The partition separation of tropane alkaloids

1954 ◽  
Vol 7 (2) ◽  
pp. 189 ◽  
Author(s):  
W Botttomley ◽  
PI Mortimer
Keyword(s):  
Distribution Coefficient ◽  
Organic Phase ◽  
Tropane Alkaloids ◽  
Partition Chromatography ◽  
Aqueous Buffer ◽  
Chromatography Column ◽  
True Distribution

Data on the partition of tropane alkaloids between an aqueous buffer phase, of varied pH, and chloroform are presented in terms of the pH at which 50 per cent. extraction occurs. The true distribution coefficient of some of the alkaloids is derived from the data. The effect of varying the organic phase has been studied. From the data obtained, the operation of an analytical partition chromatography column is described.

scholarly journals Log D Analysis Using Dynamic Approach

2018 ◽  
Author(s):  
Ganesh Kumar Paul ◽  
Prashanth Alluvada ◽  
Esayas Alemayehu ◽  
M.S. Shahul Hameed ◽  
Wasihun Alemayehu ◽  
...  
Keyword(s):  
Distribution Coefficient ◽  
Nalidixic Acid ◽  
Organic Phase ◽  
Algebraic Method ◽  
Pharmaceutical Formulations ◽  
Dynamic Approach ◽  
Ionic State ◽  
Lipinski’S Rule ◽  
Aqueous Buffer ◽  
Amphoteric Molecules

ABSTRACTLog D is one of the important parameters used in Lipinski’s rule to assess the druggability of a molecule in pharmaceutical formulations. It represents the logarithm (log10) of the distribution coefficient (D) of a molecule. The distribution coefficient is defined as the ratio of the concentration of the sum of ionized and unionized species of a molecule distributed between a hydrophobic organic phase and an aqueous buffer phase. Since the pH affects the ionic state of a molecule, log D value (which is dependent on the concentrations of the ionized species) also becomes dependent on pH. In this work, the conventional algebraic method is compared with a more generalized ‘dynamic’ approach to model the distribution coefficient of amphoteric, diamino-monoprotic molecule and monoprotic acid in the presence of salt or co-solvent. Recently reported experimental log D data of amphoteric molecules such as nalidixic acid, mebendazole, benazepril and telmisartan, were analyzed using both these approaches to show their equivalence.GRAPHICAL ABSTRACT

scholarly journals Extraction Recovery of Vanadium(V) by Amines

2020 ◽  
Author(s):  
Lyudmila D. Kurbatova ◽  
Olga V. Koryakova ◽  
Marina S. Valova
Keyword(s):  
Infrared Spectroscopy ◽  
Distribution Coefficient ◽  
Organic Phase ◽  
Distribution Coefficients ◽  
Extraction Recovery ◽  
Medium Concentration ◽  
Solvent Type

The extraction of vanadium (V) by N-(2-hydroxy-5-nonylbenzyl)-β, β- dihydroxyethylamine was studied depending on different factors, such as pH of the medium, concentration of extracting agent, temperature and solvent type. This allowed the optimal extraction conditions to be determined. It was shown that extraction of vanadium (V) takes place with high distribution coefficients, and a complex containing a decavanadate anion and four molecules of the extractant is formed in the organic phase. The extracted vanadium (V) complex with amine is stable for more than one month. Keywords: extraction, vanadium, distribution coefficient, infrared spectroscopy

Extraction of Technetium as [Tc(II)(NO)(AHA)2H2O]+ Species in the UREX Process

2009 ◽  
Author(s):  
Patricia Paviet-Hartmann ◽  
Ana Nunez Gomez-Aleixandre ◽  
Joshua Pak ◽  
Amparo Glez Espartero ◽  
Frederic Poineau ◽  
...  
Keyword(s):  
Phase Composition ◽  
Nitric Acid ◽  
Distribution Coefficient ◽  
Recent Work ◽  
Crown Ethers ◽  
Organic Phase ◽  
Dielectric Constants ◽  
Acetohydroxamic Acid ◽  
Ring Size ◽  
Reductive Nitrosylation

As it is envisioned today, the first segment of the UREX+ process uses low nitric acid concentrations for U(VI) extraction where pertechnetate anion, TcO4−, can be co-extracted with the uranyl and nitrate into TBP-hydrocarbon solutions. A reductant complexant, acetohydroxamic acid (AHA) is added to the process through the scrub to limit the extractability of plutonium and neptunium. Recent work performed in our laboratory (Ref. 1) demonstrated that TcO4− undergoes reductive nitrosylation by AHA under a variety of conditions. The resulting divalent technetium is complexed by AHA to form the pseudo-octahedral trans-aquonitrosyl-(diacetohydroxamic)-technetium(II) complex ([Tc(II)(NO)(AHA)2H2O]+). In this paper, we are reporting the extraction of [Tc(II)(NO)(AHA)2H2O]+ complex by new designed macrocompounds as well as commercially available crown ethers from 18-crown-6 to 24-crown-8 in ring size and of varying derivatization. Several organic diluents with different dielectric constants are used to enhance the distribution coefficient of technetium (II). The experimental efforts are focused on determining the best extraction conditions by varying the macrocomponds nature and concentration, and the organic phase composition.

The Iodine Propanenitrile Water-System. Effects of Added Salts on Distribution Coefficient and Conductivity

1987 ◽  
Vol 40 (1) ◽  
pp. 209
Author(s):  
J Avraamides
Keyword(s):  
Distribution Coefficient ◽  
Organic Phase ◽  
Water System ◽  
Solvent System ◽  
Distribution Coefficients ◽  
Metal Halides ◽  
Two Phase ◽  
Water Solvent ◽  
Positive Effect ◽  
Zinc Iodide

Distribution coefficients for iodine in the propanenitrile-water solvent system were measured as a function of the nature and concentration of various added metal halides. BothNaCl and KI at concentrations between 1 and 3 M had a positive effect on the distribution coefficient. Zinc halides, particularly zinc iodide, tended to lower the distribution coefficient significantly and also raised the conductivity of the organic phase. These studies suggest that the two-phase solvent system is suitable for application in a zinc-iodine battery.

Characterization of Proanthocyanidin-Rich Dentin Biomodifiers from Plants by Centrifugal Partition Chromatography

Planta Medica ◽  
2013 ◽  
Vol 79 (10) ◽  
Author(s):  
JW Nam ◽  
RS Phansalkar ◽  
JG Napolitano ◽  
SN Chen ◽  
JB McAlpine ◽  
...  
Keyword(s):  
Partition Chromatography ◽  
Centrifugal Partition Chromatography

One-step preparative isolation of aristolochic acids by strong ion-exchange centrifugal partition chromatography

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
AA Abdelgadir ◽  
L Boudesocque-Delaye ◽  
I Thery-Koné ◽  
A Gueiffier ◽  
EM Ahmed ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Partition Chromatography ◽  
Centrifugal Partition Chromatography ◽  
Preparative Isolation ◽  
Aristolochic Acids ◽  
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