• Analytical Science and Technology
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• v.10 no.1
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• pp.60-65
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• 1997

Solvent extraction of alkali metal and alkaline earth metal cations by mono-crown ether(benzo-15-crown-5) and bis-(crown ether)s(ethylenediamine bis(4'-formyl benzo-15-crown-5)) containing benzo-15-crown-5 moieties were investigated with water-chloroform system at $25^{\circ}C$. The order of the extraction equilibrium constants($K_e$) and the complexation constants($K_c$) for the alkali metal and alkaline earth metal cations with mono-crown ether and bis-(crown ether)s were Ca(II)>Na(I)>Sr(II)>K(I)>Mg(II)>Rb(I) and Sr(II)>Ca(II)>K(I)>Rb(I)>Mg(II)>Na(I) respectively. These results were explained in terms of the size effect of metal cation and electron density effect. Also, the bis-(crown ether)s was found to extract metal cations more effectively than the corresponding mono-crown ether.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.31-39
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• 2015

The synergistic solvent extraction of rare earth elements such as europium and yttrium has been investigated by the extractant with crown ether as an additive. Macrocyclic ligand as host-guest compounds form more stable complexes with metal ions which have the similar size of the cavity of crown ether. In our previous study[14] founded that the extraction used fatty acid of the various alkyl chain length. Based on the results of the previous experiment, the synergistic separation effect of two metals investigated that the hexanoic acid had was the worst extraction effect which added a crown ether such as 18-crown-6 ether, 15-crown-5 ether, and 12-crown-4 ether. In this study, the concentrations of hexanoic acid have showed the separation effect, and then the concentrations and kind of crown ether are performed for synergistic extraction at the hexanoic acid concentration of the highest separation effect. As a results, the separation rate is the highest value of 1.72 at 0.05 M hexanoic acid, and 0.002M 15-crown-5 ether is the best value in other concentrations and kind of crown ether, it is about twice of using only hexanoic acid. Moreover, the extraction species of two metals has been founded $MLR_3{\cdot}3RH$ form when added the crown ether.

• Journal of the Korean Chemical Society
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• v.30 no.4
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• pp.359-368
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• 1986

Solvent extraction equilibria of alkali metal cation with crown ether (DC18C6, DC24C8) and HDEHP have been studied. The extraction equilibrium constants increase in the order of, in the DC18C6 system, $Na^+, and in the DC24C8 system, $Rb^+. The species extracted to organic phase are $M_1(crown ether)_1\;(HDEHP)_1$. The magnitude of extraction equilibrium constant is determined by the distribution ratio of crown ether between organic and aqueous phase, and stability constant of crown ether-alkali metal complex.

• Journal of the Korean Applied Science and Technology
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• v.22 no.3
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• pp.219-227
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• 2005

Competitive solvent extraction of the mixure of alkali metal and alkaline earth cation from water into organic solvent containing the crown ether carboxylic acid and anlogous crown ether phosphonic acid was investigated as follows. The lipophilic group is found to strongly influence to the selective extraction in the mixed systems from only alkali metal cation for sym-(n-decyldibenzo)-16-crown-5-oxyacetic acid $\underline{1}$ to mostly alkaline earth metal cation for sym-bis[4(5)-tert-butylbenzo]-16-crown-5-oxyacetic acid $\underline{3}$. Monoethyl sym-(n-decyldibenzo)-16-crown-5-oxymethylphosphonic acid $\underline{2}$. and monoethyl-sym- bis]4(5)-tert-butylbenzo]-16-crown-5-oxymethylphosphonic acid $\underline{4}$ showed good selectivity for $Na^+$ over $Mg^{2+}$, the second extracted ion. Structural variation in the crown ether phosphonic acid somewhat was influenced to the extraction selectivity in the mixed systems. when variation of the ionized group is influenced in the mixed systems, the selectivity of $Na^+$ as the second extracted ion was much better crown ether carboxylic acid $\underline{1}$ than crown ether phosphonic acid $\underline{2}$, while the efficiency of $Na^+$ extraction was better $\underline{2}$ (83% total loading) than $\underline{1}$ (32%).

• Journal of Ginseng Research
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• v.13 no.2
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• pp.198-201
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• 1989

The amounts of panaxynol and panaxydol, which are major polyacetylone compounds In white ginseng were determined by capillary-GC (FID), and the extraction efficiencies when using varictus extraction solvents (petroleum ether, dichloromethane, ether, ethyl acetate, acetone, acetonitrilr and methanol) and various extraction methods (shaking, Soxhlet and reflux) were compared . The GC column was SPB-1 fused silica capillary (0.25 mm id x30 m, Supelco), and the column oven temperature was programmed to rise from $200^{\circ}C$ to $300^{\circ}C$ at the rate of $4^{\circ}C$ per minute. The extraction efficiencies for panaxynol and panaxydol according to extraction souvtints were the highest in methanol and decreased in the order of dichloromethane, acetone, ether, ethyl acetate, acetonitrile and petroleum ether. The extracttion efficiencies for panaxynol and panaxydol according to extraction methods were the highest for reflux and the lowest for shaking, and those with Soxhlet were almost equal to those for reflux. The analytical amounts of panaxynol and panaxydol obtained by reflux with methanol %mere 4.2 and 6.4 mg/g, respectittely in white ginseng.

• Resources Recycling
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• v.9 no.3
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• pp.29-36
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• 2000

A study on the recovery of gallium from leaching solutions is carried out by solvent extraction in order to produce gallium oxide of high purity. The results show that the extraction of gallium is found to be increase with acidities of aqueous solution up to 7.4 M/L when pure isopropyl ether is used. And the extraction of iron also increases with increasing acidity of aqueous solution. It appears that the separation of gallium from iron cannot be satisfactorily accomplished with isopropyl ether. But, in the case of extaction with D2EHPA, almost complete extraction of iron is achieved-leaving all the gallium in the aqueous solution-by maintaining the acidity of aqueous solution at 2 M/L. Accordingly, $Ga_2O_3{\cdot}H_2O$ of more than 99wt.% in purity can be produced from zinc residues through the processes comprising of alkali leaching, precipitation by neutralization and solvent extraction using isopropyl ether and D2EHPA as extractants.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.165-169
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• 2003

To extract alkali metal ions and heavy metal ions, search for crown ether model compounds (4a-b, 5a-b, 6a-b) bearing side arm has led to achieve in 5~6 steps starting from 2,6-dimethylaniline. The determination of structure in their compound derivatives were on the basis of melting point and nuclear magnetic resonance spectroscopy. In the solvent extraction of metal ions from the synthesized derivatives, we observed that silver ion has only high selectivity for synergistic ligation of crown ether.

• Journal of the Korean Applied Science and Technology
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• v.22 no.1
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• pp.50-55
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• 2005

A comparison of alkali metal cation and alkaline earth cation solvent extraction was made for three additional monoionizable crown ethers and one diionizable crown ether. sym-(n-Octyldibenzo)-16-crown-5-oxyacetic acid $\underline{1}$ exhibited high efficiency and selecvity in solvent extraction of alkali metal cations with respect to that observed with alkaline earth cations. Sizes of $Na^+$ and $Ca^{2+}$ appropriately match with the cavity size of monoethyl sym-bis[4(5)-tert-butylbenzo]-16-crown-5-oxymethylphosphonic acid $\underline{3}$. As the result, $Na^+$ and $Ca^{2+}$ are the best extracted. sym-(n-Octyldibenzo)-16-crown-5-oxymethyldiphosphonic acid $\underline{4}$was found to be somewhat selective for $Na^+$ over $Li^+$ and other alkaline earth metal cations. In the complexation of alklaine earth cations by crown ether diphosphonic acid $\underline{4}$, $Ca^{2+}$ and $Sr^{2+}$ are the appropriate sizes, but lager $Ba^{2+}$ may be due to favorable formation of a sandwich type complex between the crown ether cavity and the dianion of the deprotonated crown ether phoaphonic acid moiety.

• Journal of the Korean Applied Science and Technology
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• v.22 no.1
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• pp.9-14
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• 2005

Competitive solvent extraction of alkaline earth metal cations from water into organic solvent containing the carboxylic acid crown ether and analogous crown ether phosphonic acid monoethyl esters were investigated. sym-(n-Decyldibenzo)-16-crown-5xyacetic acid $\underline{1}$ and monoethyl sym-(n-decyldibenzo)-16-crown-5-oxymethylphosphonic acid $\underline{3}$ are structurally identical except for the ionizable groups. Both of them provide similar extraction behavior in terms of efficiency and selectivity, but monoethyl sym-(n-decyldibenzo)-16-crown-5-oxymethylphosphonic acid $\underline{3}$ showed higher alkaline earth metals loadings at acidic or neutral media. Monoethylsym-(n-octyldibenzo)-16-rown-5-oxymethylphosphonic acid $\underline{2}$ showed better selectivity and alkaline earth metals loading than did the analogous sym-(n-octyldibenzo)-16-crown-5-oxymethyldiphosphonic acid $\underline{6}$.

• Food Science and Preservation
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• v.5 no.1
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• pp.81-87
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• 1998

Antimicrobial activities of the extracts from spices microorganisms related to kimchi fermentation were investigated. 32 kinds of spices such as allspice, mount, basil, bay leaves, caraway, cardamon, celery, chilli powder, chives, cinnamon, clover, coriander, cumin, dill, fennel, garlic, horseradish, marjorarm, mugwort, mustard, nutmeg, onion, oregano, paprika, parsely, pepper, peppermint, rosemary, sage, tarragon, thyme and tumeric were extracted with water, ethyl ether, ethyl acetate and ethanol. Fractions were tested for antimicrobial activities against Lactobacillus plantarum and Leuconostoc mesenteroides, The extracts of 28 kinds of spices except caraway, cardamon, paprika and tarragon by water extraction, those of 29 kinds except arrowroot, paprika and tarragon by ethyl ether extraction, those of 30 kinds except paprika and tarragon by ethyl acetate extraction, and those of 29 kinds except clover, paprika and tarragon by ethanol extraction showed strong antimicrobial activities against Lactobacillus plantarum. On the other hand, the extracts of 28 kinds of spices except caraway, cardamon, paprika and thyme by water extraction, those of 27 kinds except cardamon, cumin, paprika, tarragon and thyme by ethyl ether extraction, thou of 30 kinds except paprika and thyme by ethyl acetate extraction, and those of 28 kinds except cardamon, cumin, paprika and thyme by ethanol extraction showed strong antimicrobial activities against Leuconostoc mesenteroides.