ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Liquid chromatography  (7)
  • Gas-solid chromatography  (5)
  • thermodynamic properties  (5)
  • Chemistry
  • Springer  (17)
Collection
Keywords
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Physico-chemical applications of liquid chromatography II. Investigations of the surface properties of chemically modified silica gels and of the adsorption of cardiac glycosides from solutions (1981)
    Springer
    Chromatographia 14 (1981), S. 13-18 
    Details
    ISSN: 1612-1112
    Keywords: Chemical modification of silica ; Liquid chromatography ; Cardiac glycosides ; Chromatographic investigation of adsorption from solution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The chemical modification of silica surface using dichlorosilanes with methyl and phenyl groups and triethylamine as donor in the liquid phase was investigated. This modification leads to a dense coverage of the silica surface by the organic functional groups. Liquid chromatography permits the determination of the thermodinamic characteristics of intermolecular interactions of different molecules during adsorption from solutions on the modified surface of the silica. Silica gels modified with dichlorosilanes containing phenyl groups, possess high selectivity (α) and capacity (k′) for the cardiac glycosides G-strophanthin, K-strophanthoside, K-strophanthin-β and cymarin using water-alcohol mixture as the mobile phase, and the selectivity and capacity is much higher than observed on silica gels modified with methyl groups only.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02262056
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Regularities in the retention of isomeric aromatic hydrocarbons in liquid chromatography II. Analysis of polymethyl- and monoalkylbenzenes on silanized silica gel (1981)
    Springer
    Chromatographia 14 (1981), S. 638-640 
    Details
    ISSN: 1612-1112
    Keywords: Liquid chromatography ; Aromatic hydrocarbons ; Molecular structure ; Influence on retention
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The regularities of the retention of polymethyl- and monoalkylbenzenes on a nonpolar adsorbent (silanized silica gel) with a polar eluent (2∶3 isopropanol-water) have been studied. In contrast to the retention of the same compounds on a polar adsorbent (silica gel with hydroxylated surface) and with a nonpolar eluent (hexane) polymethylbenzenes are retained on silanized silica gel for a shorter time than the corresponding monoalkylbenzene isomers. The retention order of tert.-, sec.- and n-butylbenzenes is the reverse of that observed on silica gel having a hydroxylated surface. The retention order of xylenes, trimethyl- and tetramethylbenzenes is also the reverse of their retention order on silica gel having a hydroxylated surface. All the mixtures of the corresponding homologues and isomers have been separated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02291103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Gas chromatographic study of adsorption of nitrogen-containing organic compounds on graphitized thermal carbon black (1981)
    Springer
    Chromatographia 14 (1981), S. 478-483 
    Details
    ISSN: 1612-1112
    Keywords: Gas-solid chromatography ; Graphitized thermal carbon black ; Thermodynamics of adsorption ; Nitrogen compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary To study the role of the nitrogen atom in various valence states in the adsorption of nitrogen-containing molecules on the surface of hydrogen-treated graphitized thermal carbon black (HGTCB) gas chromatography was applied to determine the thermodynamic characteristics of adsorption: Henry's constants and heats of adsorption at zero surface coverage of nitriles, amines and indols on HGTCB. Adsorption characteristics of nitrogen-containing organic compounds and corresponding hydrocarbons are compared. It is shown that the logarithm of the retention volume and the heat of adsorption of n-alkylamines and n-alkylnitriles linearly depend on the number of carbon atoms in the molecule and on the average polarisability of the molecule. Relationship has been established between the Henry's constant as well as the heat of adsorption and the geometry of the molecule's disposition on HGTCB surface. Examples are given for the separation of a number of amines on the basis of the geometry of their molecules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02263538
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Retention of diphenyls, terphenyls, phenylalkanes and fluorene on graphitized thermal carbon black (1981)
    Springer
    Chromatographia 14 (1981), S. 510-514 
    Details
    ISSN: 1612-1112
    Keywords: Gas-solid chromatography ; Graphitized carbon black ; Aromatic hydrocarbons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This paper defines values of retention volumes for zero surface coverage (Henry's constant) at different temperatures, retention indices and variations of the internal energy (differential heats of adsorption) of diphenyl and its alkyl derivatives, terphenyls, diphenylmethane, triphenylmethane, diphenylethanes and fluorene on graphitized thermal carbon black (GTCB). Adsorption on GTCB takes place in accordance with the geometry of these molecules, the strongest adsorption being observed for para-terphenyl with least inhibited internal rotation of the molecule, while the weakest adsorption occurs for 2,6,2′,6′-tetramethyldiphenyl with the most inhibited internal rotation of the molecules. The flat molecules of fluorene are adsorbed on GTCB more readily than the nonflat molecules of diphenylmethane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02265630
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Intermolecular interactions in liquid adsorption chromatography (1983)
    Springer
    Chromatographia 17 (1983), S. 143-148 
    Details
    ISSN: 1612-1112
    Keywords: Liquid chromatography ; Intermolecular interactions ; Adsorption from solutions ; Chemically modified layers in LC ; Conformation of bonded chains
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary For the investigation of intermolecular interactions in adsorption from solution, which are the basis of selectivity in molecular liquid chromatography (LC), it is convenient to use the LC method itself. Using this method the Henry's constants, K1, and other thermodynamic adsorption characteristics of hydrocarbons and of a series of polar substances on hydroxylated silica surface were determined from aqueous solutions. On the basis of the adsorption of hydrocarbons from water solutions the structure of the chemically modifying layers formed by different hydrocarbon groups on the silica surface is considered. The role of conformation ability of straight-chain bonded phases is demonstrated. Hydrocarbons are adsorbed on the hydroxylated silica surface more strongly from aqueous solutions than from solutions in saturated hydrocarbons and their retention increases with the increase in the number of carbon atoms in the molecule. The retention in LC is determined by the intermolecular interaction of the solute and solvent molecules with the adsorbent, as well by the contribution of the intermolecular interaction, between the solute and the solvent. The thermodynamic characteristics of adsorption of cymarin from water-ethanol solutions on hydroxylated silica gel and on silica gel surface modified by diphenylsilyl groups is compared. The solubility of silica gel modified by diphenylsilyl groups at different composition of water-ethanol eluent at different temperatures is investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02271037
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Crossover equation of state for the thermodynamic properties of mixtures of methane and ethane in the critical region (1996)
    Springer
    International journal of thermophysics 17 (1996), S. 909-944 
    Details
    ISSN: 1572-9567
    Keywords: critical phenomena ; equation of state ; ethane ; methane ; plait point ; thermodynamic properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present an equation of state for the thermodynamic properties of mixtures of methane and ethane in the critical region that incorporates the crossover from singular thermodynamic behavior near the locus of vapor-liquid critical points to regular thermodynamic behavior outside the critical region. The equation of state yields a satisfactory representation of the thermodynamic-property data for the mixtures in a large range of temperatures and densities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01439196
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Crossover SAFT Equation of State and Thermodynamic Properties of Propan-1-ol (2000)
    Springer
    International journal of thermophysics 21 (2000), S. 1373-1405 
    Details
    ISSN: 1572-9567
    Keywords: associating fluids, critical state ; crossover theory ; equation of state ; enthalpies ; heat capacities ; n-alkanols ; thermodynamic properties ; speed of sound ; vapor–liquid equilibrium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In this work we have developed a new equation of state (EOS) for propan-1-ol on the basis of the crossover modification (CR) of the statistical-associating-fluid-theory (SAFT) EOS recently developed and applied to n-alkanes. The CR SAFT EOS reproduces the nonanalytical scaling laws in the asymptotic critical region and reduces to the analytical-classical SAFT EOS far away from the critical point. Unlike the previous crossover EOS, the new CR SAFT EOS is based on the parametric sine model for the universal crossover function and is able to represent analytically connected van der Waals loops in the metastable fluid region. The CR SAFT EOS contains 10 system-dependent parameters and allows an accurate representation of the thermodynamic properties of propan-1-ol over a wide range thermodynamic states including the asymptotic singular behavior in the nearest vicinity of the critical point. The EOS was tested against experimental isochoric and isobaric specific heats, speed of sound, PVT, and VLE data in and beyond the critical region. In the one-phase region, the CR SAFT equation represents the experimental values of pressure with an average absolute deviation (AAD) of less than 1% in the critical and supercritical regions and the liquid densities with an AAD of about 1%. A corresponding states principle is used for the extension of the new CR SAFT EOS for propan-1-ol to higher n-alkanols.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006657410862
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    A scaled equation of state for real fluids in the critical region (1985)
    Springer
    International journal of thermophysics 6 (1985), S. 465-481 
    Details
    ISSN: 1572-9567
    Keywords: critical phenomena ; equation of state ; scaling laws ; steam ; thermodynamic properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A scaled equation of state is proposed for real fluids in the critical region which incorporates asymmetry with respect to the critical isochore. In the range of reduced densities 0.65⩽(θ/θ c)⩽1.4 and for reduced temperatures (T/T c)⩽1.2, the equation represents P-V-T data for steam within the experimental accuracy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508891
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    An improved parametric crossover model for the thermodynamic properties of fluids in the critical region (1993)
    Springer
    International journal of thermophysics 14 (1993), S. 1-32 
    Details
    ISSN: 1572-9567
    Keywords: critical phenomena ; equation of state ; ethane ; methane ; sound velocity ; specific heat ; thermodynamic properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract An improved parametric equation for the thermodynamic properties of fluids is presented that incorporates the crossover from singular thermodynamic behavior in the immediate vicinity of the critical point to regular thermodynamic behavior far away from the critical point. Based on a comparison with experimental data for ethane and methane, it is demonstrated that the crossover model is capable of representing the thermodynamic properties of fluids in a large range of temperatures and densities around the critical point.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00522658
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Equation of State and Thermodynamic Properties of Pure D2O and D2O + H2O Mixtures in and Beyond the Critical Region (1999)
    Springer
    International journal of thermophysics 20 (1999), S. 563-588 
    Details
    ISSN: 1572-9567
    Keywords: binary mixtures ; critical region ; D2O ; equation of state ; H2O ; phase behavior ; thermodynamic properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A parametric crossover model is adapted to represent the thermodynamic properties of pure D2O in the extended critical region. The crossover equation of state for D2O incorporates scaling laws asymptotically close to the critical point and is transformed into a regular classical expansion far from the critical point. An isomorphic generalization of the law of corresponding states is applied to the prediction of thermodynamic properties and the phase behavior of D2O + H2O mixtures over a wide region around the locus of vapor-liquid critical points. A comparison is made with experimental data for pure D2O and for the D2O + H2O mixture. The equation of state yields a good representation of thermodynamic property data in the range of temperatures 0.8T c(x)≤T≤1.5T c(x) and densities 0.35ρc(x)≤ρ≤1.65ρc(x).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022609205399
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...