• 한국환경보건학회지
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• 제25권3호
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• pp.103-107
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• 1999

Even if odorous compounds remain very low concentration in water, it cause strong odor. Because Geosmin and most of odorous compound had very low 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 the optimum extraction solvent is MTBE. Other extraction solvents' efficiency is in order of MTBE>Dichloromethane>n-Hexane>Diethylether. The optimum NaCl dosage for increasing efficiency is 5 g in liquid-liquid extraction method. The shaking time(0~24hr) has no concern with adsorption efficiency. The optimum adsorbent is XAD-2 resin and extraction solvent is MTBE. Dosing NaCl, adsorption efficiency is increased in liquid-liquid extraction method, but NaCl has no effect on liquid-solid extraction method. In this experimental results, this algae toxins(Mycrocystin, Anatoxin etc.).

• 한국연초학회지
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• 제36권1호
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• pp.26-33
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• 2014

Simultaneous determination of crop protection agents(CPAs) in food are done with multi-residue methods, which are composed of sample clean-up, concentration, chromatographic separation and detection. Stir Bar Sorptive Extraction(SBSE) technique is used for sample preparation of various analytes in several fields. The aim of this study was to develop a sensitive and fast method based on SBSE followed by thermal desorption - gas chromatography - mass spectrometry(TD - GC/MS) to determine CPAs in tobacco sample. For the analysis of tobacco sample prior to the SBSE method, solvent extraction or ultrasound-assisted solvent extraction was performed. methanol was used as the extraction solvent. The extract was then diluted with water. Finally, the sample was subjected to SBSE. A method for fast screening of crop protection agents in tobacco using SBSE-TD - GC/MS has been developed. About 17 CPAs including organochlorine, organophosphorous and others were identified and quantified. This method showed good linearity and high sensitivity for most of the target CPAs. The method was applied to the determination of CPAs at ng/mL levels in tobacco sample. This method is simple, rapid and may be applied in detection of other components.

• 폴리머
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• 제32권1호
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• pp.13-18
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• 2008

전기 전자재료 중 고분자에 포함된 브롬계 난연제의 분석에 있어 용출이 어려운 4가지 재질 PC(polycar-bonate) PP(polypropylene), PET(poly(ethylene terephthalate)), PBT(poly(butylene terephthalate))에 대하여 추출방법 및 헥산/에세톤, THF, 톨루엔, THF/톨루엔에 대한 용매 특이성과 그 특성을 고찰하였다. 각 고분자에서의 deca-BDE(decabromo diphenyl ether)의 함량을 속슬렛, 초음파. 가속용매, 마이크로파, 초임계 유체 추출법을 사용하여 이들 방법의 효율을 정량분석 하였다. 초음파 추출은 낮은 고분자의 용해도 때문에 낮은 추출효율을 보여 사용한 고분자의 경우에 있어서 추출방법으로는 적합하지 않았으며, 나머지 3가지 방법에서는 톨루엔 사용시 약 80% 이상의 높은 추출효율을 보였다. 초임계 유체 추출은 고분자의 난연제 추출에 시도되지 않았던 방법이었으나, 본 실험에서 PP와 PC의 추출에서는 100%에 가까운 매우 높은 추출효율을 보였다.

• 산업기술연구
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• 제27권B호
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• pp.161-167
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• 2007

The objetives of this study are to set up optimum extraction temperature, time and organic solvent for propolis extraction, to investigate chemical properties, and to develop health foods from propolis preparation. In this study, ethanol and ultrasonic extracts method performed to optimum extraction temperature was at 60, $20^{\circ}C$, optimum extraction time was at 12, 4 hours and optimum extraction amount of solvent was at 20, 15 times of propolis weight. When various ethanol solutions were used, whereas flavonoid content was highest in 70, 80% aqueous ethanol, respectively. So the ultrasonic extracts method used gave better results than the ethanol extracts method in this work. Extraction of propolis with etanol and ultrasonic extracts method was performed by using the water and various concentrations of aqueous ethanol as solvent. Sensitivity of propolis samples to Staphylococcus aureus was investigated and the results were shown. Samples of water extract did not inhibit microbial growth, where as 50% aqueous ethanol extract the largest inhibitory zone for Staphylococcus aureus, then decreased inhibition with increasing ethanol concentrations.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3196-3202
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• 2012

Post-synthesis is used to synthesize organic hybrid inorganic mesoporous sieves. In this method, the activity and structure of the base sieve are crucial to obtain the definable hybrid materials. The chemical and physical properties of the base can be largely changed either by the final step of its synthesizing processes, by template removal which is accomplished with the oxidative thermal decomposition (burning) method or by solvent extraction method. In this paper we compared two methods for the post-synthesis of organic hybrid MCM-48. When the template was extracted with HCl/alcohol mixture, the final product showed larger pore size, larger pore volume and better crystallinity compared to the case of the thermal decomposition. The reactivity of the surface silanol group of template free MCM-48 was also checked with an alkylsilylation reagent $CH_2=CHSi(OC_2H_5)_3$. Raman and $^{29}Si$ NMR spectra of MCM-48 in the test reaction indicated that more of the organic group was grafted to the surface of the sample after the template was removed with the solvent extraction method. Direct synthesis of vinyl-MCM-48 was also investigated and its characteristics were compared with the case of post-synthesis. From the results, it was suggested that the structure and chemical reactivity can be maintained in the solvent extraction method and that organic grafting after the solvent extraction can be a good candidate to synthesize a definable hybrid porous material.

• KSBB Journal
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• 제15권4호
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• pp.346-351
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• 2000

식물세포 배양액으로부터 회수한 식불세포 내 수분 함 량에 따른 추출효율은 건조 정도 보다는 건조방법 에 상당 히 영향을 받음을 알 수 있었으며 건조하여 추출할 경우 사용되는 추출용매를 절약할 수 있었다. 여러가지 유기용 매를 이용하여 paclitaxe1의 추출 경향을 조사한 결과 메탄올의 경우 가장 적 은 양으로 가장 높은 paclitaxe1 회 수율을 얻어 가장 효과적임을 알 수 있었다. 추출방법의 경우 counter-current 형태를 사용할 경우 batch형태에 비하여 용 매 사용량을 줄일 수 있으며 paclitaxe1 회수율은 거의 차이가 없음을 알 수 있었다. Batch 형태를 이용한 메탄올 추출시 식불세포의 경우 4회 (회수율>99%), 식불세포조각의 경우 1회 (회수융>96%)의 추출로 대부분의 paclitaxe1 회수가 가능 하였다. 또한 메탄올 추출시 90% 이상의 머탄올 농도이변 충분하며 (회수율>98%), 추출시biomass와 메탄올 의 흔합비 (Kg biomass: L MeOH)는 1: 1, 추출시간은 1회 5분 이상이면 적당 하였다. 메탄올 추출불에 포함된 극성불 순물들은 다음 공정 인 액/액 (methylene chloride/ MeOH)추 출로 제거하여 정제공정에 사용되어 진다.

• KSBB Journal
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• 제19권6호
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• pp.421-426
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• 2004

토종콩으로부터 비배당체 이소플라본을 추출하기 위한 다양한 기계적 및 화학적 방법을 적용하였다. 용매추출법의 침적과 교반, 초음파에너지와 아임계/초임계 수 추출이 포함되었다. 용매의 조성에 의한 추출효율의 증가, 교반에 의한 특정성분의 추출효과의 증대, 초음파에너지에 의한 추출성능의 개선, 용매보다 용해력이 좋은 초임계유체의 적용에 관한 실험을 수행한 결과에 의하면 비배당체 이소플라본의 추출은 초음파에너지에 의한 것이 가장 우수하였다.

• 한국환경과학회지
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• 제6권2호
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• pp.133-139
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• 1997

말로네이트 제조 공정에서 발생되는 폐액으로부터 용매추출법을 적용하여 코발트 회수 연구를 하였다 용매 추출에서의 주요 변수는 용매의 선택, pH, 코발트 농도, 역추출 온도 등이며 이러한 변수들의 영향을 조사하였다. 용매로써 DEHPA와 PC88A가 사용되었으며 이들 용매의 평형추출 곡선을 구하였다. 공장설계 조건을 찾기 위하여 Mccabe-Tiele 선도를 작성하였고, 연속 공정인 믹서-세틀러 장치를 가동하였다. 본 연구 결과 폐액 중에서 코발트는 99.9% 이상 회수되었고, 회수된 황산코발트의 순도는 99.9% 이상이었다.

• Natural Product Sciences
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• 제19권2호
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• pp.166-172
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• 2013

Caffeine and epigallocatechin gallate (EGCG) are major constituents of green tea, the leaves of Camellia sinensis (Theaceae). Although EGCG is well known for diverse beneficial effect, caffeine is sometimes harmful with adverse effects. Therefore, the extraction efficiency was investigated using different extraction method such as extraction solvent, extraction time, extraction method, and repeated extraction. The content of EGCG and caffeine in green tea extract was quantitated by HPLC analysis. The extraction condition exerted difference on the extraction yield. The content of EGCG was also affected by different extraction condition. Especially, the extraction solvent greatly affected the content of EGCG in the extract. However, the content of caffeine was less affected compared to that of EGCG. The inhibitory effect of green tea extract on pancreatic lipase was almost similar regardless of extraction condition. Taken together, optimization of extraction condition will provide best efficacy for further development of green tea as anti-obesity therapeutics.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권1호
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• pp.42-46
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• 2012

The ISO document of ISO/TC/190/SC3/WG11/N11 is a working draft of international standard (WD) dealing with analytical method for the determination of explosives and related compounds using high performance liquid chromatography. The scope of this WD covers the storage of samples, preparing test portion, extraction and instrumentation. The main purpose of this study was to improve the extraction conditions which were already adopted in the WD. For this purpose, mechanical shaking method could be corresponded up to 18 hours of ultrasonic bath extraction in the WD was tested. Methanol was also tested with the intention of being added as an extracting solvent other than acetonitrile in the WD. According to the results, 16 hours of mechanical shaking method showed statistically the same effectiveness as that of 18 hours of ultrasonic bath extraction. In case of extracting solvent, methanol also showed statistically the same extraction capability as acetonitrile for DNB, TNT, 2-A-DNT and 2,4-DNT. However, the recovery rate of TNB with methanol extraction was 40% higher than that of acetonitrile extraction. Through adding mechanical shaking method into committee draft (cf. the next stage draft of the WD during the process for making international standard), ISO standard of analyzing explosives and related compounds in soil would become more useful in dealing with huge number of field samples in the laboratory. In other aspect, adopting methanol as an alternative extracting solvent would be very effective in the terms of exchangeability with GC-ECD/MS method which is being developed by German experts.