• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.822-826
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• 1996

Volatile flavor components from various edible portions of Capsella bursa-pastoris were collected by simultaneous steam distillation-extraction (SDE) method using diethyl ether as solvent. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Thirty four volatile flavor components, including 12 hydrocarbons, 2 aldehydes, 2 ketones, 5 alcohols, 1 ester, 10 acids and 2 miscellaneous ones were confirmed in whole samples. Thirty one components, including 11 hydrocarbons, 5 aldehydes, 4 ketones, 5 alcohols, 1 esters and 5 miscellaneous ones were confirmed in leaves. Twenty four components, including 5 hydrocarbons, 1 aldehyde, 2 ketones, 6 alcohols, 2 esters, 1 acid and 7 miscellaneous ones were confirmed in roots. The kinds and amounts of volatile flavor components revealed different patterns depending upon various edible portions. Relatively greater numbers of volatile flavor components were identified in leaves compared with roots of these wild plants. The characteristic aroma of Capsella bursa-pastoris appeared to be due to combination of C6 alcohol and acids, terpene alcohol and sulfur containing compounds.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.814-821
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• 1996

An attempt was made to determine the effects of drying methods including shady air drying, presteamed and shady air drying, microwave drying, and freeze drying on the volatile flavor components of Capsella bursapastoris. Essential oils from the samples were isolated by Simultaneous steam distillation-extraction (SDE) method using diethyl ether as solvent. Concentrated samples were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Respective 30, 18, 29, and 26 volatile flavor components were identified in shady air dried samples, presteamed and shady air dried samples, microwave dried samples, and freeze dried samples. The kinds and amounts of volatile flavor components evidently depended upon the drying methods. Trimethyl sulfide was regarded as the most abundant component in shady air dried samples, dimethyl trisulfide in presteamed and shady air dried samples, and phytol in microwave or freeze dried samples.

• Journal of the Korean Chemical Society
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• v.21 no.5
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• pp.372-378
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• 1977

The following new techniques have been developed: (A); To a 500ml of sample water, it was adjusted pH 10 with ammonia-anmonium citrate, added 10ml of 1${\%}$ sodium diethyldithiocarbamate and extracted three times with 10ml of CHCl3. The extract was shaken with 10ml of 0.05N $HCl-4{\times}10^{-4}M\;HgCl_2$. The aqueous solution was added 2ml of 2N KCl and washed two times with 10ml of pure $CHCl_3$, and then recorded square wave polarograms. (B); To a 500ml of sample water adjusted pH 10 with ammonia-ammonium citrate, it was added 2ml of 1${\%}$ 8-hydroxyquinoline and extracted three times with 10ml $CHCl_3$. The separated $CHCl_3$ phase was shaken with 10ml of 0.2 N HCl. The aqueous solution was recorded polarograms directly. These methods can be used for determination of the ppb order of metal in water with an error of ${\pm}10{\%}$. The method (B) can not be used for the determination of zinc on account of the free 8-hydroxyquinoline.

• Journal of the Korean Chemical Society
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• v.37 no.11
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• pp.961-966
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• 1993

The determination of noble metals such as Ir, Au and Ag in the ancient coins has been studied. For the measurement of the activity of $^{192}Ir,\;^{198}Au\;and\;^{110m}Ag$, radiochemical separations including solvent extraction and ion-exchange chromatography were applied to reduce the interference of high energy ${\gamma}$-ray emitted from various radionuclides with long half-life. As a results, $10^{-11}$ g/g level of Ir could be detected and it was found that the three kinds of the detection limits, i.e., critical, detection, quantitative limit, calculated by the method proposed by Currie, were enhanced. Prior to the re-irradiation with neutron, inactive carrier was added in order to determine the recovery yield of Ir in the radiochemical separation. The average recovery yields of Ir, Au and Ag in the 5 coins were 65.3%, 98.5%, 99.5%, respectively.

• Korean journal of food and cookery science
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• v.14 no.5
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• pp.541-546
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• 1998

Volatile flavor components in leaf and petiole of fresh Pleurospermum kamtschaticum H$\_$OFFM/ were extracted by SDE (simultaneous steam distillation and extraction) method using diethyl ether as solvent. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Identification of volatile flavor components was based on the Rl of GC and mass spectrum of GC-MS. A total of 31 components, including 15 hydrocarbons, 4 aldehydes, 1 ketone, 5 alcohols, 2 esters, 3 acids and 1 oxide were identified in the essential oils. (Z)-${\beta}$-Farnesene, (Z, E)-${\alpha}$-farnesene and farnesene were the major volatile flavor components in fresh Pleurospermum kamtschaticum. Volatile flavor patterns of Pleurospermum kamtschaticum were analyzed using electronic nose. Sensor T30/1 and PA2 that were sensitive to alcohols had the highest resistance for fresh Pleurospermum kamtschaticum. Resistance of six metal oxide sensors was decreased in dried sample compared with fresh one.

• Korean journal of food and cookery science
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• v.14 no.5
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• pp.547-552
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• 1998

Essential oils in leaf of fresh Aster glehni were extracted by SDE (simultaneous steam distillation and extraction) method using diethyl ether as solvent. The yield of the essential oils was 0.05%. And their volatile flavor components were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) and identified by the RI of GC and mass spectrum of GC-MS. A total of 31 components, including 17 hydrocarbons, 2 aldehydes, 7 alcohols, 3 esters, 1 acid and 1 oxide were identified. The major volatile flavor components of fresh Aster glehni were ${\alpha}$-pinene, limonene, $\delta$-elemene, ${\beta}$-pinene, cis-3-hexenol and myrcene. Volatile flavor patterns of fresh ind dried Aster glehni were analyzed using an electronic nose. Sensor PA2 that was sensitive to alcohols showed the highest resistance for fresh and dried Aster glehni. Resistance of six metal oxide sensors was decreased in fresh sample compared with dried one.

• KSBB Journal
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• v.23 no.2
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• pp.125-130
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• 2008

We investigated the biological activities of ethanol extract from the seawater algae, Chlorella elliposidea C020 such as antibacterial activity, anti-oxidant activity, tyrosinase inhibitory activity and hemolytic activity against human erythrocytes. Extract was obtained from various solvent, methanol, ethanol, acetone and ethanol + acetone (1:1, v/v%), 95% ethanol proved to be best extraction solvents. The contents of ethanol extract were higher in freeze-dried sample than that in frozen-thawing. Antibacterial activities of ethanol extract showed strong inhibitory effect against Bacillus subtilis PM125, Bacillus licheniformis and fish pathogenic bacteria, Vibrio parahaemolyticus KCTC2471 and Edward tarda NUF251. However, this extract didn't worked against antifungal activity against Candida albicans KCTC1940. And, ethanol extract was without hemolytic activity against human erythorocytes. The ethanol extract showed 75% of free radical scavanging effect on 2.0 mg/mL using DPPH method. In tyrosinase inhibition assay of ethanol extract, $IC_{50}$ (Inhibition Concentration) was measured as 10.87 mg/mL. Conclusionally, ethanol extract of Chlorella elliposidea C020 has good candidate for bioactive materials.

• Journal of Powder Materials
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• v.18 no.3
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• pp.262-268
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• 2011

In order to investigate the microstructure and mechanical properties of WC-10 wt% Co insert tool alloy fabricated by PIM (Powder Injection Molding) process, the feedstock of WC-10 wt% and wax used as a kind of binder were mixed together by two blade mixer. After injection molding, the debinding process was carried out by two-steps. First, solvent extraction, in which the binder was eliminated by putting the specimen into normal hexane for 24 hrs at $60^{\circ}C$, and subsequently thermal debinding which was conducted at $260^{\circ}C$ and $480^{\circ}C$ for 6 hrs in the mixed gas of $H_2/N_2$, respectively. Meantime, in order to compensate the decarburization due to hydrogen, 1.2~1.8% of carbon was added to ensure the integrity of the phase. Finally, the specimens were sintered in vacuum under different temperatures, and the relative density of 99.8% and hardness of 2100 Hv can be achieved when sintered at $1380^{\circ}C$, even the TRS is lower than the conventional sintering process.

• Analytical Science and Technology
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• v.15 no.4
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• pp.346-359
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• 2002

The brominated flame retardants (BFRs) are one of the unregulated pollutants in Korea, which is recently highlighted the new pollutants of environmental contamination. In this study, the previous research papers related the BFRs were surveyed, and the analytical methods of BFRs were established. The results are followed; The 40 kinds of PBDEs standards were used to establish the analytical methods to perform the experiments of recoveries and detection limits in water and soil. The detection limits of PBDEs using GC/MS represented 5.0~10.0 pg/L for water and 0.5~2.0 ng/g for soil samples. The average recoveries of water samples were 89~98% with ethylacetate, n-hexane and dichloromethane, and 89~103% in combined solvent with n-hexane and acetone. In soxhlet extraction, the higher recoveries obtained the acetone:n-hexane(1:1) comparing with acetone:dichloromethane(1:1).

• Journal of The Korean Society of Inherited Metabolic disease
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• v.11 no.1
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• pp.52-73
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• 2011

Since we have started organic acid analysis on Jul. 1997, we have been collecting data about organic acidemias in Korea. The data presented here is our 3 years experience in organic acid analysis. We have collected 712 samples from major university hospitals all over the Korea, large enough for relatively accurate incidence of organic acid disorders. We are using solvent extraction method with ethylacetate, MSTFA for derivatization and quantitation of 83 organic acids simultaneously. Out of 712 patients sample, 498 patients sample (70%) showed no evidence of organic acid abnormalities. Out of 214 remaining samples we have found very diverse disorders such as methylmalonic aciduria(6), propionic aciduria (10), biotinidase deficiency (6), maple syrup urine disease (3), isovaleric aciduria (4), tyrosinemia type II (4), tyrosinemia type IV (1), glutaric aciduria type I (1), glutaric aciduria type II (22), 3-methylglutaconic aciduria type I (3), 3-methylglutaconic aciduria type III (7), HMG-CoA lyase deficiency (1), hyperglyceroluria (2), cytosolic 3-ketothiolase deficiency (55), mitochondrial 3-ketothiolase deficiency (3), 3-hydroxyisobutyric aciduria (2), L-2-hydroxyglutaric aciduria (2), fumaric aciduria (2), lactic aciduria with combined elevation of pyruvate (most likely PDHC deficiency) (28), lactic aciduria without combined elevation of pyruvate (most likely mitochondrial respiratory chain disorders) (35), SCAD deficiency (3), MCAD deficiency (1), 3-methylcrotonylglycineuria (1), orotic aciduria (most likely urea cycle disorders) (7) and 2-methylbranched chain acyl-CoA dehydrogenase deficiency (1). In conclusion, though the incidence of indivisual organic acidemia is low, the incidence of overall organic acidemia is relatively high in Korea. Most of the patients showed some signs of neurological dysfunction. In other words, organic acid analysis should be included in the diagnostic work up of all neurological dysfunctions.