• Bulletin of the Korean Chemical Society
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• 제27권4호
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• pp.563-567
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• 2006

The application of a synergistic solvent extraction by the formation of ternary complex with pyrocatechol violet (PV) and benzalkonium chloride (BC) was studied for determination of trace Zn(II) in water samples. The pH of sample solution and the amount of PV and BC added were optimized for the formation of the stable complex, a proper solvent was selected for the effective extraction, and the concentration of nitric acid was fixed for the back extraction of the complex from the solvent. After the ionic strength of 100 mL sample solution was adjusted to 0.1 M by adding NaCl and the pH was fixed at 9 with a carbonate buffer, 1.0 mL of 2% PV solution was added to form Zn(II)-PV complex then the Zn(II)-PV/BC ternary complex was made by adding 1.0 mL of 10% BC solution. The ternary complex was extracted into 10 mL of MIBK. And the ternary complex was back-extracted with 10 mL of 1.0 mol/L nitric acid to determine Zn(II) by a flame atomic absorption spectrophotometer (flame-AAS). The interference of concomitant ions on the extraction of Zn(II) was investigated. This procedure was applied to the analysis of three real samples such as Dalbang-dam water, laboratory tap water and Jungnajin seawater. The recoveries of Zn(II) in spiked samples were 86.58-104.1%.

• Bulletin of the Korean Chemical Society
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• 제24권10호
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• pp.1495-1500
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• 2003

Equilibria and applications of a synergistic extraction were studied for the determination of a trace lithium by using thenoyltrifluoroacetone (TTA) and trioctylphosphine oxide (TOPO) as ligands. Several equations were derived for the extraction of lithium into m-xylene as a phase of Li-TTA·mTOPO adduct. Distribution coefficients and extraction constant were determined together with a stability constant of the adduct. The adduct was quantitatively extracted from the basic solution of higher than pH 9 by shaking for 30 minutes. m-Xylene was selected as an optimum solvent by comparing the extraction efficiency among several kinds of organic solvents. The stability constant (${\Beta}_2$) for Li-TTA/2TOPO was 150 times higher than Li-TTA/TOPO. The distribution coefficient of Li-TTA/2TOPO into m-xylene was 9.12 and the logarithmic extraction constant (log $K_{ex}$) was 6.76. Trace lithium of sub-ppm level in seawater samples could be determined under modified conditions and a detection limit equivalent to 3 times standard deviation for background absorption was 0.42 ng/mL.

• Bulletin of the Korean Chemical Society
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• 제21권9호
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• pp.855-859
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• 2000

An application of synergistic solvent extraction for the etermination of trace lithium in sea water has been studied by forming an adduct complex of thenoyltrifluoroacetone (TTA) and trioctylphosphine oxide (TOPO) in a solvent. The interference by major constituents in sea water was eliminated by phosphate precipitation. Ex-perimental conditions such as solution pH, concentrations of TTA and TOPO etc. were optimized in synthetic sea water with similar compositionto its natural counterpart. To eliminate the interference, 1.38g of ammoni-um dihydrogen phosphate and 2.5 mL of ammonia water were added into 100 mL of thediluted solution at $60^{\circ}C$ to form the phosphate precipitates of Ca2+ and Mg2+ ions. After the pH of this filtrate was adjusted to 8.0, 10.0 mL of m-xylene containing 0.1 M TTA and 0.05 M TOPO was added to the solution in a separatory funnel, and the solution was shaken vigorously for 20 minutes. The solvent was separated from the aqueous solution, and 20 uL of m-xylene solution was injected into a gaphite tube to measure the absorbance by GF-AAS. The detection limit was 0.42 ng/mL. Lithium was determined within the range of 146 to 221 ng/mLin Korean coast-al sea waters, and the recoveries in the spiked samples were 94 to 106%.

• 대한화학회지
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• 제7권4호
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• pp.245-250
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• 1963

TBPO와 TOPO와의 混合溶媒(稀釋制 : toluene)에 依한 三假狀態의 4f 稀土類元素의 抽出에 있어 相乘效果(synerigistic effect)가 나타남을 알았으며 이것은 各 單獨溶媒系에 있어서 生成抽出되는 $M(NO_3)_3\;(TBPO)_3$ 및 $M(NO_3)_3\;(TOPO)_3$型 外에 $M(NO_3)_3\;(TBPO)_2\;(TOPO)$型이 새로히 追加生成됨을 起因된 것으로 認定된다.

• Bulletin of the Korean Chemical Society
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• 제21권1호
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• pp.137-140
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• 2000

• 자원리싸이클링
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• 제26권2호
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• pp.3-10
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• 2017

희토류 원소는 첨단 산업용 소재의 구성 성분으로 고순도가 요구된다. 국내산 monazite광과 Ni-MH전지는 경희토류를 함유한 자원이다. 이러한 자원을 염산으로 침출한 용액에서 경희토류성분을 용매추출로 분리하는 공정에 대해 고찰하였다. 양이온 추출제와 3차 아민의 혼합추출제로 경희토류를 추출시 상승효과가 있으며 pH 감소가 둔화된다. 혼합추출제 사용시 수상의 pH가 금속의 추출 및 상승효과에 미치는 영향을 분석하였다. 향후 양이온과 아민의 혼합추출제에 의한 경희토류 분리공정을 개발하기 위해서는 mixer-settler의 조업 자료 확보가 필요하다.

• 한국응용과학기술학회지
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• 제32권1호
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• pp.31-39
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• 2015

용매추출법에서 희토류 금속을 효과적으로 분리하기 위해 추출제만 사용하는 것이 아니라 crown ether와 같은 첨가제를 이용하는 연구를 하였다. Host-guest 화합물인 macrocyclic ligand는 금속과 착화물을 형성하는데, 이 때 crown ether의 cavity 크기와 비슷한 크기의 금속 이온들과 안정한 착화물을 형성한다. 이전 연구에서 europium과 yttrium을 분리하기 위해 여러 사슬 길이의 지방산 추출제를 이용한 추출실험을 행하였었다. 이를 토대로 분리효율이 좋지 않았던 hexanoic acid에 크기가 다른 crown ether (18-crown-6 ether, 15-crown-5 ether, 12-crown-4 ether)를 첨가하여 분리효과가 증가하는 것을 연구하였다. hexanoic acid의 농도별로 분리효율을 본 후 가장 분리 효율이 좋은 농도에서 crown ether를 종류와 농도를 다르게 하여 첨가하였다. 그 결과 0.05 M hexanoic acid에서 분리능이 1.72으로 가장 높게 나타났고, crown ether를 첨가하였을 시 분리능이 0.002 M 15-crown-5 ether에서 가장 높게 나왔으며 기존의 분리능보다 2배 이상 더 높았다. 또한 crown ether를 첨가하였을 때 두 금속이 $MLR_3{\cdot}3RH$의 형태로 추출되는 것도 확인 할 수 있었다.

• 한국산업융합학회 논문집
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• 제6권3호
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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.

• 분석과학
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• 제8권4호
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• pp.499-503
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• 1995

In order to study how and why the stabilities of lanthanoid(III) complexes in solutions vary across the series, the formation constants of the adducts of tris(2-thenoyltrifluoroacetonato)lanthanoids(III) with seven carboxylic acids in chloroform have been determined by solvent extraction technique at 298K. The formation constants with carboxylic acids generally decrease with increasing the atomic number, but in the middle of the series, they change only slightly. Such trends have been interpreted as related to a change of the coordination number in the middle of the series. It has been attempted to determine the number of water molecules coordinated to the adducts as well as $Eu(TTA)_3$ in chloroform by measuring the fluorescence life time of europium(III), to ensure the assignment of the coordination number.

• 분석과학
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• 제17권1호
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• pp.1-7
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• 2004

N-nitroso-N-phenylhydroxylamineammonium salt(cupferron)과 tetrabutylammonium ion ($TBA^+$)을 사용하여 수용액 중 미량 Mn(II)을 상승 용매 추출하는 법에 대해서 연구하였다. $TBA^+$가 존재할 때 cupferron으로 수용액 중의 Mn(II)을 추출하면 용액의 pH 4-10 범위에서 95% 이상이 추출되지만 $TBA^+$가 존재하지 않으면 거의 추출되지 않았다. 이런 조건에서 Mn(II)의 추출은 $CH_2Cl_2$나 $CHCl_3$와 같은 유기용매를 사용 할 때가 다른 비극성 용매를 사용할 때 보다 현저히 잘 추출되었으므로 여기서는 chloroform을 사용하였다. 그리고 수용액의 pH는 5로 조절하였다. 실제시료 중 존재하는 극미량의 Mn(II)을 정량하기 위해서는 chloroform에 추출된 Mn(II)을 다시 0.1 mol/L $HNO_3$용액에 역 추출하여 GF-AAS로 Mn(II)의 흡광도를 측정하였다. 본 방법으로 얻은 Mn(II)의 검출한계는 0.37 ng/mL이었고, 이 방법을 응용하여 실험실 수돗물 중 Mn(II)을 정량한 결과는 0.4-1.01 ng/mL로 얻어졌다. 이 시료에 일정량의 Mn(II)용액을 첨가하여 얻은 회수율은 94-107%이었다. 그리고 Cu(II), Ca(II), Fe(III) 등 공존하는 다른 원소는 10 내지 $20{\mu}g/mL$까지 Mn(II) 정량에 방해를 하지 않았다. 이로서 본 방법이 극미량 Mn(II)의 새로운 분석법으로 사용될 수 있을 것으로 생각된다.