• 한국환경과학회지
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• 제7권6호
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• pp.753-759
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• 1998

In physical and reactive extraction of acrylic acid using various solvents the equilibrium characteristics of extraction were investigated. The degree of extraction in reactive extraction with Tri-n-octylamine(TOA) was 1.5~3 times than that in physical extraction. Distribution ratio was constant in methyl isobutyl ketone(MIBK) and n-butylacetate(n-BAc) but was increased with increasing the concentration of acrylic acid in benzene and chloroform. It can be explained by formation of dimers. Maximum extraction leadings of acrylic acid were three in benzene and were two in MIBK, chloroform and n-BAc, and it was found that acrylic acid was extracted as the form of $A_3$R In benzene and $A_2R$ in MIBK, chloroform and n-BAc. In effect of solvent, the degree of extraction was increased as he difference of solubility parameter of solvent and solute was decreased, and as dielectric constant of solvent was increased.

• 분석과학
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• 제36권3호
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• pp.128-134
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• 2023

병풀(Centella asiatica) 추출물인 asiaticoside와 madecassoside는 항균성 및 피부재생 등의 효과로 인해 아시아 지역에서 치료용 연고에 사용되고 있으며, 병풀의 재배 및 추출효율을 높이기 위한 연구가 상업화를 위해 활발히 진행되고 있다. 본 연구에서는 환경 친화적인 추출 용매인 deep eutectic solvents(DESs)가 병풀에서 asiaticoside와 madecassoside의 추출 효율에 미치는 영향을 관찰하기 위하여 다양한 수소결합 받개(hydrogen bond acceptor, HBA)와 주개(hydrogen bond donor, HBD)의 혼합 몰비(HBA1: HBD2, HBA1:HBD3, HBA1:HBD4, 그리고 HBA1:HBD5)로 제조하여 추출용매로 사용하였며, 용매 추출에서 일반적으로 사용되고 있는 추출용매인 증류수(DW)와 methanol (MeOH)의 추출 결과를 최적화된 HPLC조건으로 분리하여 정량 분석하였다. 그 결과, DW와 DES를 3:7로 혼합하여 사용한 경우가 단일 MeOH를 사용한 경우보다 약 1.4배 높은 추출 효율을 보였다. 반대로 MeOH과 DES를 3:7로 혼합하여 사용하는 경우에서는 단일 MeOH를 사용하는 경우보다 약 6 % 낮은 추출 효율을 보였다.

• 한국산업보건학회지
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• 제16권2호
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• pp.91-100
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• 2006

The purpose of this study was to validate alternative method by using non-carcinogenic, and less toxic solvents than NIOSH analytical method 5524 for measuring the airborne MWFs in workplaces. In laboratory tests, the ETM solvents(mixture of same volume for ethyl ether, toluene, and ethanol) were selected. The alternative method of analyzing MWFs, referred to as the ETM solvent extraction method, showed 0.04 mg/sample as LOD, and 0.15 mg/sample as LOQ. The analytical precision (pooled CV, coefficient of variation) of the ETM solvent extraction method for analyzing the straight, soluble, semisynthetic, and synthetic metalworking fluid was 1.5%, 2.0%, 2.6%, 1.6%, respectively, which was similar to the precision (2.6%) of NIOSH analytical method (NIOSH 0500) for total dust. The analytical accuracy by recovery test, spiked mass calculated as extractable mass, was almost 100%. As the result of storage stability test, metalworking fluid samples should be stored in refrigerated condition, and be analyzed in two weeks after sampling. The 95% confidence limit of the estimated total standard error for the ETM solvent extraction method for analyzing the straight, soluble, semisynthetic, and synthetic metalworking fluid was ${\pm}12.6%$, ${\pm}12.5%$, ${\pm}14.0%$, and ${\pm}13.6%$, respectively, which satisfied the OSHA sampling and analytical criteria.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3241-3247
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• 2012

Ionic liquids (ILs) have been extensively investigated as promising alternatives to conventional organic solvents such as sulfolane and N,N-dimethylformamide for the selective extraction of aromatic hydrocarbons from the $C_6-C_{10}$ hydrocarbon mixtures produced from the cracking processes of naphtha and light oils. The most important advantage of ILs over conventional organic solvents is that they are immiscible with aliphatic hydrocarbons, and thus the back extraction of ILs from the raffinate phases and top hydrocarbon-rich layers is not necessary. In this paper, a brief review on the state of the art in the utilization of ILs for aromatics separation is presented.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.695-702
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• 2015

Liquid-liquid extraction (LLE) using various solvents was studied for recovery of acetic acid from a synthetic ethanol fermentation broth. The microbial fermentation of sugars presented in hydrolyzate gives rise to acetic acid as a byproduct. In order to obtain pure ethanol for use as a biofuel, fermentation broth should be subjected to acetic acid removal step and the recovered acetic acid can be put to industrial use. Herein, batch LLE experiments were carried out at $25^{\circ}C$ using a synthetic fermentation broth comprising $20.0g\;l^{-1}$ acetic acid and $5.0g\;l^{-1}$ ethanol. Ethyl acetate (EtOAc), tri-n-octylphosphine oxide (TOPO), tri-n-octylamine (TOA), and tri-n-alkylphosphine oxide (TAPO) were utilized as solvents, and the extraction potential of each solvent was evaluated by varying the organic phase-to-aqueous phase ratios as 0.2, 0.5, 1.0, 2.0, and 4.0. The highest acetic acid extraction yield was achieved with TAPO; however, the lowest ethanol-to-acetic acid extraction ratio was obtained using TOPO. In a single-stage batch extraction, 97.0 % and 92.4 % of acetic acid could be extracted using TAPO and TOPO when the ratio of organic-to-aqueous phases is 4:1 respectively. A higher solvent-to-feed ratio resulted in an increase in the ethanol-to-acetic acid ratio, which decreased both acetic acid purity and acetic acid extraction yield.

• Journal of Korean Society for Atmospheric Environment
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• 제14권E호
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• pp.27-40
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• 1998

The solubility characteristics of organic compounds were studied in terms of the extraction efficiency as a function of the polarity of the organic solvent, and the acidity of water in urban aerosol samples collected in University of East Anglia (UEA), Norwich, England. The extraction efficiency of organic compounds were evaluated with respect to the organic carbon, -nitrogen and -hydrogen by means of a wide range of solvent which include polar and nonpolar organic solvents as well as acids and alkaline water. In addition, after being dissolved in aqueous solution, the aqueous chemistry of organic compounds were studied in terms of the organic metal complexes in aerosol, which were studied with oxalic acid, copper, and zinc. The results of this study indicate that solubility characteristics of organic compounds depend on the polarity of the solvents and the acidity of the solvents. In particular, some organic compounds are water soluble, even though they are much smaller than acetone soluble fractions. In the comparison between polar organic solvent extraction and non- polar organic solvent extraction, it can be thought that significant fraction of organic compounds analysed in the aerosol samples, are polar organic compounds because of the higher extraction efficiencies of organic compounds in polar organic solvent extraction than in nonpolar organic solvent extraction. Regarding the study of the oxalic -metal complexes, it can be thought that most oxalic acids are present in the form of oxalic -copper complexes in the aerosols collected at UEA.

• 한국물환경학회지
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• 제36권1호
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• pp.48-54
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• 2020

This paper presents a screening protocol for the selection of solvents available for the solvent extraction desalination process. The desalination solvents hypothetically and theoretically require the capability of (1) Forming hydrogen bonds with water, (2) Absorbing some water molecules into its non-polar solvent layer, (3) Changing solubility for water-solvent separation, and (4) Rejecting salt ions during absorption. Similar to carboxylic acids, amine solvents are solvent chemicals applicable for desalination. The key parameter for selecting the potential solvent was the octanol-water partitioning coefficient (Kow) of which preferable value for desalination was in the range of 1-3. Six of the 30 amine solvents can absorb water and have a variable, i.e., temperature swing solubility with water molecule for water-solvent separation. Also, the hydrogen bonding interaction between solvent and water must be stronger than the ion-dipole interaction between water and salt, which means that the salt ions must be broken from the water and only water molecules absorbed for the desalination. In the final step, three solvents were selected as desalination solvents to remove salt ions and recover water. The water recovery of these three solvents were 15.4 %, 2.8 %, 10.5 %, and salt rejection were 76 %, 98 %, 95 %, respectively. This study suggests a new screening protocol comprising the theoretical and experimental approaches for the selection of solvents for the desalination method which is a new and challenges the desalination process in the future.

• KSBB Journal
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• 제22권3호
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• pp.174-178
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• 2007

본 연구는 고추냉이로부터 항균활성을 가지는 휘발성황 화합물인 AITC를 중점으로 ITCs 류를 $SCO_2$를 이용한 추출 목적으로 하였다. 연구에서 semi-continuous flow 추출장치를 이용해 AITC를 추출한 결과 기존의 에테르나 에탄올 등 유기용매와 비교 시 7.9 AITC (mg)/sample (g)가 추출되어 비슷한 추출율을 보였으며 이는 기존의 유기용매 추출시 문제가 되는 용매회수와 잔존유기용매에 의한 독성 문제 등을 해결할 수 있는 추출법으로써 $SCO_2$추출이 효과적임을 알 수 있다. 또한 AITC의 $SCO_2$ 추출 시 잎과 줄기에서는 40$^{\circ}C$, 80 bar의 조건에서 가장 많은 량이 추출되었으며, 뿌리에서는 40$^{\circ}C$, 120 bar에서 가장 많은 추출량을 나타내었다. 또한 추출시간의 경우 유기용매 추출과 비교했을 때 추출시간을 줄일 수 있어 추출에 소요되는 시간을 절약할 수 있는 좋은 추출방법이다.

• 생명과학회지
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• 제9권5호
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• pp.575-580
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• 1999

Even if odorous compounds remained very low concentration in water, it caused strong odor. Because Geosmin and most of odorous compound had very vaporization, those were difficult to analyze with GC/MSD and Purge & Trap. So, we needed pre-treatment method for decreasing amounts of extracting solvents, improving recovery efficiencies and increasing analytical efficiencies. This study developed efficient technology for analyzing odorous compounds, using various adsorbents and extracting solvents. The optimum adsorbent was XAD resins. Especially, XAD-2, XAD-7 and XAD-2010 were superior, but XAD-2 of these and MTBE was the optimum extraction solvent. Other extraction solvent's efficiency was in order of MTBE>Dichloromethane>n-Hexane>Diethylether. The optimum NaCl dosage for increasing efficiency was 5g in liquid-liquid extraction method. The shaking time(0∼24hr) had no concern with adsorption efficiency. The optimum adsorbent was XAD-2 resin and extraction solvent was MTBE. Dosing NaCl, adsorption efficiency was increased in liquid-liquid extraction method, but NaCl has no effect on liquid-solid extraction method. In this experimental results, this method will apply to not only Geosmin but other well-known odorous compounds (2-MIB, IBMP, IPMP, TCA) and algae toxins (Mycrocystin, Anatoxin etc)

• 한국식품과학회지
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• 제48권2호
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• pp.111-116
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• 2016

노니 부정근 유효성분의 효율적인 추출조건을 규명하고자 용매 종류, 물과 메탄올의 비율(물, 20, 40, 60, 80, 100%), 추출시간 및 추출방법을 달리하여 실험을 진행하였다. 안트라퀴논, 페놀성 화합물 및 플라보노이드의 용매별 추출한 결과 1시간 동안 초음파 추출 시 60-80% 메탄올에서 효과적이었으며, 환류냉각 추출기로 2시간 추출 시 80% 메탄올에서 효과적이었다. 노니 부정근의 유효성분에 대한 추출방법 및 시간에 따른 추출효율을 비교하기 위하여 교반추출, 환류냉각추출, 초음파추출, 균질기추출, 초고압추출, 침지추출을 실시하였다. 페놀성 화합물은 초음파추출에서 가장 높은 함량을 보였으며 안트라퀴논과 플라보노이드 함량은 환류냉각추출에서 가장 높게 나타났다.