• 생태와환경
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• 제41권4호
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• pp.485-489
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• 2008

Algal chlorophyll-$\alpha$ is commonly determined by spectro-photometric method using 90% acetone as solvents. However, acetone has low extraction efficiency without grinding filters, and DMF (dimethyl formamide) was tested for the compatibility with acetone. Chlorophyll-$\alpha$ concentration was determined for samples from 5 reservoirs of different trophic states and phytoplankton composition, using acetone extraction with grinding and DMF without grinding. Chlorophyll-$\alpha$ measured by DMF and Acetone did not show a significant difference when using trichromatic method of UNESCO and Lorenzen, and therefore, DMF can substitute acetone. But when acidification method was applied, they showed significant difference of 8%. It can be concluded that DMF can extract chlorophylls more effectively without grinding and it can be a better alternative for the standard extraction solvent.

• Environmental Analysis Health and Toxicology
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• 제22권1호
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• pp.49-55
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• 2007

Three kind of ASE (Accelerated Solvent Extraction) and SPMDs (Semi-Permeable Membrane Devices) combined methods (ASE-SPMDs, ASE-accelerated SPMDs and SPMDs without extraction) and general Soxhlet-GPC were compared each other for the analysis of PCDD/FS in sediment. The average recovery rate of three types ASE and SPMDs combined methods (108.1%) were higher than that of the Soxhlet-GPC (79.5%) for three samples in each method using surrogate internal standards. The average coefficient of variation (10%, $2.1{\sim}25.2%$) for each congener of PCDD/Fs shows the reasonable results. Total PCDD/Fs concentrations after SPMDs without extraction were quite low, but those after ASE-SPMDs and ASE-accelerated SPMDs methods were close to the Soxhlet-GPC. Thus, the ASE-SPMDs and ASE-accelerated SPMDs methods are considered as the excellent pre-treatments method because they need less solvent and time without quality degradation.

• 한국작물학회지
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• 제44권2호
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• pp.154-158
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• 1999

Volatile flavor compounds from perilla leaves were extracted and analyzed with different methods, head-space analysis (HS), simultaneous steam distillation and extraction (SDE) , and solvent extraction (SE), and to compare their efficiencies for quick analysis. Over 30 volatile compounds were isolated and 28 compounds were identified by GC/MSD. Major compound was perillaketone showing the compositions of which were 92% in SDE method, 86% in headspace analysis, and 62% in solvent extraction method. For quick evaluation of leaf flavor in perilla, it was desirable because the headspace analysis method had a shorter analyzing time and smaller sample amount than the other methods.

• 대한화학회지
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• 제56권1호
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• pp.58-61
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• 2012

The solvent extraction of platinum (IV) metal from hydrochloric acid media using 4-(4-ethoxybenzylideneamino)-5-methyl-4H-1,2,4-triazole-3-thiol (EBIMTT) in chloroform was studied as a function of several variables, such as reagent, acid and metal ion concentration, effect of various diluents, and diverse ions. The proposed method was further applied for the separation of platinum (IV) from binary mixtures, synthetic mixtures, alloys and commercially available samples.

• 생약학회지
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• 제30권1호
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• pp.59-64
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• 1999

Supercritical fluid extraction (SFE) technique was applied to extract cytotoxic substances from five medicinal plants including Angelica gigas, Angelica acutiloba, Aralia cordata, Spirodela polyrhiza, Bupleurum falcatum, and Acanthopanax sessiliflorus. The cytotoxicities against P388, A549, and HL-60 cell lines were determined for the supercritical carbon dioxide extracts of five plant materials employed and were compared with those of the conventional organic solvent extracts such as n-hexane, $CHCl_{3}$, and MeOH to evaluate the SFE as an alternative method to conventional organic solvent extraction. In most cases, the SFE extracts of plant materials showed enhanced cytotoxicities when compared with those of other organic solvent extracts. In addition, the optimum temperature and pressure of SFE for extraction of the cytotoxic substances were largely affected by both the plant species and the cell lines tested. These results suggested that SFE could be an alternative to the conventional organic solvent method for the selective extraction of cytotoxic compounds from plants.

• 신재생에너지
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• 제19권4호
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• pp.27-34
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• 2023

In this study, microalgal oil was extracted from Nannochloropsis oceanica cultured in an open raceway pond and converted into biodiesel using a solid acid catalyst. Microalgal oil was extracted from two types of microalgae with and without nitrogen starvation using the KOH-solvent extraction method and the fatty acid content and oil extraction yield from each microalgae were compared. The fatty acid content of N. oceanica was 184.8 mg/g cell under basic conditions, and the oil content increased to 340.1 mg/g under nitrogen starvation conditions. Oil extraction yields were 90.8 and 95.4% in the first extraction, and increased to 97.5 and 98.8% after the second extraction. Microalgal oil extracted by KOH-solvent extraction was yellow in color and had reduced viscosity due to chlorophyll removal. In biodiesel conversion using the catalyst SO₄^2-/HZSM-5, solvent-extracted oil showed a FAME content of 4.8%, while KOH-solvent-extracted oil showed a FAME content of 90.4%. Solid acid catalyst application has been made easier by removal of chlorophyll from microalgal oil. The FAME content increased to 96.6% upon distillation, and the oxidation stability increased to 11.07 h with addition of rapeseed biodiesel and 1,000 ppm butylated hydroxyanisole.

• 청정기술
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• 제13권4호
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• pp.274-280
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• 2007

본 연구에서는 염화 제2철 수용액의 재생 공정에 주로 쓰이고 있는 철환원법을 대체하기 위한 방법으로, 액-액 용매 추출법을 사용하여 수용액 내에 잔존해 있는 중금속인 Fe와 Ni을 분리 회수하는 공정을 개발하였다. Lab 실험을 통해 우선 염화 제2철 수용액으로부터 선택적으로 염화 제2철만을 추출할 수 있는 용매조건을 개발하였고, 그 결과를 사용하여 액-액 추출공정의 상업화 추진을 위한 pilot 공정 및 장치를 개발하였다. 또한 pilot test를 통하여 추출단과 역추출단의 단수를 결정할 수 있었고, 양산 공정에 적용할 수 있는 공정 데이터를 확보하였다.

• 분석과학
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• 제14권2호
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• pp.103-108
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• 2001

희토류원소를 tri-n-butyl phospate와 질산염을 이용하여 용매추출하고 물로 역추출하여, 희토류원소의 군분리 효율을 조사하고 ICP-AES에서 스펙트럼의 방해영향이 없는 분석을 시도하였다. 용매추출시 분배계수를 증가시키기 위하여 $NaNO_3$ 농도에 따른 영향을 조사하고, 소수성 용매의 첨가시 추출효율을 조사하였다. $NaNO_3$ 농도가 증가할수록 추출효율은 증가하며, 5M 이상에서 추출효율이 95% 이상으로 높았다. 반면에 소수성용매의 첨가는 추출효율을 감소시켰다. 이 방법을 모나자이트 중 희토류원소의 분석에 이용하였으나 분석결과의 정밀도가 20% 이상으로 높아 분석에 이용하기에는 어려움이 있었다.

• 한국식품영양과학회지
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• 제45권8호
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• pp.1162-1169
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• 2016

본 연구에서는 기능성 홍삼 엑기스 제조를 위해 추출용매, 압력, 온도, 추출시간을 조절하여 가속 용매 추출한 후 기능성 홍삼제품의 지표성분인 진세노사이드 함량, 총페놀화합물 및 벤조피렌 함량 등을 조사하였다. 홍삼 가속 용매 추출 최적화를 위한 독립변수 선택을 위해 에탄올 농도, 압력, 온도 및 추출시간에 따른 기능성 홍삼제품의 지표성분인 진세노사이드 Rb1, Rg1 및 Rg3(20S) 함량의 합을 분석하여 진세노사이드 추출에 가장 최적의 용매를 50% 에탄올로 하고, 영향이 다소 작았던 요인인 압력을 2,500 psi로 설정하였으며, 온도와 추출시간을 독립변수로 설정하였다. 추출 온도 및 시간을 독립변수로 하여 고온고압 처리한 홍삼의 진세노사이드 Rb1, Rg1 및 Rg3(20S) 함량의 합, 총 페놀성 화합물 및 벤조피렌 함량을 측정한 결과, 벤조피렌이 검출되지 않는 조건에서 진세노사이드 Rb1, Rg1 및 Rg3(20S)의 함량 합이 최적화된 조건은 $158^{\circ}C$, 20분임을 확인할 수 있었다. 최적화된 조건에서의 가속 용매 추출 시 초음파 및 환류냉각 추출에 비해 적은 용매로 단시간 추출하면서 진세노사이드 Rb1, Rg1 및 Rg3(20S) 함량 합 및 총폴리페놀 함량이 각각 1.5~2배 및 2.2~5배 높게 추출할 수 있어 효율적인 추출방법이 될 것으로 생각된다.

• Journal of Radiation Protection and Research
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• 제21권1호
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• pp.9-16
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• 1996

환경시료 중 토양에 대한 방사성 스트론튬인 $^{89}Sr$와 $^{90}Sr$의 분석을 위해 Ca과 Sr을 분리하기 위한 방법으로 Crown ether를 이용한 추출방법을 사용하여 기존의 발연질산법과 비교하여 보았다. Crown ether를 이용한 추출방법을 기존의 발연질산법과 비교하여 보았을 때 높은 Sr 수율을 보였을 뿐만 아니라 분석에 소요되는 시간과 절차가 훨씬 빠르고 간단했다. Crown ether을 이용한 추출방법으로 원전주변 토양에 대한 방사성 스트론튬의 분석을 수행하였으며, 방사성핵종 분석에 의한 환경감시의 효율적인 수행을 위한 스트른튬 분석법을 제시하였다