• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2687-2690
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• 2009

Due to the importance of isoflavone content in soybean extracts, the microwave-assisted process (MAP) was compared to the conventional extraction methods. For comparison of the three methods, all extraction parameters (solvent, sample to solvent ratio, temperature, etc.) were kept the same; the microwave extractor was operated at 187.5 W with an emission frequency of 2450 MHz under atmospheric pressure conditions and the extractions were carried out at 75 ${^{\circ}C}$ for 3 min while the conventional reflux was at 75 ${^{\circ}C}$ for 3 h. Total yield and crude isoflavone content were determined by ultraviolet spectrophotometric and compared with the three methods. Results indicated that the MAP was comparable to the conventional method in its capability to extract target compounds without causing any degradation; in addition it dramatically reduced the extraction time from 3 h to a few minutes, suggesting that it can be an alternative technique to the time-consuming conventional reflux method.

• Analytical Science and Technology
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• v.8 no.3
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• pp.237-248
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• 1995

The simultaneous analysis of 16 organic pesticides, which are listed as a part of 129 priority pollutants by EPA(Environmental Protection Agency), was performed by GC-ECD(electron capture detector) and GC/MS-SIM(selected ion monitoring). Two extraction procedures from SW-846, sonication extraction and Soxhlet extraction, were somewhat modified and compared as an extraction and concentration method for the analysis of priority pollutants in soil. Accuracy and precision of the methods were reported from the calculation of mean recovery, mean relative standard deviation, and method detection limit.

• The Korean Journal of Food & Health Convergence
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• v.5 no.5
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• pp.11-25
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• 2019

Extraction of oil from Moringa oleifera seed using Response Surface Methodology (RSM) was investigated. Effects of three factors namely: sample mass, particle size and extraction time on the response, Moringa oleifera a volume extracted, were determined. The Box-Behnken design of RSM was employed which resulted in 15 experimental runs. Extraction was carried out in a 250 ml Soxhlet extractor with Hexane and Ethanol as solvent. The Moringa oleifera seed powder was packed inside a muslin cloth placed in a thimble of the Soxhlet extractor. The extraction was carried out at 60℃ using thermostatic heating mantle. The solvent in the extracted oil was evaporated and the resulting oil further dried to constant weight in the oven. This study demonstrates that Moringa oleifera oil can be extracted from its seed using ethanol and acetone as extraction solvent. The optimum process variables for both solvent (ethanol and acetone) was determined at sample weight of 40 g, particle size of 325 ㎛ and extraction time of 8 hours. It can be deduced that using acetone as solvent produces a higher yield of oil at the same optimum variable conditions compared to when ethanol was used.

• Carbon letters
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• v.24
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• pp.10-17
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• 2017

With continuous development in the field of sample preparation technology, solid phase micro-extraction (SPME) has been widely used in analytical chemistry for high extraction efficiency and convenient operation. Different materials lead to different extraction results. Among existing materials, carbon-based materials are still attracting attention from scientists due to their excellent physical and chemical properties as well as their modifiable surfaces, which could enhance the adsorption effects of SPME fiber. This review introduces the preparation methods and applications of different kinds of carbon-based material coatings on fibers. In addition, directions for future research on carbon material composites are discussed.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.207-211
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• 2004

Predispersed solvent extraction (PDSE) of succinic acid with Tri-n-octylamine (TOA) dissolved in 1-octanol from aqueous solutions of 50 g/L succinic acid was examined. It was found that the equilibrium data in PDSE was equal to that in conventional solvent extraction in spite of the lack of mechanical mixing in PDSE. The influence of salts on succinic acid extraction and the stability of colloidal liquid aphrons (CLAs) were also investigated. Results indicated that in the presence of sodium chloride, less succinic acid was extracted by CLAs and the stability of CLAs decreased. However, the stability of CLAs was sufficient to make PDSE practically applicable to real fermentation broth, considering the concentration range of salts in the fermentation process for succinic acid.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1463-1464
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• 2011

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3107-3110
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• 2014

• Bulletin of the Korean Chemical Society
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• v.23 no.7
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• pp.935-936
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• 2002

• Bulletin of the Korean Chemical Society
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• v.22 no.3
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• pp.321-324
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• 2001

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1495-1500
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• 2003

Equilibria and applications of a synergistic extraction were studied for the determination of a trace lithium by using thenoyltrifluoroacetone (TTA) and trioctylphosphine oxide (TOPO) as ligands. Several equations were derived for the extraction of lithium into m-xylene as a phase of Li-TTA·mTOPO adduct. Distribution coefficients and extraction constant were determined together with a stability constant of the adduct. The adduct was quantitatively extracted from the basic solution of higher than pH 9 by shaking for 30 minutes. m-Xylene was selected as an optimum solvent by comparing the extraction efficiency among several kinds of organic solvents. The stability constant (${\Beta}_2$) for Li-TTA/2TOPO was 150 times higher than Li-TTA/TOPO. The distribution coefficient of Li-TTA/2TOPO into m-xylene was 9.12 and the logarithmic extraction constant (log $K_{ex}$) was 6.76. Trace lithium of sub-ppm level in seawater samples could be determined under modified conditions and a detection limit equivalent to 3 times standard deviation for background absorption was 0.42 ng/mL.