• Title/Summary/Keyword: DDE

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Determination of 25 EDs in Frog and Fish Tissue by GC-MS (SIM)

  • Shin, Ueon-Sang;Shin, Ho-Sang
    • Bulletin of the Korean Chemical Society
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    • v.24 no.4
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    • pp.413-420
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    • 2003
  • A gas chromatography/mass spectrometric assay method was developed for the simultaneous determination of neutral and bacis twenty-five disruptors $(ED_S)$ in frog and fish. Afther homogenization and sonication of 5 g of sample, purification was achieves in one step with a solid phase extraction procedure using silica gelflorisl. Eluton was performed with 50mL of acetone : n-hexane (1 : 9) solution. The eluate was concentrated to approximately 10uL and dissolves with 100 uL of hexane and analyzed by GC-MS (SIM). The peaks had good chromatographic properties and the extraction of these compounds from sample also gave relatively high recoveries with small variatoins. Detection limits were 0.1 ng/g for 4-nitrotoluene, benzophenone, hexachlorobenzene, atrazine, malathion, o,p-DDT, o,p-DDT and permethrin, and 0.2 ng/g for heptachlor epoxide, γ-chlordane, α-chlordane, p,p'-DDE, p,p'-DDD, cypermethrin and fenvalerate, and 0.3 ng/g for trifluralin, metribuzin, alachlor, dieldrin and p,p'-DDT, and 0.5 ng/g for heptachlor, aldrin and parathion, and 0.7 ng/g for endrin, and 0.8 ng/g for nitrofen. The recoveries were between 33 and 109%. The method was used to analyze twenty-five frogs and forty-six fishes fishes samples caught from various regions in Korea. Benzophenone was detected at concentration of up to 17.2 ng/g in frog or fish. Heptachlor, aldrin, γ-chlordane, p,p'-DDE, p,p'-DDD, endrin and o,p-DDD were detected at concentrations of 0.7-12.5 ng/g in frog or fish. Also significant leveles of dieldrin (up to 22.5 ng/g) were observed. The developed method may be valuable to be used to the national monitoring project of EDS in biota samples.

The Electric Breakdown Chatacteristics of Polyimide Thin Films by Self Healing Method (자기절연회복법에 의한 폴리아미드 박막의 절연파괴특성)

  • Kim, Hyeong-Gweon;Lee Eun-Hak;Park, Jong-Kwan
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.36T no.2
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    • pp.1-7
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    • 1999
  • The polymide thin films were fabricated by vapor deposition polymerized method of dry processes and studied the electric breakdown characteristics by self healing method. Polyamic-acid(PAA) thin films prepared by vapor deposition-polymerization (VDP) from PMDA(Pyromellitic dianhydride) and DDE(4,4'-diaminodiphenyl ether) were changed to PI thin films by thermal curing. In the same sample, electric breakdown fields increase with increasing test number, and then saturated over test number of the 25th. When the curing temperatures were 200$^{\circ}C$, 250$^{\circ}C$, 300$^{\circ}C$ and 350$^{\circ}C$, the electric breakdown strengths of PI were 1.21MV/cm, 3.94MV/cm, 4.61MV/cm and 4.55MV/cm at the test number of 40th.

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Organochlorine Insecticide Residues in Cow's Milk Produced in Korea (한국산 우유(牛乳) 중 유기염소계(有機鹽素系) 잔류농약(殘溜農藥)의 검색(檢索))

  • Kim, Yong-Hwa;Lee, Su-Rae
    • Korean Journal of Food Science and Technology
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    • v.12 no.3
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    • pp.141-149
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    • 1980
  • In order to determine the residue levels of organochlorine insecticides in cow's milk, 66 commercial milk samples were collected from markets in major cities of Korea and analyzed for their fat contents and pesticide residue levels. The fat contents were in the range of $2.65{\sim}3.87%$, the average being 3.35%. The average residue levels of organochlorine insecticides on fat basis (whole milk basis in parentheses) were 0.196 ppm (0. 0066 ppm) of ${\alpha}-BHC$, 0.159ppm (0.0055 ppm) of ${\beta}-BHC$, 0.066 ppm (0.0022 ppm) of heptachlor epoxide and 0.042ppm (0.0015 ppm) of DDE. Heptachlor, DDT and drin insecticides were not detected. These residue levels corresponding to $1/10{\sim}1/50$ of tolerance levels adopted in Japan appear to exhibit no adverse effect as yet from the standpoint of food safety.

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Synthesis and Characterization of New Positive Type Photosensitive Poly(amic acid)s (신규 양성형 감광성 폴리암산의 합성 및 특성 연구)

  • Sim Hyun-Bo;Yu Yeong-Im;Yi Mi-Hye
    • Polymer(Korea)
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    • v.30 no.2
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    • pp.162-167
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    • 2006
  • Polyamic acid (PAA) was prepared from cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA) and 4,4'-fiaminodiphenyl ether (DDE). In order to impart a photosensitivity to the PAA, diazonaphthoquinone (DNQ) derivative (DI) was added. However, the addition of the DI was not enough to inhibit the dissolution of the PAA for a aqueous alkal solution. Therefore, we had synthesized poly(amic acid ester)s by an adding 1,2-epoxy-3-phenoxypropane to the PAA. That is, an acidity of the PAA could be controlled by an esterification reaction of 1,2-epoxy-3-phenoxypropane with the PAA. Significant difference of a dissolution rate of the poly(amic acid ester) between an o(posed and unexposed area was observed at an acid content of 60% and less. Resolution of the positively patterned film showed about $25{\mu}m$ at the exposure dose of $200mJ/cm^2$.

Comparative Assessment of Specific Genes of Bacteria and Enzyme over Water Quality Parameters by Quantitative PCR in Uncontrolled Landfill (정량 PCR을 이용한 비위생 매립지의 특정 세균 및 효소 유전자와 수질인자와의 상관관계 평가)

  • Han, Ji-Sun;Sung, Eun-Hae;Park, Hun-Ju;Kim, Chang-Gyun
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.8
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    • pp.895-903
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    • 2007
  • As for the increasing demanding on the development of direct-ecological landfill monitoring methods, it is needed for critically defining the condition of landfills and their influence on the environment, quantifying the amount of enzymes and bacteria mainly concerned with biochemical reaction in the landfills. This study was thus conducted to understand the fates of contaminants in association with groundwater quality parameters. For the study, groundwater was seasonally sampled from four closed unsanitary landfills(i.e. Cheonan(C), Wonju(W), Nonsan(N), Pyeongtaek(P) sites) in which microbial diversity was simultaneously obtained by 16S rDNA methods. Subsequently, a number of primer sets were prepared for quantifying the specific gene of representative bacteria and the gene of encoding enzymes dominantly found in the landfills. The relationship between water quality parameters and gene quantification were compared based on correlation factors. Correlation between DSR(Sulfate reduction bacteria) gene and BOD(Biochemical Oxygen Demand) was greater than 0.8 while NSR(Nitrification bacteria-Nitrospira sp.) gene and nitrate were related more than 0.9. A stabilization indicator(BOD/COD) and MTOT(Methane Oxidation bacteria), MCR(Methyl coenzyme M reductase), Dde(Dechloromonas denitrificans) genes were correlated over 0.8, but ferric iron and Fli(Ferribacterium limineticm) gene were at the lowest of 0.7. For MTOT, it was at the highest related at 100% over BOD/COD. In addition, anaerobic genes(i.e., nirS-Nitrite reductase, MCR. Dde, DSR) and DO were also related more than 0.8, which showing anaerobic reactions generally dependant upon DO. As demonstrated in the study, molecular biological investigation and water quality parameters are highly co-linked, so that quantitative real-time PCR could be cooperatively used for assessing landfill stabilization in association with the conventional monitoring parameters.

Dual - Drive & - Emission Panel

  • Miyashita, Takuya;Naka, Shigeki;Okada, Hiroyuki;Onnagawa, Hiroyoshi
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.707-710
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    • 2004
  • We have proposed on dual-drive & -emission (DDE) panel based on organic light-emitting diodes (OLEDs). The device is composed on independent operation of two OLED structures with two transparent electrodes for data signals and an intermediate reflective electrode for common scan signal. Typical device structure is ITO / organic electroluminescent layer (1) /intermediate reflective electrode / organic electroluminescent layer (2) /transparent electrode. Symmetric bright emission could be obtained by applying AlNd as the intermediate reflective electrode and $MoO_3$ as a hole injection layer for upper device structure. The proposed panel is useful for emissive face-to-face panel exhibited for different images.

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A Study of The Photosensitive Characteristic and Fabrication of Polyimide Thin Film by Dry Processing (건식법을 이용한 폴리이미드 박막의 제조 및 광특성)

  • Lee, Boong-Joo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.1
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    • pp.139-141
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    • 2007
  • Thin films of polyimide (Pl) were fabricated by a vapor deposition polymerization method (VDPM) and studied for the photosensitive characteristic. Polyamic acid (PAA) thin films fabricated by vapor deposition polymerization (VDP) from 6FDA and 4-4' DDE were converted to PI thin films by thermal curing. From AFM and Ellipsometer experimental, the films thickness was decreased and the reflectance was increased as the curing temperature was increased. Those results implies that thin film is uniform. From UV-Vis spectra, PI thin films showed high absorbance in 225 $\sim$ 260 [nm] region.

Codon 311 Polymorphism of Paraoxonase-2 Gene and Hypertension in Korean (한국인에서 Paraoxonase-2 유전자의 Codon 311 다형성에 관한 연구)

  • Jang Dai Ho;Kang Byung Yong;Lee Kang Oh
    • Environmental Analysis Health and Toxicology
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    • v.19 no.2
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    • pp.135-140
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    • 2004
  • 고혈압에서 지질대사 이상은 빈번히 나타나는 현상으로, 지질대사 이상에 관여하는 유전자들은 고혈압의 발병원인을 규명하기 위한 후보 유전자로 인식되어 왔다. 이에 본 연구에서는 paraoxonase 2(PON2) 유전자에 존재하는 Cys311Ser다형성을 유전자 표지로 이용하여 한국인 집단에서 이 유전자 표지가 고혈압과 관련성이 있는 지를 조사하고자 하였다. 연구 대상은 총 195명으로, 이들 중에서 82명은 고혈압 환자 군이었고, 나머지 113명은 정상 혈압 군이었다. PON2 유전자의 Cys311Ser 다형성을 분석하기 위해서 중합효소 연쇄반응과 제한 효소인 Dde Ⅰ처리를 수행하여 유전자형을 결정하였다. 연구 결과, Cys/Ser이 형접합체를 갖는 사람들이 고혈압군에서 유의하게 높은 빈도로 나타났으며(P<0.05),다른 신체 계측치 및 혈청내 지질 농도와는 유의한 관련성을 나타내지 않았다. 본 연구에서 관찰된 이러한 관련성이 기능적인 연관인지 혹은 연관불평형에 의한 결과인지에 대해서는 보다 더 많은 연구 대상을 이용한 추시를 통해 밝혀질 수 있을 것으로 생각된다.

Variation of Atmospheric Concentrations of Organochlorine Pesticides (OCPs) and Polychlorinated Biphenyls (PCBs) at Different Height (대기 중 유기염소계 살충제(OCPs)와 PCBs의 높이별 농도 변화)

  • Chun, Man-Young;Choi, Min-Kyu;Yeo, Hyun-Gu
    • Environmental Analysis Health and Toxicology
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    • v.23 no.3
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    • pp.201-211
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    • 2008
  • This study was performed to find the atmospheric concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) at four different heights (l0, 50, 150 and 1,500 cm) using low volume polyurethane foam (PUF) plug air sampler in semi-rural area. ${\alpha}-/{\beta}-/{\gamma}-HCH$ with low molecular weights and Koa (octanol-air partitioning coefficient) in OCPs were similarly high concentrations at all heights, but the other OCPs (p,p'-DDE, p,p'-DDD, p,p'-DDT, Heptachlor epoxide, ${\gamma}$-CHL, ${\alpha}$-CHL, Trans-nonachlor) with high molecular weights and Koa decreased with increasing heights. However, the concentrations of PCBs increased with increasing height.

A study on the electric breakdown of polyimide thin film fabricated by vapor deposition polymerization (진공증착중합법에 의해 제조된 폴리이미드박막의 절연파괴특성)

  • 이붕주;김형권;김종석;한상옥;박강식;김영봉;이덕출
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.293-296
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    • 1997
  • The experimental system used for vapor deposition polymerization (VDP) from PMDA (Pyromellitic dianhydride) and DDE (4, 4-diaminodiphenyl ether) were changed to PI (polyimide) thin films by thermal curing. The curing temperatures were 20$0^{\circ}C$, 25$0^{\circ}C$, 30$0^{\circ}C$, 35$0^{\circ}C$. When test number was 40, the electric breakdown strengths of PI were 1.21MV/cm, 3.94MV/cm, 4.61MV/cm, 4.55MV/cm according to curing temperatures.

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