• Bulletin of the Korean Chemical Society
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• v.21 no.11
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• pp.1101-1105
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• 2000

A simultaneous determination method of BTEX (benzene, toluene, ethylbenzene, o,m.p-xylene) and TPH (kerosene, diesel, jet fuel and bunker C) in soil with gas chromatography/flame ionization detection (GC-FID) was described. The effects of extracti on method, extraction solvent, solvent volume and extraction time on the extraction performance were studied. A sonication method was simpler and more efficient than Soxhlet or shaking methods. Sonication with 10 mL of acetone/methylene chloride (1 : 1, v/v) for 10 min was found to be optimal extraction conditions for 20 g of soil. Peak shapes and quantification of BTEX and TPH were excellent, with linear calibration curves over a wide range of 1-500 mg/L for BTEX and 10-5000 mg/L for TPH. Good reproducibilities by sonication were obtained, with the RSD values below 10%. By using about 20 g of soil, detection limits were 0.8 mg/L for BTEX and 10 mg/L for TPH. The advantages of this procedure are the use of simple and common equipment, reduced volumes of organic solvents, rapid extraction periods of less than 20 min, and simultaneous analysis of volatile and semivolatile compounds.

• 보존과학연구
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• s.29
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• pp.137-148
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• 2008

Analyses of ancient DNA (aDNA) from archaeological and historical skeletal material are characterized by low quality. Many soil contaminants such as humic acid, fulvic acid, and bone collagen are often co-extracted with aDNA and inhibit amplification by polymerase chain reaction (PCR). In this study, we compared with two methods of DNA extraction by phenolchloroform extraction and silica-bead extraction. In addition, we applied new protocol, ultra sonication based silica-bead extraction method to extract aDNA from some ancient human skeletal remains. This method was more effective by both mitochondrial DNA (mtDNA) and amelogenin gene amplification.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.496-503
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• 2021

Background: Considering the expenses of and difficulties in arsenic speciation by high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS), alternative measurement methods should be useful, especially for large-scale research and projects. Objectives: A measurement method was developed for arsenic speciation using HPLC-atomic fluorescence spectrometry (HPLC-AFS) as an alternative to HPLC-ICP-MS. Methods: Total arsenic and toxic arsenic species in some seafoods were determined by atomic absorption spectrometry coupled with hydride vapor generation (AAS-HVG) and HPLC-AFS, respectively. Recovery rate of arsenic species in seafood was evaluated by ultra sonication, microwave and enzyme (pepsin) for the optimal extraction method. Results: Limits of detection of HPLC-AFS for As³⁺, dimethylarsinate (DMA), monomethylarsonate (MMA) and As⁵⁺ were 0.39, 0.53, 0.60 and 0.64 ㎍/L, respectively. The average accuracy ranged from 97.5 to 108.7%, and the coefficient of variation was in the range of 1.2~16.7%. As³⁺, DMA, MMA and As⁵⁺ were detected in kelp, the sum of toxic arsenic in kelp was 40.4 mg/kg. As³⁺, DMA, MMA and As⁵⁺ were not detected in shrimp and squid, but total arsenic (iAS and oAS) content in shrimp and squid analyzed by AAS-HVG were 18.1 and 24.7 mg/kg, respectively. Conclusions: HPLC-AFS was recommendable for the quantitative analysis method of arsenic species. As toxic arsenic species are detected in seaweeds, further researches are needed for the contribution degree of seafood in arsenic exposure.

• Journal of the Korean Chemical Society
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• v.60 no.6
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• pp.452-456
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• 2016

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.504-510
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• 2015

This study was carried out to investigate the antioxidant effects of different parts (stems, leaves, and seeds) of the black raspberry for utilization as food materials. Different parts of the black raspberry were subjected to extraction via ultra-sonication extraction methods using water and ethanol at various concentrations (25, 50, 75, and 100%). Antioxidant capability of the extracts were determined by amounts of phenolic compounds, with flavonoid contents, radical scavenging activity, and reducing power. Irrespectively of ethanol concentration, extracts of stem showed the highest total phenolic compounds and antioxidant activities among different parts of black raspberry. The total phenolic compounds extracted from the black raspberry stem using 25 and 50% ethanol showed $348.21{\pm}5.40$ and $343.39{\pm}5.94mg/g$, respectively. Fifty percent ethanol extracts of the black raspberry stem showed the highest DPPH ($EC_{50}$ value: $60.89{\mu}g/mL$) and ABTS radical scavenging activities ($EC_{50}$ value: $82.57{\mu}g/mL$). Further, 25% ethanol extacts of the black raspberry stem ($0.263{\pm}0.004$) was found to have the highest reducing power. The highest antioxidant activity of black raspberry stem indicates that black raspberry stem may be useful source for functional food.