• 한국응용과학기술학회지
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• 제22권3호
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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%).

• 한국응용과학기술학회지
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• 제22권1호
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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 $\underline{6}$.

• 한국응용과학기술학회지
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• 제22권1호
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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.

• Applied Biological Chemistry
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• 제40권5호
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• pp.442-446
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• 1997

감도와 재현성이 높은 quinclorac 의 토양중 잔류분석방법 개발을 위해 $CO_2$를 이용한 초임계추출후 4-bromomethyl-7-methoxycoumarin 로 형광유도체화하여 HPLC 상에서 분석하는 방법을 개발하였다. 추출변수로 추출압력과 modifier인 methanol 의 함량을 변화시켜, 100 ppb 처리토양에서 7000 psi $(80^{\circ}C)$, 30% $(methanol/CO_2\;v/v)$) 조건을 이용하여 96% 의 회수율을 얻었다. 18-crown-6-ether 를 촉매로 한 형광유도체 반응은 상온에서 30분이내에 정량적으로 완결되었으며 HPLC-형광분석검출기를 이용하여 토양중 quinclorac의 최소검출 수준을 0.5 ppb까지 낮출 수 있었다. 이 방법은 기존의 방법에 비해 간편하고 감도가 높아 carboxylic acid를 함유한 농약의 잔류분석에 이용될 수 있다고 판단된다.

• 공업화학
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• 제3권2호
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• pp.266-272
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• 1992

아자크라운에테르가 부착된 알킬 페닐포스피닉산을 합성하여 수용액층으로부터 클로로포름층으로 알카리금속이온의 경쟁용매추출 특성을 조사하였다. 연구된 포스피닉산들은 phenylphosphinate, aldehyde 그리고 monoazacrown ether의 한 단계 반응에서 생성되는 포스피네이트 에스테르를 알카리성 가수분해시켜 좋은 수율로 합성할 수 있었다. 합성된 포스피닉산 시약을 착물화제로 사용하여 pH에 따라 수용액층으로부터 클로로포름층으로 알카리 금속이온의 경쟁용매추출 특성을 조사한 결과 이 시약들은 넓은 pH 영역에서 금속이온을 유기용매층으로 추출해냄을 확인하였으며, pH 11인 알카리성 용액에서의 총금속이온부하는 약 75%였다. 이온의 선택성은 아자크라운에테르의 공동크기에 주로 의존하여, monoaza-15-crown-5 기를 갖는 알킬페닐포스피닉산, ${\underline{2}}$, 에서는 $Na^+$ >> $K^+$ > $Rb^+$ > $Li^+$ > $Cs^+$ 순이며 monoaza-18-crown-6 작용기가 있는 알킬페닐포스피닉산, ${\underline{3}}$, 에서는 $K^+$ >> $Rb^+$ > $Na^+$ > $Cs^+$ > $Li^+$ 이온의 순으로 나타났다. 아자크라운에테르포스피닉산들은 유사한 이온선택성을 지닌 크라운에테르카르복실산에 비해 보다 넓은 영역의 pH에서 알카리금속이온의 용매추출이 가능하여, 약한 산성이나 중성 수용액에서도 상당한 정도의 금속이온부하를 나타내었다.