Determination of extraction constants of thallium(I) dithiocarbamates

1983 ◽  
Vol 55 (6) ◽  
pp. 910-913 ◽  
Author(s):  
Govindaraju. Soundararajan ◽  
Masilamani. Subbaiyan
Keyword(s):  
Extraction Constants

Determination of Procaine and Related Local Anesthetics. I. Partition Chromatographic Separation and Assay of Mixtures of Procaine with Tetracaine and with Propoxycaine

1975 ◽  
Vol 58 (1) ◽  
pp. 88-92
Author(s):  
Thomas D Doyle ◽  
Joseph B Proctor
Keyword(s):  
Local Anesthetics ◽  
Chromatographic Separation ◽  
Ion Pair ◽  
Sodium Bromide ◽  
Chromatographic System ◽  
Extraction Constants ◽  
Bromide Ion ◽  
Selection Of

Abstract Determination of ionization and extraction constants for procaine, tetracaine, and propoxycaine led to selection of a simple partition chromatographic system for separation and assay of mixtures of these anesthetics. A 65% solution of chloroform in isooctane elutes tetracaine or propoxycaine from a pH 4:sodium bromide column; procaine is retained and subsequently eluted by chloroform as the bromide ion-pair. The anesthetics are then determined spectrophotometrically. Results of assay of standard and commercial formulations are presented.

Extraction of Selected Organic Bases from Water into Chloroform by Means of the Cobaltacarborane Anion

1998 ◽  
Vol 63 (7) ◽  
pp. 967-976 ◽  
Author(s):  
Oldřich Navrátil ◽  
Zdeněk Skaličan ◽  
Zbyněk Kobliha ◽  
Emil Halámek
Keyword(s):  
Solvent Extraction ◽  
Aqueous Phase ◽  
Organic Nitrogen ◽  
Base Cations ◽  
Photometric Determination ◽  
Nitrogen Base ◽  
Organic Bases ◽  
Quaternary Salts ◽  
Extraction Constants

The cobaltacarborane anion labelled with 60Co was used to study the solvent extraction and stability of its ion associates with a series of organic nitrogen base cations or quaternary salts, some of which are psychoactive. The aqueous phase was 0.1 M HCl, the organic phase was chloroform. The extraction constants of the ion associates were calculated. A method was devised for competitive extraction of ion associates with additional dye anions which are used in the extraction-photometric determination of selected bases.

Extraction and Partition Chromatography of Tolbutamide as Ion-Pairs with Quaternary Ammonium Cations

1976 ◽  
Vol 59 (5) ◽  
pp. 1170-1174
Author(s):  
Thomas D Doyle ◽  
Susan Barkan
Keyword(s):  
Free Acid ◽  
Ion Pairs ◽  
Ammonium Hydroxide ◽  
Ammonium Ion ◽  
Quantitative Calculation ◽  
Treatment Standard ◽  
Extraction Constants ◽  
Immobile Phase ◽  
Chromatographic Procedure

Abstract The partition of tolbutamide (1-butyl-3-(p-tolylsulfonyl) urea) as ion-pairs with homologous tetraalkyl ammonium cations was studied. The determination of experimental extraction constants permitted quantitative calculation of distribution ratios, in agreement with theoretical relationships, over a continuous range of about one billion. The nature and the concentration of the counter-ion and solvent composition were the variables studied. Based on the theoretical results, a rapid partition chromatographic procedure was devised. A solution of tolbutamide sample in 10% aqueous tetraethyl ammonium hydroxide is incorporated in the system as the immobile phase in the partition column. A 1 + 1 mixture of chloroform and isooctane removes extraneous materials; then chloroform elutes the tolbutamide-tetraethyl ammonium ion-pair, which is converted to the free acid by passing the eluate through a phosphoric acid segment, and tolbutamide is determined spectrophotometrically without further treatment. Standard recoveries averaged 100.5 ± 0.70%; commercial tablets assayed 100.5 ± 0.85%.

Determination of extraction constants of metal diethyldithiocarbamates

1968 ◽  
Vol 40 ◽  
pp. 93-100 ◽  
Author(s):  
Jiřf Starý ◽  
Karel Kratzer
Keyword(s):  
Extraction Constants

Determination of extraction constants of tellurium pyrasolindithiocarbaminates

1974 ◽  
Vol 270 (3) ◽  
pp. 205-206
Author(s):  
A. I. Busev ◽  
V. M. Byrko ◽  
N. L. Dobychina ◽  
M. B. Polinskaja
Keyword(s):  
Extraction Constants

Extraction of strontium and barium by nitrobenzene solution of dicarbolide in the presence of polyethylene glycols

1982 ◽  
Vol 47 (5) ◽  
pp. 1444-1464 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík ◽  
Jiří Rais ◽  
Miroslav Kyrš
Keyword(s):  
Polyethylene Glycol ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Polyethylene Glycols ◽  
Hydration Numbers ◽  
Nitrobenzene Solution ◽  
Karl Fischer Titration ◽  
Peg 400 ◽  
Extraction Constants

Extraction of microamounts of Sr2+ and Ba2+ from 0.2-1.0M-HClO4 by the nitrobenzene solutions of dicarbolide H+[Co(C2B9H11)2]- in the presence of polyethylene glycols (PEG) (Mr = 200, 300, 400) has been investigated. It has been found that the extraction of the protonized polyethylene glycol molecule (H+ + L ##e HL+, where the bar denotes species present in the organic phase) and the extraction of the complex between the extracted ion and polyethylene glycol, i.e., M2+ +L + 2 H+ ##e ML2+ + 2 H+, are the predominant reactions in this system. The respective equilibrium constants have been determined. The hydration numbers of HL+ and ML2+ ions in the organic phase have been obtained from the determination of water content by Karl Fischer titration method. The extraction constants and stability constants in the organic phase increase in the sequence H+ < Sr2+ < Ba2+ and PEG 200 < PEG 300 < PEG 400, while the hydration numbers decrease in the same sequence. Correlations between the hydration numbers and the extraction constants for these cations have been found.

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