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Information × Registration Number 0308U001478, 0106U003109 , R & D reports Title Control of interfacional processes and optimization of conditions in hybrid methods of chemical analysis popup.stage_title Характеристики поверхні модифікованих стаціонарних фаз у міцелярній рідинній хроматографії і моделювання утримання в МРХ. Head Loginova Lidiya Pavlovna, Registration Date 05-02-2008 Organization Kharkov national university named after V.N. Karazin popup.description2 The purpose of work: to obtain the peculiarities of surface state of reversed-phase alkylsilica sorbent modified by surfactant and organic additives and quantitative characterize the differences between microaggregates of surfactant in micellar eluent and on the surface of stationary phase. Methods: spectrophotometry with acid-base and solvatochromic probes, spectroscopy of diffuse reflection, ionometry with dodecylsulphate anion selective electrodes, electronic scanning microscopy. Obtained results and novelty: different character of modification of stationary phase surface of octadecylsilica by micellar eluent components at the temperature up to and higher the temperature of the phase transfer of grafted layer of alkyl radicals was shown for the first time by set of investigation methods of octadecylsilica suspension in micellar solutions of sodium dodecylsulphate (SDS). The mechanism of separation in micellar liquid chromatography (MLC) is determined by liquid-liquid distribution of substances and components of micellar eluent between mobile phase and modified "melted" grafted layer C18 at temperatures higher than 30 0С. At more low temperatures sorption of SDS of the surface of stationary phase of octadecylsilica are accompanied by formation of surface aggregates with lower values of critical micelle concentration, than for SDS micelles in solution. For the first time it was found using electronic scanning microscopy that sorption of SDS on C18 particles is promoted their attraction and agglutination; this effect can be eliminated by addition of 1-pentanol in SDS solution and increasing the temperature. The effects being discovered allow us to explain the peculiarities of MLC-separation efficiency. Results of the work can be used for further improvement of retention model in MLC, more accurate description of chromatographic processes and for control of separating processes in hybrid methods of analysis. Product Description popup.authors popup.nrat_date 2020-04-02 Close