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.

Quantitative Evaluation of Polarity of Silica Gel Modified with Transition Metals Chelates for Gas Chromatography

2015 ◽  
Vol 670 ◽  
pp. 246-251 ◽  
Author(s):  
Aleksandra I. Makarycheva ◽  
Yury G. Slizhov
Keyword(s):  
High Selectivity ◽  
Complex Structure ◽  
Chemical Properties ◽  
Silica Gels ◽  
Solvation Parameter Model ◽  
Physico Chemical ◽  
Gas Chromatographic Separation ◽  
Solvation Parameter ◽  
Sorption Characteristics ◽  
Modified Silica Gels

New packings based on Silochrome C80 modified with Cu (II), Co (II) and Ni (II) 8-oxyquinolinates were studied. Their sorption characteristics and chromatographic properties were investigated and the comparative evaluation of sorbents polarity was carried out by applying Rohrschneider-McReynolds coefficients system, thermodynamic data and using the solvation parameter model of Abraham. It was found that the nature of metal and complex structure have a decisive influence on the physico-chemical properties of the packings. Modified silica gels show high selectivity for gas chromatographic separation of oxygen containing and aromatic organic compounds.

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

Altered Crystalline Rock Distributed Along Groundwater Conductive Fractures and the Retardation Capacity in the Orogenic Field of Japan

2009 ◽  
Author(s):  
Hidekazu Yoshida ◽  
Shoji Nishimoto ◽  
Richard Metcalfe
Keyword(s):  
Radioactive Waste ◽  
Barrier Function ◽  
Chemical Characterization ◽  
Crystalline Rock ◽  
Crystalline Rocks ◽  
Rock Interaction ◽  
Physico Chemical ◽  
High Level ◽  
A Site ◽  
Accessible Porosity

In the orogenic field Japanese islands, there are wide areas of crystalline rocks that inevitably contain groundwater conductive fractures associated with alteration zones. However, little attention has been given to the formation process and possible influence on the radionuclides migration from radioactive waste repository that might be sited within crystalline rock. In particular, the influences of alteration minerals and microfractures, due to chemical sorption and/or physical retardation are required to assess the realistic barrier function. In order to understand the alteration process and the retardation capacity, detailed mineralogical and physico-chemical characterization of altered crystalline rocks have been carried out. Mineralogical analysis reveals that the altered crystalline rocks have been formed through basically two stages of water-rock interaction during and after uplift. Physico-chemical characteristics including laboratory sorption experiments show that altered crystalline rock has a certain volume of accessible porosity, particularly in plagioclase grains, which would influence on nuclide retardation more than the accessible porosity in other minerals present, such as biotite. These results provide confidence that even altered and fractured parts of any crystalline rock that might be encountered in a site for the disposal of high-level radioactive waste may still play a role of barrier function.

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 Simultaneous Control of NOx-Soot by Substitutions of Ag and K on Perovskite (LaMnO3) Catalyst

2018 ◽  
Vol 13 (1) ◽  
pp. 144 ◽  
Author(s):  
Ganesh Chandra Dhal ◽  
Subhashish Dey ◽  
Devendra Mohan ◽  
Ram Prasad
Keyword(s):  
Nox Reduction ◽  
Chemical Properties ◽  
Metallic Silver ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Perovskite Catalyst ◽  
Structured Catalysts ◽  
Simultaneous Control ◽  
Physico Chemical ◽  
A Site

The different Ag and K substituted perovskite catalysts including base catalyst were LaMnO3 by the solid state method and the diesel soot was prepared in the laboratory. Their structures and physico-chemical properties were characterized by X-ray diffraction (XRD), BET, SEM, H2-TPR, and XPS techniques. The Ag Substituted at A-site perovskite structured catalysts are more active than other type of catalysts for the simultaneous soot-NOX reaction, When Ag and K are simultaneously introduced into LaMnO3 catalyst, soot combustion is largely accelerated, with the temperature (Tm) for maximal soot conversion lowered by at least 50 °C, moreover, NOX reduction by soot is also facilitated. The high activity of La0.65Ag0.35MnO3 perovskite catalyst is attributed to presence of metallic silver in the catalyst. The activity order of Ag doped LaMnO3 is as follows La0.65Ag0.35MnO3 > La0.65Ag0.2MnO3 > La0.65Ag0.4MnO3 > La0.65Ag0.1MnO3. The dual substitution of silver and potassium in place of La in LaMnO3 gives better activity than only silver doped catalyst. In a series of La0.65AgxK1-xMnO3, the optimum substitution amount of K is for x=0.25. The single and doubled substituted perovskite catalyst proved to be effective in the simultaneous removal of NOX and soot particulate, the two prevalent pollutants in diesel exhaust gases in the temperature range 350-480 °C. Copyright © 2018 BCREC Group. All rights reservedReceived: 19th July 2017; Revised: 8th September 2017; Accepted: 8th September 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018How to Cite: Dhal, G.C., Dey, S., Mohan, D., Prasad, R. (2018). Simultaneous Control of NOx-Soot by Substitutions of Ag and K on Perovskite (LaMnO3) Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 144-154 (doi:10.9767/bcrec.13.1.1152.144-154)

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.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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