Relationship between the gas chromatographic behaviour and the molecular structure of hydrocarbon samples and various stationary phases Part I. Correlation of retention data and thermodynamic functions with chemical structure

1980 ◽  
Vol 13 (1) ◽  
pp. 29-34 ◽  
Author(s):  
V. M. Nabivach ◽  
A. V. Kirilenko
Keyword(s):  
Molecular Structure ◽  
Thermodynamic Functions ◽  
Chemical Structure ◽  
Stationary Phases ◽  
Retention Data ◽  
Chromatographic Behaviour

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.

Aqueous Solubility and Related Thermodynamic Functions of Nonaromatic Hydrocarbons as a Function of Molecular Structure

2004 ◽  
Vol 43 (11) ◽  
pp. 2805-2815 ◽  
Author(s):  
Pavla Dohányosová ◽  
Sabine Sarraute ◽  
Vladimír Dohnal ◽  
Vladimír Majer ◽  
Margarida Costa Gomes
Keyword(s):  
Molecular Structure ◽  
Thermodynamic Functions ◽  
Aqueous Solubility

scholarly journals Demystifying and Unravelling the Factual Molecular Structure of the Biopolymer Sporopollenin

2019 ◽  
Author(s):  
Abanoub Mikhael ◽  
Kristina Jurcic ◽  
Celine Schneider ◽  
David carr ◽  
Gregory L. Fisher ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Nuclear Magnetic Resonance ◽  
Chemical Structure ◽  
Pollen Grains ◽  
Outer Wall ◽  
Mass Spectrometric ◽  
Chemical Degradation ◽  
Ionization Mass ◽  
Soft Ionization ◽  
Biochemical Pathways

<p></p><p>Sporopollenin is a natural, highly cross-linked biopolymer composed of carbon, hydrogen, and oxygen, which forms the outer wall of pollen grains. Sporopollenin is resilient to chemical degradation.<sup> </sup>Because of this stability, its exact chemical structure and the biochemical pathways involved in its biosynthesis remains a mystery and unresolved.<sup> </sup></p> <p>We have identified and characterized the molecular structure of the clean, intact sporopollenin using soft ionization mass spectrometric and nuclear magnetic resonance techniques. These analyses showed that sporopollenin contained a poly(hydroxyacid) dendrimer-like network, which accounted for the sporopollenin empirical formula. In addition, the identified hydroxy acid monomers contained a beta diketone moiety, which most probably accounts for the known antioxidant activity of sporopollenin. Moreover, our elucidation studies allowed us to identify a unique circular polyhydroxylated tetraketide polymer. This polymer acted as the rigid backbone on which the poly(hydroxyacid) network can be built, forming the scaffold of the spherical sporopollenin exine.</p><br><p></p>

Chromatographic behaviour and chemical structure of aromatic aldoximes

1973 ◽  
Vol 76 (1) ◽  
pp. 185-189 ◽  
Author(s):  
S. Nes̆ić ◽  
Z. Nikić ◽  
I. Pejković-Tadić ◽  
M. Hranisavljević-Jakovljević
Keyword(s):  
Chemical Structure ◽  
Chromatographic Behaviour

The effect of molecular structure on the anticancer drug release rate from prodrug nanoparticles

2015 ◽  
Vol 51 (64) ◽  
pp. 12835-12838 ◽  
Author(s):  
Yoshikazu Ikuta ◽  
Yoshitaka Koseki ◽  
Tsunenobu Onodera ◽  
Hidetoshi Oikawa ◽  
Hitoshi Kasai
Keyword(s):  
Molecular Structure ◽  
Controlled Release ◽  
Drug Release ◽  
Anticancer Drug ◽  
Release Rate ◽  
Chemical Structure ◽  
Anticancer Agent ◽  
Drug Release Rate ◽  
Drug Nanoparticles

The controlled release of an anticancer agent from drug nanoparticles could be successfully achieved by optimizing the chemical structure of dimeric compounds as prodrug.

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