Optimization of ion-pair extraction by direct measurement of conditional extraction constants with a membrane phase separator

1982 ◽  
Vol 54 (4) ◽  
pp. 697-702 ◽  
Author(s):  
Frederick F. Cantwell ◽  
Carmichael. Murray
Keyword(s):  
Direct Measurement ◽  
Ion Pair ◽  
Membrane Phase ◽  
Extraction Constants ◽  
Phase Separator

Measurement of self-association and ion-pair dissociation constants by solvent extraction using a membrane phase separator

1982 ◽  
Vol 60 (11) ◽  
pp. 1286-1290 ◽  
Author(s):  
Murray Carmichael ◽  
Frederick F. Cantwell
Keyword(s):  
Solvent Extraction ◽  
Methylene Chloride ◽  
Dissociation Constants ◽  
Extraction Constant ◽  
Ion Pair ◽  
Membrane Phase ◽  
Dimerization Constant ◽  
Self Association ◽  
Phase Separator ◽  
Extraction Isotherms

The "filter-probe" membrane phase separator is used with a gravimetric buret to obtain the following constants at 25 °C by measuring solvent-extraction isotherms: dimerization constant of benzoic acid in chloroform (log K2,HBz = 2.12 ± 0.01); "self-ion-pair extraction" constant of Naloxone into chloroform [Formula: see text]; and ion-pair dissociation constant of tetraethylammonium picrate in methylene chloride (log Kdiss = −4.52 ± 0.09).

The extraction of alkali metal picrates by polyurethane foam using crown ether

1981 ◽  
Vol 59 (10) ◽  
pp. 1490-1496 ◽  
Author(s):  
Anjum S. Khan ◽  
W. G. Baldwin ◽  
A. Chow
Keyword(s):  
Crown Ether ◽  
Alkali Metal ◽  
Polyurethane Foam ◽  
Dissociation Constants ◽  
Extraction Constant ◽  
Ion Pair ◽  
Constant Sequence ◽  
Extraction Constants ◽  
The Stability ◽  
Ether Complex

The distribution of alkali metal picrates between water and polyurethane foam was studied in the presence of dicyclohexyl 18-crown-6 (DCHC-6). The extraction constants and dissociation constants for the ion pair (MCrA) in polyurethane foam were determined. The extraction constant sequence of the alkali metal ions with DCHC-6 is K+ > Rb+ > Cs+ > Na+ and mainly depends on the stability of the alkali metal – crown ether complex.

Use of peak height for quantification in solvent extraction/flow injection analysis

1985 ◽  
Vol 63 (9) ◽  
pp. 2559-2563 ◽  
Author(s):  
Jamal A. Sweileh ◽  
Frederick F. Cantwell
Keyword(s):  
Solvent Extraction ◽  
Flow Rate ◽  
Flow Injection Analysis ◽  
Peak Height ◽  
Membrane Phase ◽  
Flow Rates ◽  
Organic Extract ◽  
Sample Concentration ◽  
Band Dispersion ◽  
Phase Separator

The following equation is derived which expresses peak height (P.H.) in terms of sample concentration injected (CSAMP), detector sensitivity (SF), dilution due to band dispersion (Rv), fraction extracted [Formula: see text], flow rates of carrier (FCarrier), organic phase (Fo), and compensating solvent (Fc), and flow rate of organic extract through the membrane phase separator (FM):[Formula: see text]Each term in the equation is evaluated experimentally to validate the equation.

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.

scholarly journals Extraction of Sodium Picrate by 3m-Crown-mEthers and Their Monobenzo Derivatives (m= 5, 6) into Benzene: Estimation of Their Equilibrium-Potential Differences at the Less-Polar Diluent/Water Interface by an Extraction Method

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yoshihiro Kudo ◽  
Tsubasa Nakamori ◽  
Chiya Numako
Keyword(s):  
Extraction Method ◽  
Ion Pair ◽  
Equilibrium Potential ◽  
Straight Line ◽  
Extraction Constants ◽  
Distribution Constants ◽  
The Individual ◽  
Polar Diluent ◽  
O Phase ◽  
Complex Ion

Individual distribution constants (KD,A) of picrate ion (Pic−) and extraction constants (Kex±) of NaPic by some crown ethers (L) into benzene (Bz) at 25°C were calculated from data reported previously. These constants were defined asKD,Pic=Pic-o/[Pic-]andKex±=NaL+oPic-o/(Na+Lo[Pic-]), respectively. Here, the subscript “o” denotes an organic (o) phase and practically o = Bz. 15-Crown-5 ether (15C5), 18-crown-6 one (18C6), and their monobenzo (B) derivatives (B15C5 and B18C6) were selected as L. Interfacial equilibrium-potential differences (Δϕeq) at extraction were estimated at 298 K. A plot oflog⁡Kex±versus-Δϕeqfor the four L extraction systems gave a straight line with slope = 84 V−1. This slope was compared with those, reported before, of the dichloromethane (DCM), 1,2-dichloroethane (DCE), and nitrobenzene (NB) extraction systems. The slopes of the regression lines were in the order NB < DCM ≤ DCE < Bz. Also, the individual distribution constants of the complex ionNaL+and an ion-pair complex (NaL+Pic-) into Bz phase were calculated from the above extraction data. At least, a comparison between these values suggests that Bz molecules mainly interact withNaL+moiety ofNaL+Pic-.

scholarly journals Assignment of individual ion-pair extraction constants based on the Kph4As+=Kph4B-, Kbenzene=1 assumption.

1986 ◽  
pp. 894-900 ◽  
Author(s):  
Issei KASAHARA ◽  
Yorihisa OHGAKI ◽  
Kaoru MATSUI ◽  
Kazuhito KANO ◽  
Shigeru TAGUCHI ◽  
...  
Keyword(s):  
Ion Pair ◽  
Individual Ion ◽  
Extraction Constants
Sign in / Sign up

Export Citation Format

Share Document