mathematical modeling and UV–Vis. spectroscopy. It was established that in the CrO42– – H+ – H2O systems with acidity ZН = ν(H+)/ν(Cr(VI)) = 0–2.5 the processes of dichromate and hydrochromate anion formation and hydrolytic conversion of dichromate to hydrochromate take place, for which the logarithms of the equilibrium concentration constants were calculated by the quasi-Newton method (CLINP 2.1 software; 95 % confidence probability). The calculated values of the logarithms of the concentration equilibrium constants lgKC reliably agree with the literature data. The calculated lgKC were used to build of chromium(VI) anions distribution diagrams depending on ZH, and ZOH in solutions. For the first time, by the Pitzer method the thermodynamic equilibria constants of hydrochromate HCrO4– (lgK10 = 6,94), the dichromate anion Cr2O72– (lgK20 = 15,49) formation processes from the CrO4 2– and H+ ions, and the logarithm of equilibrium constant of the interconversion of the dichromate anion to the hydrochromate anion (lgK30 = –1,61) were calculated. Mathematical modeling and UV–Vis. spectroscopy show that the composition of anions in Cr2O72– – OH– – H2O solutions with alkality ZOH = ν(OH–)/ν(Cr(VI)) = 0–2.5 is identical to CrO42– – H+ – H2O systems. It is established that the experimental dependencies pH = f(Z) for the Cr2O72– – OH– – H2O system can be reliably reproduced by hydrolysis reactions of dichromate anion to hydrochromate anion and by subsequent neutralization to chromate anion with equilibrium constants calculated for processes in CrO42– – H+ – H2O solutions with same ionic strengths. The quantitative composition of chromium(VI) solutions was confirmed qualitatively by UV–Vis. spectroscopy.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84361691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"STUDY OF THE SOLUBILIZING CAPACITY OF POLYMER-COLLOID COMPLEXES FORMED WITH SODIUM ALGINATE AND CHLORIDE HEXADECYLPYRIDINIUM","authors":"A. Tymchuk, A. O. Grossu, A. Babenko","doi":"10.18524/2304-0947.2021.2(78).233827","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.2(78).233827","url":null,"abstract":"It was examined the behavior of systems which contain surfactants and biopolymers is considered by the example of cationic surfactants and sodium alginate. The rheological and surface-active properties of the systems have been experimentally investigated. It was found that the presence of oppositely charged surfactants in the solution significantly affects the properties of sodium alginate, due to the fact that associates or polymer-colloidal complexes are formed in the solution. Their formation significantly affects the solubilizing ability in relation to non-polar liquids. Hydrodynamic parameters of macromolecules of sodium alginate in comparison with macromolecules of chitosan correspond to the conformation of the loose ball. The state of the SN is determined by the pH of the medium and temperature. The increase in temperature leads to a violation of the structure of the chain, its destruction and a subsequent decrease in viscosity. At a temperature of 293K, the macromolecule is in a more ordered state. In the alkaline environment there is a change in the conformation of the macromolecule. As a result of this change, the viscosity naturally increases. This is explained by the fact that in an alkaline environment, the macromolecule acquires an excess negative charge, there is a repulsion of the carboxyl groups of the same name in the chain links. The macromolecule acquires an expanded configuration. The viscosity increases. In acidic environment, sodium alginate has almost zero charge as a result of protonation of carboxyl groups. The molecule acquires the conformation of a loose ball with the lowest value of viscosity. The isoelectric state of the alginate macromolecule is observed in the pH range of 5.5 to 6.0. The described state of the macromolecule in solution is confirmed by our calculations. The interaction of surface-active cations with carboxyl groups of SN leads first to the formation of associates, then to polymer-colloidal complexes. The association as a result of electrostatic interaction of active groups is enhanced by the hydrophobic interaction of hydrocarbon fragments of surfactant molecules with each other and with the alginate matrix. The association ends with the formation of a polymer-colloidal complex.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87085906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BUFFER SYSTEMS BASED ON AMINOMETANESULPHONATE AND MONOETHANOLAMMONIUM N-ALKYLAMINOMETHANESULPHONATES","authors":"R. Khoma, А. Ennan, T. Bienkovska, L. T. Osadchiy, E. L. Roy","doi":"10.18524/2304-0947.2021.2(78).233816","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.2(78).233816","url":null,"abstract":"The limits of the pH buffering action (pHbuff) of YNHCH2SO3H – NH2CH2CH2OH –H2O (Y = H, CH3, HOCH2CH2, t-С4H9 and C6H5CH2) were determined and their buffer capacity (p) for monoethanolamine (MEA) was estimated in the temperature range 293–313 K. For systems with aminomethanesulfonic acid (AMSA), its N‑methyl, N‑hydroxyethyl (HEAMSA) and N‑benzyl (BzAMSA) derivatives, an increase in temperature leads to a decrease in the pH values of the lower limit of the buffering action of their solutions with monoethanolamine; in the case of N‑tert-butylaminomethanesulfonic acid (t-BuAMSA) – to an increase in the specified characteristic. An increase in temperature for systems with the most hydrophobic t-BuAMSA and BzAMSA (in comparison with other studied aminomethanesulfonic acids) leads to a decrease in the pH values of the upper limit of the buffer action. A decrease in the YNHCH2SO3H and NH2CH2CH2OH concentration leads to a shift in the boundaries of the pH of the buffering action to a more acidic region. The nature of the influence of the empirical function, combining their acid-base properties and lipophilicity (рKа + lgPow), on the concentration dependence of the buffer capacity according to MEA was revealed. It is shown that the buffering effect of the studied systems is due to the presence, in addition to the systems N‑alkylammoniummethanesulfonate – N‑alkylaminomethanesulfonate and 2-hydroxyethylammonium – monoethanolamine, ionic associates (pairs and triples). The position of the extrema on the graphical π=f(CMEA)/QYAMSA) dependencies for systems with hydrophilic AMSA and HEAMSA coincides with the position of the first minima on the differential titration curves dpH/dV = f(CMEA)/QYAMSA). Substitution of MEA to potassium aminomethanesulfonate leads to a shift in the pH buffering action to a more acidic region and increases the buffer capacity of the resulting systems.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83064159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CVD-COMPOSITES AND SALINE SOLUTIONS-MELTS: SIMILARITY AND DIFFERENCES","authors":"V. Zinchenko, V. V. Menchuk","doi":"10.18524/2304-0947.2021.2(78).233813","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.2(78).233813","url":null,"abstract":"The general features and specific peculiarities of the thermodynamics of the processes occurring during the evaporation of CVD (Chemical Vapor Deposition) – composites based on germanium – metal chalcogenide systems and dissolution of poorly soluble compounds in salt melts are considered. The essence of both processes consists in the occurrence of exchange reactions between the initial components with the formation of highly volatile substances in the first case and highly soluble compounds in the second. Both processes are endothermic in their thermochemical essence, and their course is facilitated by the entropy component, the role of which increases with increasing temperature, deepening of the vacuum in the case of CVD composites, and dilution of the saline solution – melt. The peculiarities due to the difference between vacuum and salt melt in nature have also been established. If the interaction of molecules in a rarefied molecular vapor of evaporation products can be practically neglected, then in a salt solution-melt, as in a highly concentrated system, secondary reactions of complexation of ions and molecules of the dissolved compound and the main ions of the melt are characteristic. The latter factor significantly affects the solubility in the salt melt due to the shift in equilibrium. Kinetic factors, which differ significantly in both processes, are essential in the reverse reactions of condensation of a CVD‑composite vapor on a substrate and in the deposition of crystals during the crystallization of a solute from a salt melt. Due to the much higher rate of vapor condensation on the substrate, more significant vapor saturation is achieved and, accordingly, the nucleation rate than during crystallization of the salt melt. Therefore, the probability of nanostructuring or complete amorphization of a coating obtained from a CVD‑composite is much higher than for a salt solution-melt, in which the ability to form nanostructures is more limited.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90745514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SORPTION OF BISMUTON (III) IONS FROM AQUEOUS SOLUTIONS BY SILICAS MODIFIED BY ORGANIC REAGENTS","authors":"A. Chebotarev, D. Snigur, D. Barbalat, O. M. Rakhlytskaya, O. Zhukovetska, K. Snihur","doi":"10.18524/2304-0947.2021.2(78).233830","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.2(78).233830","url":null,"abstract":"In current paper, adsorbents based on silica L 40/100 modified with 4-(2-pyridylazo)resorcinol, 1-(2-pyrylazo)naphthol‑2, pyrocatechol violet and sodium N, N‑diethyldithiocarbamate were obtained. Adsorbents were modified by non-covalent immobilization of organic analytical reagents on the silica surface. It is noted that the preparation of such adsorbents is fast and easy to manufacture. The conditions of Bismuth (III) adsorption from dilute aqueous solutions by the proposed adsorbents are studied and optimized. The optimal values of the medium acidity for the effective Bismuth (III) preconcentration by the proposed adsorbents based on silica modified with organic analytical reagents have been established. It is shown that the use of modified silicas allows efficient (95–98%) removal of Bismuth (III) from dilute aqueous solutions. Under optimal adsorption conditions, the capacity of modified adsorbents is determined. It is established that the modification of silica leads to a significant (2–3 times) increase in the capacity of the obtained sorbents by Bismuth (III) in comparison with the unmodified silica, which is associated with the processes of complexation on the surface. The desorption of Bismuth (III) from the surface of unmodified and modified silicas by solutions of mineral acids has been studied. It is shown that Bi(III) is quantitatively desorbed from the surface of unmodified silicas by solutions of sulfuric and nitric acids, and in the case of modified silicas the degree of desorption is small and does not exceed 35%. The data obtained can then be used to develop a test system for determination of Bismuth (III) via corresponding colorimetric scales or for quantitative solid phase extraction and adsorption-spectroscopic quantification of Bismuth (III) in some real samples.\u0000 ","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73397606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COMPARATIVE CHARACTERISTICS OF COATINGS WITH SiO AND GeO ON LEUCOSAPPHIRE","authors":"V. Zinchenko, I. Magunov, O. V. Mozkova, B. A. Gorshteĭn, V. P. Sobol, L. V. Sadkovska","doi":"10.18524/2304-0947.2021.2(78).233815","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.2(78).233815","url":null,"abstract":"The reasons for the sharp difference in the adhesion of multilayer coatings containing SiO or GeO together with Ge on a leucosapphire (Al2O3) plate have been established. It should be mentioned that Silicon(II) and Germanium(II) oxides are quite stable in the gaseous state and, contrary, are metastable in condensed state; at high temperature they disproportionate into ultra-dispersed composites of amorphous nature. A comparison is made of the surface properties of ultramicroscopic droplets formed on solid surfaces – a substrate or the previous layer – upon condensation of SiO, GeO, or Ge vapors on leucosapphire. A qualitative assessment of the ratio of the corresponding contact angles of wetting by the indicated melts, formed at the first moment of contact, has been carried out. In assessing the surface tension of SiO and GeO melts (or Si – SiO2 and Ge – GeO2 composites), we proceeded from the corresponding values for SiO2 and GeO2, which are 296 and 248 mJ/m2 near the crystallization temperatures. On this basis, it was established that the smallest value of the contact angle, and hence the best wetting, is observed for the GeO melt (somewhat less for the SiO melt) on the solid surface of Al2O3 or Ge; the solid surface of SiO or GeO (especially, the first of them) with molten germanium should be much weaker wetted. Hence, it follows that thin-film multilayer coatings obtained from Ge and GeO on a leucosapphire substrate should have a significantly higher climatic resistance due to higher adhesion compared to multilayer coatings from SiO and Ge. Indeed, a multilayer coating containing SiO on a leucosapphire substrate with a large surface can withstand storage in air for no more than 2–3 months and begins to peel off; at the same time, the GeO coating remains intact after 4 years of storage. Thus, the GeO film-forming material is a promising one for use in multilayer coatings such as cut-off filters in interference optics of the near and mid-IR spectral ranges.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"106 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85557866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SORPTION-LUMINESCENT DETERMINATION OF OROTIC ACID IN MEDICINAL DRUGS","authors":"S. Beltyukova, O. Teslyuk, E. Liventsova","doi":"10.18524/2304-0947.2021.1(77).226138","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.1(77).226138","url":null,"abstract":"Luminescent properties of orotic acid (vitamin B13), known bioactive substance, have been evaluated in this research. It has been shown that inside a coordination complex of orotic acid with terbium (III) an intermollecular excitation energy transfer from a ligand to a lanthanide ion occurs which causes sensitization of terbium (III) ion luminescence. Intensity of the terbium (III) ion luminescence (ILum) increases in the presence of anionic and cationic surfaceactive agents as a result of displacement of water molecules from coordination sphere of the complex. As a consequence of this process, a non-radiative deactivation of excitation energy decreases and more efficient excitation energy transfer from a ligand to a lanthanide ion occurs. It has been established that after absorption of analyte of interest onto a polymer matrix of a solid phase extraction sorbent with subsequent increasing of its molecular rigidity more efficient excitation energy transfer is observed followed by elevation of luminescence (ILum) intensity of the coordination complex being studied. Intensity of luminescence of coordination complex of orotic acid with terbium (III) in the form of a sorbate salt has been estimated involving different types of sorbents (Phosphalugel, SFG-75, Calflo E, Celite 545, Silicagel Merck). Most suitable results have been achieved by the use of Silica gel Merck as a solid-phase matrix (sorbent). The removal rate of the complex from the solution in this case reaches to 97%. The most effective conditions for determination of orotic acid have been specified. The highest values of luminescence intensity is obtained by conducting of sorption using 5 mL of solution and 100 mg of sorbent. Luminescence intensity of the complex in the form of a sorbate salt, during a sorption process, increases in presence of ethonium, cationic dimeric surface-active agent. Decrease in luminescence intensity of the complexes in the form of a sorbate salt in presence of other surface-active agents may be caused by solubilization of the complex in the solution and thereby reduced level of its sorption. On the basis of presented research work a new analytical procedure has been developed for the solid-phase luminescence determination of orotic acid and orotic acid salts in pharmaceutical drugs. Determination of orotic acid salts has been performed in pharmaceutical drugs ‘Magnerot’ (magnesium orotate) and ‘Potassium orotate’. The proposed analytical procedure for determination of orotic acid salts is remarkable by good metrological characteristics and relative simplicity of performance. The relative standard deviation, Sr, is 3,6 - 4,3%.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81064904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BUFFER SOLUTIONS BASED ON TAURINE","authors":"T. S. Ben’kovs’ka, R. Khoma, A. Chebotaryov, A. Ennan, L. T. Osadchiy","doi":"10.18524/2304-0947.2021.1(77).226146","DOIUrl":"https://doi.org/10.18524/2304-0947.2021.1(77).226146","url":null,"abstract":"The acid-base interaction in the aminoethanesulfonic acid (taurine, Tau) – potassium aminoethanesulfonate – water system was studied by pH-, redox- and conductometric methods in the temperature range 293–313 K. The ion-molecular composition of NH2CH2CH2SO3H –NH2CH2CH2SO3K – H2O system was calculated. It is shown aminoethanesulfonic acid in aqueous solutions to exist at the ratio CKOH/QTau < 0.5 mainly in the zwitterion form similar to systems with glycine, aminomethanesulfonic acid and its N‑alkylated derivatives. The content of the aminoethanesulfonate anion is directly proportional to the CKOH/QGly ratio. The studied system ionic strength and acid-base dissociation constant for the second stage of the aminoethanesulfonic acid concentration and temperature dependences were determined. The ionic strength values at the isoelectric point (mi.p.)are directly proportional to С0Tau and practically do not depend on the temperature within the error for the same series С0Tau and С0KOH .The pH limits of the buffer action are determined and the buffer capacity of these systems is estimated. It has been established that effective buffer zones of Tau aqueous solutions can to maintain acidity in the higher then physiological pH range at temperature range 293–313 K. The buffer capacity of NH2CH2CH2SO3H – NH2CH2CH2SO3K – H2O system exceeds the analogous values of YNHCH2SO3H – YNHCH2SO3K – H2O (Y = H, CH3, CH2CH2OH, C(CH3)3 and C2H5C6H5) systems. The obtained data on the buffer capacity of the aminoethanesulfonic acid – potassium aminoethanesulfonate – water system can be used in chemical analysis, microbiological and biochemical studies, and the acidity data of the solutions studied can simulate the chemisorption of acid gases (carbon and sulfur dioxides).","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84390439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}