• Journal of Radiation Protection and Research
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• v.21 no.1
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• pp.9-16
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• 1996

For the determination of radiostrontium, $^{89}Sr\;and\;^{90}Sr$ in environmental soil sample, a solvent extraction method for the separation of Ca and Sr from matrix using crown ether was investigated. In comparison with the existing fuming nitric acid method, the extraction method showed high chemical yield of strontium and provided simple and rapid analytical steps. The new analytical method applied to the determination of radiostrontium in some soil sample around a nuclear power station to show that the analytical procedure is readily applicable to the practical radioactivity monitoring.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.196-200
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• 2003

A gas chromatography/mass spectrometric assay method was developed for the simultaneous determination of ethylene glycol monomethyl ether (EGME) and diethylene glycol monomethyl ether (DEGME) in spilled aviation fuels. Ethylene glycol monobutyl ether (EGBE) and ethylene glycol monoethyl ether (EGEE) were used as internal standard and surrogate, respectively. The sample preparation consists of back-extraction with 7 mL of methylene chloride after extraction of 50 mL of fuel with 2 mL of water. The extract was concentrated to dryness and dissolved with 100L of methanol and analyzed by CC-MS (SIM). The peaks had good chromatographic properties by using semi-polar column and the extraction of these compounds from fuel also gave high recoveries of 75 and 85 % with small variations for EGME and DEGME, respectively. Method detection limits were 1.3 ng/mL for EGME and 1.0 ng/mL for DEGME in spilled fuel. The method may be useful for fuel-type differentiation between kerosene and JP-8, which may originate from the storage tank.

• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1315-1322
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• 2006

The following study describes the gas chromatography-mass spectrometry (GC-MS) based screening and confirmation analysis of urinary androgenic steroids. Four commercially available solid-phase extraction (SPE) cartridges, Serdolit PAD-1, Sep-pak $C_{18}$, amino-propyl, and Oasis HLB, and three different extractive organic solvents, diethyl ether, methyl tert-butyl ether (MTBE), and n-pentane, were tested for sample preparation. Overall, Oasis HLB combined with MTBE extraction provided the highest recoveries in 39 of 46 total androgenic steroids examined and it showed a good extraction yield (>82.1%) for polar steroids, such as metabolites of fluoxymesterone, oxandrolone, and stanozolol, which gave a poor recovery in both n-pentane (9.2-64.3%) and diethyl ether (22.2-73.6%) extractions. All SPE sorbents tested showed potential, because they were efficient in extraction for most or selective steroids. When applied to positive urine samples based on the results obtained, the present method allowed selective and sensitive analysis for detection of urinary androgenic steroids. The experiments showed that the high-resolution MS method is clearly more efficient than the low-resolution MS technique for the detection of many urinary steroids. However, comprehensive sample clean-up procedures also might be needed especially in confirmation analysis to increase detectability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1923-1926
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• 2015

This study was conducted to evaluate the effects of extraction conditions on tricin and tricin 4'-O-(threo-${\beta}$-guaiacylglyceryl) ether (TTGE) extracted from rice hull (Oryza sativa L.). Extraction conditions were an ethanol concentration of extraction solvent of 50~90%, extraction time of 0.5~48 h, and ultrasonic-assisted and agitated extraction as extraction methods. The total tricin and TTGE contents of rice hull were $82.20{\mu}g/g$ and $53.12{\mu}g/g$, respectively. Recovery of tricin and TTGE increased to 76.11% and 71.42% with increasing ethanol concentration until 70% and then decreased above 80%, respectively. In ultrasonic-assisted extraction, highest recovery of tricin was 83.30% after 2 h of extraction and TTGE was 71.80% after 1 h of extraction. In agitated extraction, highest recovery of tricin was 92.34% after 48 h and TTGE was 76.89% after 24 h of extraction. Therefore, optimum extraction conditions for tricin and TTGE of rice hull were 70% ethanol concentration and ultrasonic-assisted extraction for 1 h.

• The Korean Journal of Food And Nutrition
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• v.14 no.1
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• pp.20-27
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• 2001

The consumption of radish ( Rhaphanus sativus L.) sprout, which is Cruciferae family, is increasing because of its pungent flavor and taste. Its volatile components were analyzed by SDE (simultaneous steam distillation & extraction) method and P&T(purge & cryogenic trapping) method. As a solvent, diethyl ether and diethyl ether : pentane mixture(2:1, v/v) were used in SDE method, and diethyl ether in P&T method. Analyzing by GC and GC-MS, the major component was sulfur compounds (19 species, peak area 76.6%) with diethyl ether, sulfur compounds(15. 44.0%) and hydrocarbons(23, 23.8%) with diethyl ether-pentane mixture in SDE method. Also, hydrocarbons(25, 84.1% ) was major component in P& T method. The major volatile component of fresh radish sprout were n-heptane, methyl pentane and that of boiled radish sprout were 4-methylthio-3-butenyl isothiocyanate, methyl mercaptane, 2,3-dimethyl disulfide. Low molecular volatile components were detected more by P& T method, but types and relative quantities of volatile components were measured less comparing to SDE method.

• Journal of the Korean Chemical Society
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• v.29 no.5
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• pp.496-502
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• 1985

The solvent extraction and cleanup processes for the simultaneous gas-liquid cliromatographic determination of 16 kinds of organochlorine pesticide residues were investigated. The pesticides were extracted out from-various crops with the aqueous acetone solution acidified (pH < 1.5) by adding conc. $H_3PO_4$. Most of the pesticides were partitioned from the solution with petroleum ether. Evaporated the extracting solvent, the residues were dissolved in ethylether-petroleum ether (6 : 94) eluent and eluted through the Florisil column activated at 650$^{\circ}$C for 2.5hrs. The extraction efficiency was over 94% and impurities were effectively removed by the column chromatography.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.143-146
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• 1990

Yellowish and oily crude gingerol extract was obtained from ginger(Zingiber officinale rose)by ether, ether and hexane extraction. The major component was identified by TLC analysis to be gingerol. The crude gingerol extract thus obtained was found to have antioxidant activity. The crude gingerol extract showed a synergistic antioxidant activity when combined with citric acid. The maximum synergistic effect was observed at 0.04% citric acid. The activity of the antioxidants used was found to increase in the order of BHT, crude gingerol plus 0.04% citric acid, crude gingerol, BHA and tocopherols.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.609-613
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• 2004

This study was investigated on antioxidant activities of water, methanol and ether extracts of clove. The extraction yields of water, methanol and ether extracts were 34.7, 21.4 and 17.0%, respectively. Total phenolic contents of water, methanol and ether extracts were 23.1, 55.7 and 34.9%, respectively. Eugenol contents were 6.1 and 8.1% in methanol and ether extracts, but it was not detected in water extract. Electron donating abilities of water, methanol and ether extract were 36.1, 30.9 and 29.7%, respectively. In linoleic aicd system, the ether extract showed more high antioxidant activity than water and methanol extracts. The antioxidant activity of ether extract was almost equal that of $\alpha$-tocopherol, but weaker than that of BHT In linoleic acid emulsion system, the water extract showed higher or stronger antioxidant activity than methanol and ether extracts. Antioxidant activities in linoleic acid emulsion substrates were in order of BHT ＞water extract＞methanol extract＞ether extract＞ $\alpha$-tocopherol.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.2
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• pp.88-94
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• 2010

The ether extract(EE) of leaf tobacco contains diverse compounds such as lipid, resinoid, paraffin hydrocarbons and pigments. Although the correlation of EE concentertion with leaf tobacco has not been established clearly, it is known that in some concentration range, EE concentration of leaf tobacco exerts good influence on the quality of tobacco. Recently, The American Oil Chemist's Society introduced new method(Am 5-04; AOCS, 2009) to determine EE concentration by AT15 extractor. This method is based on extraction with organic solvent at relatively high temperature and pressure, which significantly reduces the extraction time and ensures safety. The aim of this study is to optimize analytical condition of AOCS method for analyzing EE concentration of leaf tobacco. When sample pre-drying time and extraction time of XT15 were set to 3 hour and 30 minute and 30 minute respectively, EE concentration obtained from AOAC method. Statistical analysis(T-test) showed that there is no difference(P>0.05) between EE concentrations from two methods.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.305-308
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• 2000

This study was observed to the effect of the feeding Platycodon grandiflorum A. DC (3 years) extract on the bronchus diseases bacteria ( C. diphtheriae, S. aureus, Mycobacterium sp., F. nucleatum, S. pygogenes, K. pneumoniae and N. gonorrhoeae) and fungi(A. fumicatus). Platycodon grandiflorum A. DC was extracted ethanon, water, ethyl ether and petroleum ether. The extraction rate of Platycodon grandiflorum A. DC to the extract solution was identified 71.8%, 100%, 15.4% and 14.1%. Each extract solution was injected culture media into several concentrations and then investigated the bacteria cell growth during 32 hours. As a result antimicrobial activity was excellent an extract by ethyl ether and petroleum ether. Among several concentrations, bacteria cell growth inhibition was observed from 0.06% to 0.14%. The rate of antimicrobial activity was over 70%. The cell growth inhibition rate of each bacteria was appeared in order of ethyl ether > petroleum ether > water > ethanol.