Europium and cerium extraction by the nitrobenzene solution of dicarbolide in the presence of polyethylene glycols

1986 ◽  
Vol 51 (3) ◽  
pp. 498-515 ◽  
Author(s):  
Emanuel Makrlík ◽  
Petr Vaňura
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Equilibrium Constants ◽  
Polyethylene Glycols ◽  
Individual Species ◽  
Nitrobenzene Solution ◽  
Separation Factors ◽  
Equilibrium Data

Extraction of Eu3+ and Ce3+ microamounts from 0.1-0.4M perchloric acid by the nitrobenzene solution of dicarbolide H+[Co(C2B9H11)2]- in the presence of polyethylene glycols (Mr = 200, 300, 400) has been studied. The equilibrium data and the typical maxima on the dependence of the metal distribution ratio on the total analytical concentration of polyethylene glycol in the system can be explained assuming that the species ML3+org, ML3+2org, ML3+3org, MLH2+-1org, and HL+org (where M3+ = Eu3+, Ce3+; L = polyethylene glycol) are extracted into the organic phase. The values of extraction and equilibrium constants in the organic phase were determined and the effect of the polyethylene glycol molecular weight on the equilibrium constants and on the abundances of individual species in the organic phase is discussed. It has been found that the addition of polyethylene glycol to the acid - nitrobezene - dicarbolide system increases the values of the separation factors αCe/Eu.

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.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

scholarly journals Distribution of micro-amounts of europium in the two-phase water-HCl-nitrobenzene-N,N'-dimethyl-N,N'-diphenyl-2,6-dipicolinamide-hydrogen dicarbollylcobaltate extraction system

2009 ◽  
Vol 74 (7) ◽  
pp. 781-787 ◽  
Author(s):  
Emanuel Makrlík ◽  
Petr Vaňura ◽  
Pavel Selucký ◽  
Vasily Babain ◽  
Ivan Smirnov
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Extraction And Stability Constants ◽  
Extraction System ◽  
Hydrogen Dicarbollylcobaltate ◽  
Nitrobenzene Solution ◽  
Two Phase ◽  
Equilibrium Data ◽  
Phase Water

Extraction of micro-amounts of europium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of N,N'-dimethyl- -N,N'-diphenyl-2,6-dipicolinamide (MePhDPA, L) was investigated. The equilibrium data were explained assuming that the species HL+, + HL2 , 3+ EuL2 and 3+ EuL3 are extracted into the organic phase. The values of the extraction and stability constants of the species in nitrobenzene saturated with water were determined.

Extraction of europium from acidic aqueous solutions into nitrobenzene by dicarbolide in the presence of polyethylene glycol

1984 ◽  
Vol 49 (6) ◽  
pp. 1367-1381 ◽  
Author(s):  
Petr Vaňura ◽  
Marie Benešová ◽  
Emanuel Makrlík ◽  
Miroslav Kyrš ◽  
Jiří Rais
Keyword(s):  
Polyethylene Glycol ◽  
Aqueous Solutions ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Distribution Ratio ◽  
Europium Complexes ◽  
Peg 400 ◽  
Extraction Constants ◽  
Positively Charged ◽  
The Eu

Extraction of microamounts of 152, 154 Eu from the aqueous solutions of perchloric acid (c(HClO4) = 0.1-0.5 mol l-1) was studied in the presence of 3 . 10-4 -0.3 mol l-1 of polyethylene glycol PEG 400 (L) by the nitrobenzene solutions of Co(III)-dicarbolide (3.3'-commo-bis(undecahydro-1,2-dicarba-3-cobalta-closo-dodecarborate) (-1), {(π-(3)-1,2-B9C2H11)2Co}-, henceforth only B-) of the concentration c(dicarbolide) = 10-3-10-1 mol l-1. Maxima of the Eu distribution ratio dependence on the concentration of polyethylene glycol are explained by the competition reactions between the positively charged europium complexes (EuL3+, EuLH-12+, and EuL23+, EuL2H-22+, or EuL33+) and protonized polyethylene glycol (HL+) in the organic phase. The respective equilibrium extraction constants were determined.

Extraction of strontium with dicarbolide in the presence of polyethylene glycol

1979 ◽  
Vol 44 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Petr Vaňura ◽  
Jiří Rais ◽  
Pavel Selucký ◽  
Miroslav Kyrš
Keyword(s):  
Experimental Data ◽  
Polyethylene Glycol ◽  
Ionic Strength ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Distribution Ratio ◽  
Equilibrium Constants ◽  
Electrostatic Charge ◽  
Peg 400 ◽  
Order Of Magnitude

The extraction of microquantities of 85Sr in the presence of 3 . 10-4 - 0.25 mol l-1 polyethylene glycol (PEG 400) (L) with solutions of dicarbolide ({(π-(3)-1,2-B9C2H11)2Co}-) in nitrobenzene (10-3 - 10-2M) was investigated. The occurrence of the maxima (up to one order of magnitude) on the plots of the strontium distribution ratio vs the total PEG concentration was explained in terms of the competition between the charged strontium-PEG complex (SrL2+) and protonized PEG (HL+) during the balancing of the dicarbolide electrostatic charge in the organic phase. Theoretical relations were derived for the shape of this dependence, for the effect of the acid concentration in the aqueous phase and that of the dicarbolide concentration in the organic phase, as well as for the positions of the corresponding maxima. The theoretical dependences are in accordance with the experimental data. The values of the concentration equilibrium constants of the reactions Sr2+ + L + 2 H+ ##e SrL2+ + 2 H+ (Kex(SrL2+)) and H+ + L ##e HL+ (Kex(HL+)) (for variable ionic strength) are Kex(SrL2+) = 3.26 . 108 and Kex(HL+) = 538 at 25 °C.

scholarly journals Optimization of human somatic cells cryopreservation protocols by polyethylene glycols

2016 ◽  
Author(s):  
O. M. Perepelytsina ◽  
A. P. Ugnivenko ◽  
D. P. Burlaka ◽  
S. V. Bezugly ◽  
M. V. Sydorenko
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Cell Survival ◽  
Somatic Cells ◽  
Polyethylene Glycols ◽  
Low Molecular Weight ◽  
Cooling Speed ◽  
Vitrification Solution

Using of polyethylene glycol in optimization of human somatic cells of cryopreservation protocols was analyzed. Low molecular weight PEG as vitrification solution supplement exhibited a high cooling speed and provided cell survival in 200 % comparing with control. It allows recommending the use of low molecular weight PEG in vitrification environment for effective cell vitrification protocols.

Extraction of Cesium with Bis[undecahydro-7,8-dicarbaundecaborato(2-)]cobaltate(1-) in the Presence of 18-Crown-6

1998 ◽  
Vol 63 (12) ◽  
pp. 2001-2008 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Extraction And Stability Constants ◽  
Nitrobenzene Solution ◽  
Equilibrium Data

Extraction of cesium with a nitrobenzene solution of bis[undecahydro-7,8-dicarbaundecaborato(2-)]cobaltate(1-) in the presence of 18-crown-6 (18C6, L) has been investigated. The equilibrium data and typical dependences of the Cs distribution ratios on the analytical concentration of 18C6 in the system under study can be explained assuming that the complexes HL+, CsL+ and CsL2+ are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

scholarly journals THE STIMULATING EFFECT OF GLYCOLS AND THEIR POLYMERS ON THE TARSAL RECEPTORS OF BLOWFLIES

1948 ◽  
Vol 32 (2) ◽  
pp. 139-151 ◽  
Author(s):  
V. G. Dethier ◽  
L. E. Chadwick
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Chain Length ◽  
Hydrocarbon Chain ◽  
Phormia Regina ◽  
Hydroxyl Group ◽  
Test Material ◽  
Polyethylene Glycols ◽  
Straight Chain ◽  
Molecular Weights

The rejection thresholds of Phormia regina Meigen for twenty-four glycols have been determined. A definite relationship between the concentration of the test material and the distribution of thresholds has been noted regularly in samples of flies selected at random from a population of known age which had been reared under standard conditions. The scattering of thresholds is normal with respect to the logarithm of concentration. Recalculation of the data of other workers reveals the same sort of relationship with other species of insects and the minnow Phoxinus. The underlying reason for the phenomenon is not known. The glycols in common with other series of homologous alipbatic compounds are rejected at logarithmically decreasing concentrations as the chain length is increased. In general the straight chain diols are more stimulating than the corresponding polyethylene and polypropylene glycols. This difference is related in some manner to the presence of ether linkages in the latter. Polypropylene glycols, with chains of three carbon atoms between the ether linkages are more stimulating than polyethylene glycols, where the spacing is —O—C—C—O—. Unipolymers are more stimulating than mixtures of homologues with the same average molecular weights. Polyethylene glycol 1540 is the largest molecule of measured molecular weight known to stimulate chemoreceptors. The introduction of a second terminal hydroxyl group into the straight hydrocarbon chain reduces the stimulating effect. Alcohols corresponding to the first three diols average about four times as stimulating as the latter while those corresponding to the higher diols average more than one hundred times as stimulating.

Extraction of hafnium(IV) with organophosphorus reagents from solutions of mineral acids mixtures

1979 ◽  
Vol 44 (12) ◽  
pp. 3656-3664
Author(s):  
Oldřich Navrátil ◽  
Jiří Smola ◽  
Rostislav Kolouch
Keyword(s):  
Ionic Strength ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Synergic Effect ◽  
Salting Out ◽  
Initial Concentration ◽  
Mixed Complexes ◽  
Synergic Extraction ◽  
Mineral Acids

Extraction of hafnium(IV) was studied from solutions of mixtures of perchloric and nitric acids and of perchloric and hydrochloric acids for constant ionic strength, I = 2, 4, 6, or 8, and for cHf 4 . 10-4 mol l-1. The organic phase was constituted by solutions of some acidic or neutral organophosphorus reagents or of 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, or N-benzoyl-N-phenylhydroxylamine in benzene, chloroform, or n-octane. A pronounced synergic extraction of hafnium proceeds only on applying organophosphorus reagents from an aqueous phase whose acidity is not lower than 3M-(HClO4 + HNO3) or 5M-(HClO4 + HCl). The synergic effect was not affected markedly by a variation of the initial concentration of hafnium in the range 1 . 10-8 -4 .10-4 mol l-1, it lowered with increasing initial concentration of the organophosphorus reagent and decreasing concentration of the H+ ions. It is suggested that the hafnium passes into the organic phase in the form of mixed complexes, the salting-out effect of perchloric acid playing an appreciable part.

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