Physico-chemical properties of electron-acceptor stationary phases in liquid chromatography

1992 ◽  
Vol 591 (1-2) ◽  
pp. 75-88 ◽  
Author(s):  
Kenneth J. Welch ◽  
Norman E. Hoffman
Keyword(s):  
Liquid Chromatography ◽  
Electron Acceptor ◽  
Stationary Phases ◽  
Chemical Properties ◽  
Physico Chemical

Ionic Liquids in Analytical Chemistry: Applications and Recent Trends

2021 ◽  
Vol 17 ◽  
Author(s):  
Giuseppe Maria Merone ◽  
Angela Tartaglia ◽  
Enrica Rosato ◽  
Cristian D’Ovidio ◽  
Abuzar Kabir ◽  
...  
Keyword(s):  
Analytical Chemistry ◽  
Ionic Liquids ◽  
Stationary Phases ◽  
Extraction Procedure ◽  
Chemical Properties ◽  
Electrochemical Analysis ◽  
Physico Chemical ◽  
Recent Trends ◽  
Number Of Publications ◽  
Physical And Chemical

Background: Ionic liquids (ILs) are a unique class of compounds consisting exclusively of cations and anions that possess distinctive properties such as low volatility, high thermal stability, miscibility with water and organic solvents, electrolytic conductivity and non-flammability. Ionic liquids have been defined as "design solvents", because it is possible to modify their physical and chemical properties by appropriately choosing cations and anions, in order to meet the specific characteristics based on their potential application. Introduction: Due of their tunable nature and properties, ILs are considered as the perfect candidates for numerous applications in analytical chemistry including sample preparation, stationary phases in liquid or gas chromatography, additives in capillary electrophoresis, or in mass spectrometry for spectral and electrochemical analysis. In the last years, the number of publications regarding ILs has rapidly increased, highlighting the broad applications of these compounds in various fields of analytical chemistry. Results: This review first described the main physico-chemical characteristics of ionic liquids, and subsequently reported the various applications in different subdisciplines of analytical chemistry, including the extraction procedure and separation techniques. Furthermore, in each paragraph the most recent applications of ionic liquids in the food, environmental, biological, etc. fields have been described. Conclusion: Overall, the topic discussed highlights the key role of ionic liquids in analytical chemistry, giving hints for their future applications in chemistry but also in biology and medicine.

Liquid Chromatography in Migration Studies

1981 ◽  
Vol 11 ◽  
Author(s):  
Lars Carlsen ◽  
Walther Batsberg
Keyword(s):  
Liquid Chromatography ◽  
Radioactive Waste ◽  
Experimental Technique ◽  
Chemical Properties ◽  
Detailed Knowledge ◽  
Geochemical Environment ◽  
Physico Chemical ◽  
The Media ◽  
A Site ◽  
Sorption Characteristics

A detailed knowledge of the geochemical environment of a site for the disposal of radioactive waste is of fundamental importance. To evaluate the migration behaviour of radionuclides in geological media a series of data are needed, amongst others a number of physico-chemical properties of the media, such as permeability, porosity, dispersion-, diffusion-, and sorption characteristics. In this connection liquid chromatography appears to be advantageous as a facile experimental technique to obtain relevant data for these physico-chemical properties.

ChemInform Abstract: Physico-Chemical Properties of Micro-Spherical Silica Gel for High- Performance Liquid Chromatography.

ChemInform ◽  
2010 ◽  
Vol 24 (25) ◽  
pp. no-no
Author(s):  
N. V. ZHURAVLEVA ◽  
K. I. SAKODYNSKII ◽  
M. A. KUKLINA ◽  
V. M. KUKLIN ◽  
N. N. SUKHANOV
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Silica Gel ◽  
High Performance ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Spherical Silica

scholarly journals The Fatty Acid Composition and Properties of Oil Extracted from Seeds of Carum roxburghianum Benth. (Radhuni)

1970 ◽  
Vol 46 (1) ◽  
pp. 111-116
Author(s):  
BK Paul ◽  
MN Ahmed ◽  
GC Saha
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Liquid Chromatography ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Acid Composition ◽  
Unsaturated Fatty Acids ◽  
Chemical Properties ◽  
Gas Liquid Chromatography ◽  
Physico Chemical

Carum roxburghianum Benth. (Radhuni) seeds of three different places of Bangladesh were investigated to determine the fatty acid composition and physico-chemical properties of extracted oil. The seeds were found to contain oil ranging from 15.31 to 20.32%. The percentage compositions of fatty acids were identified and quantified by Gas Liquid Chromatography (GLC). The saturated and unsaturated fatty acids in extracts were 4.95 to 6.27% and 93.73 to 94.89%, respectively. Among six fatty acids identified in this study, oleic acid contributed the highest portion (76.44 to 79.16%), whereas, linoleic (1.38%), linolenic (15.28 - 15.40%), stearic (0.70%), palmitic (4.95 - 5.57%) and ecosenoic acid (0.51 - 15.73%) together contributed the rest. Physico-chemical properties of the oil extracted were also investigated. The specific gravity, refractive index, optical rotation were recorded as 0.903 to 0.918 at 30°C, 1.465 to 1.470 at 30°C and +8.54° to +9.56° at 26°C, respectively. The chemical properties like saponification value (183.52 - 193.45), iodine value (80.99 - 120.90), peroxide value (23.25 - 36.16), acid value (143.84 - 162.99), ester value (48.12 - 62.03), percentage of unsaponifiable matter (3.56 - 6.51%), Reicher-Meissel value (2.00 - 3.12), Polenske value (4.12 - 6.20) and Henher value (85.12 - 95.56) were determined. Overall Radhuni seeds oil can be considered as a good source of oleic acid. Keywords: Carum roxburghianum; Radhuni seed oil; fatty acid composition; oleic acid; Gas Liquid Chromatography. DOI: http://dx.doi.org/10.3329/bjsir.v46i1.8113 Bangladesh J. Sci. Ind. Res. 46(1), 111-116, 2011

scholarly journals DynaStI: A Dynamic Retention Time Database for Steroidomics

Metabolites ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 85 ◽  
Author(s):  
Santiago Codesido ◽  
Giuseppe Marco Randazzo ◽  
Fabio Lehmann ◽  
Víctor González-Ruiz ◽  
Arnaud García ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Metabolic Pathways ◽  
Structural Information ◽  
Chemical Properties ◽  
Reversed Phase ◽  
Liquid Chromatography Mass Spectrometry ◽  
Phase Gradient ◽  
Physico Chemical ◽  
Solvent Strength ◽  
Reversed Phase Lc

Steroidomics studies face the challenge of separating analytical compounds with very similar structures (i.e., isomers). Liquid chromatography (LC) is commonly used to this end, but the shared core structure of this family of compounds compromises effective separations among the numerous chemical analytes with comparable physico-chemical properties. Careful tuning of the mobile phase gradient and an appropriate choice of the stationary phase can be used to overcome this problem, in turn modifying the retention times in different ways for each compound. In the usual workflow, this approach is suboptimal for the annotation of features based on retention times since it requires characterizing a library of known compounds for every fine-tuned configuration. We introduce a software solution, DynaStI, that is capable of annotating liquid chromatography-mass spectrometry (LC–MS) features by dynamically generating the retention times from a database containing intrinsic properties of a library of metabolites. DynaStI uses the well-established linear solvent strength (LSS) model for reversed-phase LC. Given a list of LC–MS features and some characteristics of the LC setup, this software computes the corresponding retention times for the internal database and then annotates the features using the exact masses with predicted retention times at the working conditions. DynaStI (https://dynasti.vital-it.ch) is able to automatically calibrate its predictions to compensate for deviations in the input parameters. The database also includes identification and structural information for each annotation, such as IUPAC name, CAS number, SMILES string, metabolic pathways, and links to external metabolomic or lipidomic databases.

Surface Energy of Silica Xerogels and Fumed Silica by Inverse Gas Chromatography and Inverse Liquid Chromatography

2002 ◽  
Vol 75 (5) ◽  
pp. 811-824 ◽  
Author(s):  
J. B. Donnet ◽  
Y. J. Li ◽  
T. K. Wang ◽  
H. Balard ◽  
G. T. Burns
Keyword(s):  
Gas Chromatography ◽  
Surface Modification ◽  
Liquid Chromatography ◽  
Surface Energy ◽  
Fumed Silica ◽  
Inverse Gas Chromatography ◽  
Chemical Properties ◽  
Silica Xerogels ◽  
Silica Surfaces ◽  
Physico Chemical

Abstract Inverse gas chromatography (IGC) and inverse liquid chromatography (ILC) have been used to detect the interaction energy between silicas (fumed silicas and silica xerogels) surfaces and probes molecules. The silica surfaces were modified chemically by trimethylsiloxane functions. Either IGC or ILC have detected the adsorption energy change following the surface modification. In IGC technique, the results with several probes show clearly the physico-chemical properties of the silica surfaces. ILC was developed to use bigger probe molecules which are more similar in structure to polymers. In this work, squalene, a non volatile molecule with 30 carbon atoms and several double bonds, was used in ILC to simulate elastomer molecules.

scholarly journals Enantioselective Liquid Chromatographic Separations Using Macrocyclic Glycopeptide-Based Chiral Selectors

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3380
Author(s):  
Róbert Berkecz ◽  
Dániel Tanács ◽  
Antal Péter ◽  
István Ilisz
Keyword(s):  
Liquid Chromatography ◽  
Stationary Phases ◽  
Practical Importance ◽  
Food Additives ◽  
Chemical Properties ◽  
Chiral Stationary Phases ◽  
Glycopeptide Antibiotics ◽  
Enantiomeric Separations ◽  
Chiral Selectors ◽  
Macrocyclic Glycopeptide

Numerous chemical compounds of high practical importance, such as drugs, fertilizers, and food additives are being commercialized as racemic mixtures, although in most cases only one of the isomers possesses the desirable properties. As our understanding of the biological actions of chiral compounds has improved, the investigation of the pharmacological and toxicological properties has become more and more important. Chirality has become a major issue in the pharmaceutical industry; therefore, there is a continuous demand to extend the available analytical methods for enantiomeric separations and enhance their efficiency. Direct liquid chromatography methods based on the application of chiral stationary phases have become a very sophisticated field of enantiomeric separations by now. Hundreds of chiral stationary phases have been commercialized so far. Among these, macrocyclic glycopeptide-based chiral selectors have proved to be an exceptionally useful class of chiral selectors for the separation of enantiomers of biological and pharmacological importance. This review focuses on direct liquid chromatography-based enantiomer separations, applying macrocyclic glycopeptide-based chiral selectors. Special attention is paid to the characterization of the physico-chemical properties of these macrocyclic glycopeptide antibiotics providing detailed information on their applications published recently.

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