scholarly journals Application of Hydrophilic Interaction Liquid Chromatography for the Quantification of Flavonoids inGenista tinctoriaExtract

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Aleksandra Sentkowska ◽  
Magdalena Biesaga ◽  
Krystyna Pyrzynska
Keyword(s):  
Mobile Phase ◽  
Retention Mechanism ◽  
Chromatographic Behavior ◽  
Hydrophilic Interaction ◽  
Silica Column ◽  
Retention Factors ◽  
Component Content ◽  
Chromatographic Procedure ◽  
Unmodified Silica ◽  
Genista Tinctoria

Hydrophilic interaction chromatography (HILIC) was employed to investigate chromatographic behavior of selected flavonoids from their different subgroups differing in polarity. Chromatographic measurements were performed on two different HILIC columns: unmodified silica (Atlantis-HILIC) and zwitterionic sulfoalkylbetaine (SeQuant ZIC-HILIC). Separation parameters such as content and type of organic modifier were studied. On ZIC column retention factors were observed to be inversely proportional to the buffer content in the mobile phase, which is the typical partitioning mechanism. In the case of bare silica column more or less apparent dual retention mechanism was observed, depending on the water component content in the mobile phase. ZIC-HILIC showed better selectivity (in comparison to silica column) with the detection limit of 0.01 mg/L (only for rutin was 0.05 mg/L). Finally, this chromatographic procedure was validated and applied for the determination of some flavonoids inGenista tinctoriaL. extract.

scholarly journals Estimation of Solute-Stationary Phase and Solute-Mobile Phase Interactions in the Presence of Ionic Liquids

Separations ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 40
Author(s):  
María José Ruiz-Ángel
Keyword(s):  
Ionic Liquids ◽  
Stationary Phase ◽  
Mobile Phase ◽  
Stationary Phases ◽  
Reversed Phase ◽  
Retention Mechanism ◽  
Chromatographic Behavior ◽  
Chemical Equilibria ◽  
Suppression Effect ◽  
Mobile Phases

The presence of free silanols on alkyl-bonded reversed-phase stationary phases is responsible for broad and asymmetrical peaks when basic drugs are chromatographed with conventional octadecylsilane (C18) columns due to ionic interactions. In the last few years, ionic liquids (ILs) have attracted attention to reduce this undesirable silanol activity. ILs should be considered as dual modifiers (with a cationic and anionic character), which means that both cations and anions are able to adsorb on the stationary phase, creating a positively or negatively charged layer, depending on the relative adsorption. The accessibility of basic compounds to the silanols is prevented by both the IL cation and anion, improving the peak profiles. A comparative study of the performance of six imidazolium-based ILs, differing in their cation/anions, as modifiers of the chromatographic behavior of a group of ten β-adrenoceptor antagonists, is addressed. Mobile phases containing cationic amines (triethylamine and dimethyloctylamine) were used as a reference for the interpretation of the results. Using a mathematical model based on two chemical equilibria, the association constants between the solutes and modified stationary phase as well as those between solutes and the additive in the mobile phase were estimated. These values, together with the changes in retention and peak shape, were used to obtain conclusions about the retention mechanism, changes in the nature of the chromatographic system, and silanol suppression effect.

Hydrophilic Interaction Liquid Chromatography and Per Aqueous Liquid Chromatography in Fungicides Analysis

2012 ◽  
Vol 95 (5) ◽  
pp. 1362-1370 ◽  
Author(s):  
Sylwia Noga ◽  
Attila Felinger ◽  
Bogusław Buszewski
Keyword(s):  
Liquid Chromatography ◽  
Organic Solvent ◽  
Mobile Phase ◽  
Retention Mechanism ◽  
Operating Conditions ◽  
Biologically Active ◽  
Hydrophilic Interaction Liquid Chromatography ◽  
Hydrophilic Interaction ◽  
Active Compounds ◽  
Retention Mechanisms

Abstract The goal of the study was to investigate the retention mechanism of selected fungicides in hydrophilic interaction liquid chromatography (HILIC) and per aqueous liquid chromatography (PALC). Chromatographic measurements were made on four physicochemically diversified HILIC columns, which were evaluated for the analysis of nine biologically active compounds, such as strobilurins and triazoles. The effects of the operating conditions on separations were investigated, including the concentration of the organic solvent in the aqueous-organic (acetonitrile) mobile phase. The results were compared, and it was shown that two different retention mechanisms dominate in PALC at low acetonitrile concentrations and in HILIC at high acetonitrile concentrations.

scholarly journals Determination of Rocuronium bromide by hydrophilic interaction liquid chromatography (HILIC)

2001 ◽  
Vol 57 ◽  
pp. 17-24 ◽  
Author(s):  
Natalija Nakov ◽  
Rumenka Petkovska ◽  
Liljana Ugrinova ◽  
Suzana Trajkovic-Jolevska ◽  
Aneta Dimitrovska
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Ph Value ◽  
Degradation Products ◽  
Hydrophilic Interaction Liquid Chromatography ◽  
Hydrophilic Interaction ◽  
Rocuronium Bromide ◽  
Silica Column ◽  
Chromatographic Parameters

A new method involving hydrophilic interaction liquid chromatography (HILIC) has been developed for determination of rocuronium bromide in presents of its main impurities (impurity A and impurity C), which are also its main degradation products, in solution for injection. The influence of the critical chromatographic parameters such as content of acetonitrile in the mobile phase, ionic strength and pH value of the buffer used in the mobile phase were investigated using the Design of experiments approach (DoE). The mechanism of retention of rocuronium bromide on bare silica column was also investigated. Optimal chromatographic conditions were obtained using mixture of acetonitrile and ammonium formate (107.5mM, pH 7.0) in ratio 90:10 as a mobile phase. The validation results have shown that the method is suitable for determination of rocuronium bromid in solution for injection.

scholarly journals Development and Validation of Retention Models in Supercritical Fluid Chromatography for Impregnation Process Design

2021 ◽  
Vol 11 (15) ◽  
pp. 7106
Author(s):  
Miaotian Sun ◽  
Zeynep Ülker ◽  
Zhixing Chen ◽  
Sivaraman Deeptanshu ◽  
Monika Johannsen ◽  
...  
Keyword(s):  
Supercritical Fluid ◽  
Supercritical Fluid Chromatography ◽  
Stationary Phases ◽  
Retention Factor ◽  
Retention Mechanism ◽  
Retention Data ◽  
Retention Models ◽  
Retention Factors ◽  
Polar Solutes ◽  
Porous Matrices

The retention factor is the key quantity for the thermodynamic analysis of the retention mechanism in chromatographic experiments. In this work, we measure retention factors for moderately polar solutes on four silica-based porous matrices as stationary phases by supercritical fluid chromatography. Elution of the solutes is only possible with binary mixtures of supercritical carbon dioxide (sc-CO2) and modifier (methanol) due to the low polarity of pure sc-CO2. The addition of modifiers makes the retention mechanism more complex and masks interactions between solute and stationary phase. In this work, we develop and validate several retention models that allow the obtaining of retention factors in modifier-free sc-CO2. Such models pave the way for quantifying adsorption interactions between polar solutes and non-swellable porous matrices in pure sc-CO2 based on retention data obtained in sc-CO2/modifier mixtures. The obtained information will thereby facilitate the understanding and design of impregnation processes, which are often performed in modifier-free conditions.

scholarly journals Retention behaviour of acyclic polyfunctional D-arabinose derivatives

2002 ◽  
pp. 35-44 ◽  
Author(s):  
Ljiljana Kolarov ◽  
Eva Loncar ◽  
Radomir Malbasa
Keyword(s):  
Mobile Phase ◽  
Volume Fraction ◽  
Retention Mechanism ◽  
Biologically Active ◽  
Polar Component ◽  
Chiral Molecules ◽  
Retention Behaviour ◽  
Polar Components ◽  
Solute Retention ◽  
Mobile Phases

It is well known that some of biologically active compounds are chiral molecules. Natural monosaccarides are applicable as chiral precursors. D-arabinose is an appropriate chiral precursor in the synthesis of very important biomolecules such as biotin and its analogues and feromon )-exobrevicomin. Acyclic poly functional D- arabinose derivatives are intermediates in the synthesis of the former biomolecules. This paper deals with the retention behaviour and retention mechanism of acyclic poly functional D-arabinose derivatives. The tested compounds have been chromato graphed on silica gel thin layer using binary organic mobile phases with a different polarity. With increasing polarity of the eluent polar components the solute retention is decreasing. The linear relationship is obtained between the values of retention constant, RM' and the logarithm of the mobile phase polar component volume fraction for all solutes tested and eluents used.

scholarly journals Reversed-phase thin-layer chromatography behavior of aldopentose derivatives

2012 ◽  
Vol 66 (3) ◽  
pp. 365-372 ◽  
Author(s):  
Dragana Livaja-Popovic ◽  
Eva Loncar ◽  
Lidija Jevric ◽  
Radomir Malbasa
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Stationary Phases ◽  
Reversed Phase ◽  
Chromatographic Behavior ◽  
Log P ◽  
Retention Factors ◽  
Mobile Phases ◽  
Acetone Water ◽  
Layer Chromatography

Quantitative structure-retention relationships (QSRR) have been used to study the chromatographic behavior of some aldopentose. The behavior of aldopentose derivatives was investigated by means of the reversed-phase thin-layer chromatography (RP TLC) on the silica gel impregnated with paraffin oil stationary phases. Binary mixtures of methanol-water, acetone-water and dioxane-water were used as mobile phases. Retention factors, RM0, corresponding to zero percent organic modifier in the aqueous mobile phase was determined. Lipophilicity C0 was calculated as the ratio of the intercept and slope values. There was satisfactory correlation between them and log P values calculated using different theoretical procedures. Some of these correlations offer very good predicting models, which are important for a better understanding of the relationships between chemical structure and retention. The study showed that the hydrophobic parameters RM0 and C0 can be used as a measures of lipophilicity of investigated compounds.

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