• Korean Chemical Engineering Research
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• 제53권2호
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• pp.205-210
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• 2015

본 연구에서는 미세조류인 Nannochloropsis sp.로부터 바이오디젤 생산용 지질을 얻기 위하여 유기용매 및 초임계 이산화탄소(SC-$CO_2$)를 이용하여 추출을 수행하였다. SC-$CO_2$ 추출법으로 얻은 지질의 지방산메틸에스테르 함량은 58.31%로 높았으며, Bligh-Dyer 추출법은 18.0 wt.%의 가장 높은 조지방 수율을 나타내었다. SC-$CO_2$ 추출법에 극성을 높이기 위해 공용매로서 methanol을 사용한 결과, 조지방 수율 12.5 wt.%, 지방산메틸에스테르 함량 56.32%, 지방산메틸에스테르 수율 7.04 wt.%였으며, SC-$CO_2$ 만을 이용하는 추출 방법에 비하여 추출 시간을 2시간에서 30분으로 단축시킬 수 있었다. 따라서 미세조류에서 지질을 추출하는데 기존의 유기용매 추출법과 비교하여 SC-$CO_2$ 추출법이 친환경적이며, 효율적인 방법임을 확인하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권4호
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• pp.1-7
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• 2013

Subcritical water which acts as organic solvent with increasing temperature and pressure because dielectric constant and viscosity decrease can be used to remediate PAHs-contaminated soil. Factors influencing on extraction were studied with varying the water temperature $200{\sim}275^{\circ}C$, extraction time 0~90 min, flow rate 10~100 mL/min and pressure 3.9~10MPa. 300 g of soil sample which was contaminated with PAHs(naphthalene, phenanthrene, fluoranthene and pyrene; 423, 420, 539 and 428 mg/kg of initial concentration) was packed into the cell and placed to reactor and then the subcritical water was pumped through the cell for PAHs extraction. Naphthalene was removed almost 100% at relatively low temperature ($200^{\circ}C$). The removal rate of phenanthrene, fluoranthene, and pyrene increased by 8, 26, and 23% when the temperature increased from 200 to $275^{\circ}C$; and it was gradually increased as extraction time increased from 0 to 90 min. Decreasing removal rate when water flow rate increased from 10 to 30 mL/min, but there was no significant change after 30 mL/min. This is supposed due to channeling phenomenon. The pressure was not an effective factor for extraction of PAHs in this study. Based on the results, the importance of effective factor was in following sequence: temperature >> time > flow rate.

• KSBB Journal
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• 제18권5호
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• pp.347-351
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• 2003

초임계 이산화탄소를 이용하여 감초의 glycyrrhizic acid를 추출하기 위하여 일정 유속 (3 mL/min)에서 추출온도와 압력 보조용매의 종류와 첨가량에 대한 효과를 조사하여 보았다. 순수한 초임계 이산화탄소만을 사용해서 감초로부터 glycyrrhizic acid를 거의 추출할 수 없었다. 99.9% methanol, ethanol과 isopropanol을 보조용매로 초임계 이산화탄소에 첨가하여 추출한 경우, 추출수율의 증대에 큰 영향을 미치지 않았으나, 70% (v/v) aqueous methanol, ethanol과 isopropanol을 이산화탄소에 10% (v/v)으로 첨가한 경우에는 급격한 수율의 증대를 볼 수 있었고, 70% (v/v) aqueous methanol을 첨가하였을 때가 96.62 wt%로 가장 높은 회수율을 나타내었다. 한편, 70% (v/v) aqueous ethanol을 보조용매로 사용한 경우의 가장 높은 회수율과 빠른 추출속도를 나타낸 추출압력과 추출온도는 각각 40 MPa과 8$0^{\circ}C$였고, 이 조건하에서 다양한 농도의 aqueous ethanol (50∼90% (v/v))을 보조용매로 사용하였을 때 60% (v/v) aqueous ethanol을 보조용매로 첨가한 경우가 104.11 wt%로 가장 높은 회수율과 빠른 추출속도를 나타내었다. 또한 이산화탄소에 대한 60% (v/v) aqueous ethanol의 첨가량은 15% (v/v)을 첨가하였을 때 60분 내에 최고 회수율 (104.57 wt%)에 도달하였다.

• 공업화학
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• 제7권4호
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• pp.743-749
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• 1996

본 연구에서는 고밀집 섬유 다발체 내에 수용상과 유기상을 동시에 주입시켜 나타나는 모세관 현상을 이용하여 최소 공간에서 최대한의 물질 전달 면적을 갖게 한 정적 액-액 접촉 장치가 개발되었다. 이 장치의 특성과 안정성을 평가하기 위해 TBP와 우라닐 이온을 함유한 질산계의 연속 추출 실험이 수행되었으며, 추출 성능은 동일 상비 조건에서 수행된 회분식 성능과 동일하였다. 초기 수용액에 대한 추출 수율을 증가 시키기 위해서는 일정한 수용액 유속에서 유기상의 유속 증가가 필요하였고, 같은 상비 조건의 회분식의 추출수율을 갖기 위해서는 수용액이 장치 내에서 일정한 체류 시간을 유지해야함을 알 수 있었고 본 추출계에서는 약 1.9분이 필요함을 알 수 있었다. 본 연구에서 개발된 고 밀집 섬유체 접촉기는 안정성과 재현성이 뛰어 났으며, 일반 물질 분리용 뿐만 아니라, 액-액계면 넓고 안정되어 있어 용매 추출 속도론 해석에도 사용될 수 있음을 확인할 수 있었다.

• KSBB Journal
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• 제26권2호
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• pp.165-171
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• 2011

Fractional solvent extraction by organic solvents such as hexane, chloroform, ethylacetate, and butanol was carried out using 70% ethanol extract of apple flower leaves. Biological activities including antioxidant, whitening, antimicrobial and anti-wrinkle activities were investigated and bio-active materials of the extracts were identified using GC/MSD. Among the tested solvent fractions, ethylacetate fraction showed the highest total polyphenol content (1218.94 ${\mu}g/mL$), and flavonoid (140 ${\mu}g/mL$). The DPPH radical scavenging activities was over 80% at a dry matterbased concentration of 200 ${\mu}g/{\mu}L$ and SOD-like activity was over 90% at 50 ${\mu}g/mL$ concentration in ethylacetate fraction that was slightly lower than of ascorbic aicd. Tyrosinase inhibition activity related to skin-whitening was over 60% by ethylacetate fraction of 100 ${\mu}g/mL$. As an anti-aging effect, elastase inhibitory activity was about 45% in ethylacetate fraction. Also, it showed a significantly antimicrobial activity against P. acenes. From GC/MSD analysis, a characteristic peak of high content in ethylacetate fraction was identified as kaempferol, which has been reported as a bioactive compound.

• 한국환경농학회지
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• 제8권1호
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• pp.7-16
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• 1989

토양(土壤), 수(水), 농작물(農作物)중 잔류(殘留)하는 각종(各種) 농약(農藥)의 분석(分析)을 위한 수증기증류법(水蒸氣蒸溜法)의 응용성(應用性) 및 정밀도(精密度)등에 대하여 연구검토(硏究檢討)하였다. 수증기증류(水蒸氣蒸溜)에 의하여 추출(抽出)이 가능(可能)했던 농약(農藥)은 PCNB, ${\alpha}-BHC$, ${\beta}-endosulfan$, IBP, diazinon, fenitrothion, fenthion, alachlor, butachlor, pretilachlor, metolachlor, pendimethalin, benthiocarb, molinate등이었으며 simazine, atrazine, nitrofen등은 불가능(不可能)하였다. 농약(農藥)의 증류(蒸溜)까지 요(要)하는 유출액양(溜出液量)은 농약(農藥)의 종류(種類)에 따라 크게 달랐으며, 일정량(一定量)의 유출액(溜出液)을 취(取)한 후 냉각관(冷却管)을 acetone으로 씻어 줌으로써 증류시간(蒸溜時間)을 단축(短縮)시킬 수 있었다. 수증기증류법(水蒸氣蒸溜法)은 소량(小量)의 유기용매(有機溶媒)로 농약(農藥)의 추출(抽出)이 가능(可能)했으며, 분석대상물질(分析對象物質)에 따라서는 기기분석시(機器分析時) 방해물질(妨害物質)이 검정(檢定)되기는 했지만 많은 경우 농축(濃縮)과 정제과정(精製過程)을 생략(省略)할 수도 있어 매우 유용(有用)한 방법(方法)이라 하겠다.

• Journal of Pharmaceutical Investigation
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• 제16권4호
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• pp.139-147
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• 1986

A singly charged methyl orange(MO) anion was found to be extracted with chlorpheniramine maleate(CPM) as a 1 : 1 complex in chloroform. Of various solvents, MO-chloroform system gave a yellow color for CPM, while in the absence of CPM, an organic phase showed almost no color. In this way, the spectrophotometric method was investigated for the determination of CPM by solvent extraction. The addition of alcoholic bolic acid solution to the solvent extract gave a higher color stability and transparency at least 5 days, but the extract alone lost its color intensity significantly. CPM is determined by measuring the absorbance of the extracts over a range of $1{\sim}7{\times}10^{-4}M\;(39{\sim}273\;{\mu}g/ml)$ in aqueous solution at 423 nm. The molar absorptivity was $2.26{\times}10^3\;l,\;mol^{-1},\;cm^{-1}$. The absorbance of the extract was constant in the range of pH $3.7{\sim}4.6$. This novel method was applied for the determination of CPM in artificial and commercial preparations in comparison with the analytical method of CPM tablets in K.P.IV. The results obtained showed that the former was better in accuracy and time consumption than the latter.

• Membrane and Water Treatment
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• 제8권1호
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• pp.19-34
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• 2017

Boron exists in dilute concentrations in sea water, ground water and waste waters. Reactive liquid extraction can be used for removing boron to make the treated water suitable for drinking and irrigation, with its final concentration less than 0.5 ppm. The results of equilibrium experiments are reported on the removal of boron using 2-butyl-2-ethyl-1, 3-propanediol (BEPD as a nonionic carrier) in sunflower oil, a non-traditional solvent. The results of removal of boron from aqueous solutions in the concentration range 0.5-20 ppm are presented. It is shown that this new liquid membrane system, is able to remove boron from ground waters at their natural pH of 6-8 (without any chemical addition for pH adjustments). The removal efficiency is good when the process is upgraded to a hollow-fibre membrane contactor and approximately 45% boron can be removed in a single-stage contact. There are additional advantages of this new approach that includes reduced operational health and safety and environmental issues. The results reported here provide guidelines to the development of boron removal process using renewable, biodegradable, safe and cheap solvent system such as sunflower oil.

• Journal of Pharmaceutical Investigation
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• 제36권4호
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• pp.245-251
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• 2006

The novel microsphere blending and multiple emulsion method by single process was tried to prepare sustained release microspheres which release a physiologically active substance for long periods of time. A drug was separately dissolved in each of two or more oils containing biodegradable polymers to give the primary oil phases. The primary oil phases were dispersed in single aqueous phase in succession. From the drug-dispersed solution, the organic solvent was removed to produce microspheres. The accelerated drug release from the microsphere formulation prepared by single process through the multiple emulsion method was very similar to a physical blending of separately prepared microspheres using the same polymers. But long term release was not same. In this study, leuprorelin acetate loaded poly(lactide-co-glycolide) microsphere formulation for one-month delivery was developed by the multi-emulsion method followed by solvent extraction/evaporation method.

• Korean Membrane Journal
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• 제1권1호
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• pp.81-85
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• 1999

Tributyl phyosphate(TBP) polypropylene glycol 4000(PPG-4000) and the mixture of two compounds were examined as a liquid membrane in a supported liquid membrane (SLM) to separate phenol from aqueous solution.The feed concentration of phenol was varied in a broad range from 500 mg/L to 5000 mg/L and different types of liquid membrane were prepared to elucidate their effects on separation of phenol. It was found that the modified PPG 4000 with TBP and toluene diisocyanate(TDI) might be used as a proper liquid membrane because the mass transfer rate examined with this membrane was higher than that through methyl isobutyl ketone (MIBK) which has been used as a conventional solvent in a solvent extraction process. The breakthrough pressure of the SLM is defined to be the pressure difference across the membrane at which the supported liquid membrane is not kept in the pores any more. it indicates how the SLM is stable., It was found that the breakthrough pressure of the modified PPG-4000 was much higher than those of typical organic solvents.