• Journal of the Korean Chemical Society
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• v.57 no.1
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• pp.40-51
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• 2013

In order to develop a quantitation method for Perfluorooctanesulfonic acid(PFOS) contained in plastics that are mainly used in electric and electronic equipment, this study consisted of conducting method validations with LDPE samples using soxhlet solvent extraction and LC/MS. As a result, the limits of detection and quantitation (LOD, LOQ) were $2.58{\mu}g/L$ and $7.82{\mu}g/L$, respectively. Additionally, the recovery was 96-102%. For the correlation coefficient of LC/MS, the $r^2$ value was 0.9992 in the concentration range of $7.82-100{\mu}g/L$, which confirmed its linearity. Furthermore, for the standardization of the analysis method for PFOS in electric and electronic equipment to correspond to EU environmental regulations, we conducted a proficiency test with a number of domestic and international testing laboratories. Three of the ten testing laboratories that participated in the proficiency test submitted outliers. Accordingly, we examined the cause of the outliers using the $^{19}F$ NMR, finding that the main cause was an error in the processing of the results for isomers in PFOS that existed in standard solutions and samples.

• Food Science and Preservation
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• v.10 no.3
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• pp.370-375
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• 2003

To obtain the oil sesame, walnut, whole wheat, and rice bran were extracted for 1, 3, or 6 hr by a shanking water bath(35$^{\circ}C$ and 100 rpm), and by soxhlet extractor(80$^{\circ}C$) for 1, 3 or 6 hr, respectively. The highest yield of extracted oil was obtained from the walnut(63.07％ weight) and the whole wheat showed the lowest extraction yield of oil(1.13％ weight). Major fatty acids from the extracted oils were linoleic, oleic, and palmitic acid. The maximum contents of total phytosterol in sesame, walnut, whole wheat, and rice bran were 0.44, 1.57, 2.25, and 2.03(％ weight), respectively. Besides, total tocopherol contents in sesame, walnut, whole wheat, and rice bran were maxima 3.42, 0.16, 2.92, and 0.07(％ weight), respectively. From the extracted oils, structured lipids(SL) were synthesized by the interesterification reaction with conjugated linoleic acid(CLA) in a shanking water bath at 55$^{\circ}C$. When the reactions(1:3 substrate molar ratio, extracted oil:CLA) were conducted for 24 hr, maxima 23.75 mol％ of CLA incorporation was obtained from walnut oil and, in other cases, 16.28 - 19.15 mol％ of CLA was found in the produced SL triacylglycerol molecules.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.640-647
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• 2008

Breed differences in adult animals are determined during fetal development. If interventions are to be developed that influence growth of muscle and fat, it is important to know at which time during gestation breed differences appear and are fixed. The objective of this study was to characterize fetal development in cattle of different breeds. Pregnant cows of 4 cattle breeds with different growth impetus and muscularity were slaughtered under normal processing conditions and the fetuses were removed. German Angus, a typical beef cattle; Galloway, a smaller, environmentally resistant beef type; Holstein Friesian, a dairy type; and Belgian Blue, an extreme type for muscle growth were used. Fetuses of each breed were investigated at 3, 6, and 9 mo of gestation. Fetuses were weighed and dissected into carcass, organs, and muscles. Body fat weight was obtained using the Soxhlet extraction method. Fetal weight increased most rapidly in the third trimester of gestation mainly due to the accelerated muscle and fat deposition. The organ weight to body weight (BW) ratios decreased and the muscle and fat weight to BW ratios increased. At 3 mo of gestation, Galloway fetuses had the significantly smallest BW, half-carcass weight, leg weight, organ weight, muscle weight and shortest leg length. In contrast, Holstein fetuses had the significantly greatest BW, liver, kidney, and lung weights and significantly longest leg length among the 4 breeds, but no differences between Holstein Friesian and Belgian Blue were detected in half-carcass and leg weight. Indeed, Belgian Blue fetuses had the significantly greatest half-carcass weight, leg weight, and muscle weight at 9 mo of gestation, and Galloway had a significantly greater body fat to BW ratio than Holstein Friesian and Belgian Blue. These differences were not evident at 3 and 6 mo of gestation. These data show that the profound increase of tissue and organ weights occurred in later gestation in cattle fetuses even though breed differences were evident as early as 3 mo of gestation. Depending on the tissue of interest, impacting fetal growth likely needs to occur early in gestation before the appearance of breed-specific differences.

• Journal of the Korean Chemical Society
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• v.39 no.7
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• pp.513-523
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• 1995

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are the most concerned toxic organic pollutants to human. Because of their extremely high toxicity and uncertain genotoxic potential, their determination in environmental and biological samples is of great interest. Municipal solid waste incinerator facilities have been reported as the major contributors of dioxins and furans to the environment, and their formation from combustion is a universal phenomenon, everywhere. In this study dioxins and furans were analyzed from the bottom ash produced during combustion in an municipal waste incinerator located in Seoul. The EPA method was modified for sample pretreatment: the soxhlet method was used for extraction and clean-up procedures were performed by using silica and basic alumina, excluding active-carbon. The extract was then analyzed by HRGC/HRMS. A general trend of increase in the amounts of 6∼7 chlorine-substituted dioxins and furans was observed. Total dioxins, furans and 2,3,7,8-TCDD were determined as 8.05 ng/g, 4.75 ng/g, and 6.93 pg/g, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.250.1-250.1
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• 2010

최근 석유공급 불안정성과 이산화탄소 배출 규제 움직임에 대응하기 위한 수단으로 바이오연료의 공급이 전세계적으로 증가하고 있다. 이와 같은 바이오디젤의 보급 활성화는 식물성 기름의 가격 상승과 수급 불안정 문제, 그리고 식량자원과의 충돌 문제를 야기하고 있다. 국내 바이오디젤 생산 원료로 사용되는 대두, 유채, 해바라기, 팜 등은 모두 식용시장과 수급 균형을 형성하고 있어 바이오디젤의 생산이 증가하게 되면 식용 오일 시장의 수급균형이 깨져 오일곡물 가격의 변동을 초래하게 될 것이다. 과거에는 수거비용을 들여 폐기하던 폐식용유 마저 이제는 돈을 주고 구입해야하는 실정에 다다랐다. 바이오디젤 생산비의 70~80%를 차지하는 원료유의 부족 현상에 따라 바이오디젤 업계에서는 soapstock, trapped grease, 폐식용유 등의 저급유지 활용 방안을 강구하고 있으며 자트로파와 같은 비식용 작물의 해외플랜테이션도 진행하고 있다. 본 연구에서는 커피찌거기에 남아 있는 오일을 속슬렛추출장치를 이용해 추출하고 전이에스테르화 반응을 수행하여 반응 특성과 커피오일 바이오디젤의 지방산 조성을 알아보고 바이오디젤 원료유로서의 사용가능성에 대해 알아보았다. 석유에테르를 용매로 속슬렛 추출장치를 이용해 추출시 원료대비 약 17%(w/w)의 오일을 추출할 수 있었다. 추출된 오일의 산가는 18.79mgKOH/g으로 매우 높아 직접 전이에스테르화 반응이 불가능하다. 고체 산 촉매 하에서 전처리 반응을 실시하여 유리지방산을 전환 제거한 후 염기촉매를 이용해 전이에스테르화 반응을 진행한 결과 약 80%의 바이오디젤(FAME) 함량을 얻을 수 있었다. 지방산 조성 분석 결과 리놀레익산(Linoleic acid, C18:2), 올레익산(Oleic acid, C18:1), 팔미틱산(Palmitic acid, C16:0)이 대부분을 차지하며 이 중에서도 리놀레익산이 44.17%로 가장 많은 함량을 보였다. 이는 커피찌꺼기 추출 오일이 바이오디젤 원료유로 활용 가능성을 나타내는 결과로, 색소성분 등의 불순물을 효율적으로 제거하여 증류정제 전단계에서의 바이오디젤 순도와 생산 수율을 증대시키기 위한 추가 연구가 필요한 것으로 판단된다.

• Economic and Environmental Geology
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• v.12 no.4
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• pp.207-221
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• 1979

The studied area occupies the southern part of Haenam peninsula located in the southwestern corner of Korea. The stratigraphic sequences of the area are grouped into following three units in ascending order. (1) Late Cretaceous sedimentary rocks of Uhangri Formation which consist of the alternative beds of black shales and tuffaceous sediments, Hwangsan acidic fine grained tuffs and Jindo rhyolite flows. (2) Late Cretaceous biotite granite and acidic porphyries which intruded the Late Cretaceous sedimentary rocks. (3) Tertiary(?) pitchstone. The study purposes to delineate any of geochemical aspects on the deposition of the sequences, the average amounts of organic materials and the effect to the maturation of hydrocarbonization which has been occured by the intrusives. Sixty nine black shale samples were collected from Uhangri Formation in the northern and southern coasts of the peninsula. Organic carbons, total extracted organic matters and hydrocarbons were mainly determined by the Soxhlet extraction method, together with C-H-N elemental analyses. Based on the field and laboratory studies, the following interpretations have been obtained. (1) The paleohydrostatic condition of the sedimentation which took place was relatively calm and stable to delineate a lacustrine environment. (2) The amounts of organic material were more or less constant throughout the period of the deposition of the sediments. (3) The degree of hydrocarbonization of the Uhangri Formation in the northern coast was taken place higher than that in the southern coast due to the differences of thermal effect by the biotite granite which is assumed to be as a heat source in the area. Among the northern coast, some black shales in Uhangri and Mogsam areas which had been under the most moderate temperature environment snow symptomatic oily material, whereas, those in Sinseongri area do not, which were presumably to be intensive thermal alteration by the later acidic porphyries.

• Korean Journal of Medicinal Crop Science
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• v.26 no.1
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• pp.32-41
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• 2018

Background: To obtain useful safflower resources for breeding and research of functional materials, the present study was conducted to determine fatty acid compositions and antioxidant activities of 281 safflower accessions collected from East Asia including South Korea. Methods and Results: Lipid contents and fatty acids compositions were evaluated using soxhlet extraction and gas chromatography, respectively. A antioxidant activities were analyzed using a spectrophotometer. The evaluation range of safflower accessions showed very wide variation. In terms of lipid contents, the China accessions were higher than the collection from other regions, whereas antioxidant activities did not differ among regions. The result of the principal component analysis showed that the first and second principal component cumulatively explained 90.6% of the total variation. In clustering the safflower accessions, the tree showed four major clades. Group II (16 accessions) was high in lipid content, oleic acid and linoleic acid, whereas group III (50 accessions) exhibited higher antioxidant activities than other groups. Conclusions: It was recommended that the China collections be utilized as a useful resource for research on functional oil materials. These results provided valuable information for safflower breeders and researchers of functional food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.158-163
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• 2004

We investigated the usefulness of 2-alkylcyclobutanones as markers for irradiated eggs and egg products by comparing 2-alkylcyclobutanone concentrations in irradiated raw egg yolk, boiled egg yolk, and egg yolk powder. One method of detection radiation-induced 2-alkylcyclobutanones involves extraction fat from irradiated egg samples separating 2-alkylcyclobutanones by florisil column chromatography, and identifying GC/MS. 2-(5'-Tetradecenyl)cyclobutanone of 2-alkylcyclobutanones was high relatively in boiled egg yolk, but 2-dodecylcyclobutanone was high in raw egg yolk and egg yolk Powder. Concentrations of the radiation-induced 2-alkylcyclobutanones increased linearly with the irradiation dose. The radiation-induced 2-alkylcyclobutanones from egg samples at 0.5 kGy over and not detected at the non-irradiated samples. Therefore, these compounds could be used as marker of Post-irradiation for egg Products.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.85-88
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• 2003

Polycyclic aromatic hydrocarbons (PARs) are an important group of organic contaminants present in sewage sludge, due to their persistence, toxic, bioaccumulative and long range transfer. These characters make themselves as Persistent Organic Pollutants(POPs) in Long Range Transboundary Air Pollutions convention(LRT AP) of Europe. A method of the gas chromatographic-mass spectrometric (GC-MS) determination of PARs present in sewage sludge was developed and applied to analyzed samples from five sewerage treatment plants (SWTPs), having different treatment types. PARs were extracted from freeze-dried samples by toluene 16 hours in a soxhlet extraction system. The sludge extracts were cleaned-up by an activated silica gel column chromatography. The sum of the 16 US Environmental Protection Agency PARs sewage sludge samples varied from 2.44 to 4.82 ${\mu}g$/g. Concentration of emission carcinogen PARs(PARcarc), such as Benzo(a)anthracene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, Benzo(a)pyrene, Dibenzo(a, h)anthracene and Indeno(1, 2, 3-cd)pyrene ranged from 0.62 to 1.03 ${\mu}g$/g. The total amount of PAHs emission from sewage sludge in Korea was calculated as a top-down approach. PARs and $\sum$PAHcarc from sewage treatment plants had several pathway each by-products. In the ocean dumping, PAHs and $\sum$PAHcarc emissions were 1155.95 kg/year and 5040.32 kg/year. In recycle, PAHs and $\sum$PAHcarc emissions were 98.36 kg/year and 428.87 kg/year. In the landfill, PAHs and $\sum$PAHcarc emissions were 190.40 kg/year and 830.21 kg/year. In the incineration, PAHs and $\sum$PAHcarc emission were 33.10 kg/year and 830.21 kg/year. (In case of incineration, the whole provisions of PARs and $\sum$PAHcarc contained to flowed in sludge was supposed to be exhausted to environment through exhaust after incineration.)

• 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).