• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.202-208
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• 2009

The dechlorination of endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine-3-oxide) and its metabolite, endosulfan sulfate via reaction with zerovalent iron under various pH conditions was studied using aqueous solution. The reaction products, which were probably produced from endosulfan and endosulfan sulfate by ZVI were identified by GC-MS. The lower the pH of reaction solution, the higher the transformation rate of endosulfan and endosulfan sulfate. The transformation rates of endosulfan and endosulfan sulfate in pH 3.0 by ZVI were 28% and 90% but those of endosulfan and endosulfan sulfate in mixture solution of water/acetone were 65% and 92%, respectively. The pH of reaction solution after ZVI treatment was increased to pH 10. Endosulfan was hydrolyzed at pH 10 but endosulfan sulfate was not hydrolyzed. Two unknown peaks were produced from endosulfan sulfate by treatment of ZVI. As a result of GC-MS analysis, unknown peaks were guessed to be structural isomer substituted hydrogen for chlorine.

• 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.

• Journal of Nutrition and Health
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• v.13 no.1
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• pp.51-58
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• 1980

In order to investigate the level of pesticide residues in the vegetables for Kimchi materials (Chinese cabbage, radish, red pepper, garlic and cucumber), which were produced in Andong district, organochlorine and organophosphur pesticide residues were analyzed using gas chromatography. The results were as follows; 1) In chinese cabbage, radish and some other vegetables harvested in early summer (June), organochlorine and organophosphur pesticide residues were detected in almost all of the samples tested, and a few of them showed a level higher than the organochlor APR(allowable pesticide residues). 2) Heptachlor, the soil insecticide was the most abundantly detected pesticide among the four organochlorine pesticides tested (Dieldrin, Endrin, BHC, Heptachlor) in this study. 3) Somewhat higher concentrations of organochlorine pesticides were detected in all kinds of sample vegetables harvested in late summer than in those harvested in early summer. And the frequency of organochlorine pesticide contamination was also increased, but the frequency of organophosphur pesticide contamination was decreased. 4) In the vegetable harvested in late autumn, level of organochlorine pesticide residues and frequency of contamination were markedly decreased and organophosphur pesticide residues (Diaginon, Malathion, Thiometon, EPN) were rarely detected. 5) The results of this study indicates that to take a lot of vegitables grown in summer was somewhat uncomfortable than those grown in autumn.

• Applied Biological Chemistry
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• v.23 no.1
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• pp.58-63
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• 1980

Present investigation is undertaken to evaluate residues of organochlorine pesticides and PCBs in river sediments and cultivated soils by GLC. Main sampling areas chosen were three industrial estates, Suwon, Iri and Kumi. Samples consist of river sediments and cultivated soils, in Suwon, Iri and Chilgok, which are likely to be accumulated with PCBs from nearby factories. Organochlorine pesticide residues were found in all sediments and soil samples while no PCBs residue was detected in all samples analyzed. The pesticide residues were greatest in the Suwon and least in Chilgok soils. p,p'-DDT and BHC isomers $({\alpha}-,\;and\;{\gamma}-)$ were found in all soil samples. p,p'-DDT, at the range of 0.006-0.840 ppm, was the most abundant residues among organochlorine insecticides.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.266-271
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• 2010

Six insecticides, monocrotophos (24%, Lq), milbemectin (1%, Ec), tebufenpyrad (10%, Ec), propargite (30%, Wp), dicofol (42%, Ec), and fenpropathrin (5%, Ec) were studied for their $LC_{50}s$ to local two-spotted spider mite (TSSM) strains collected at apple orchards in Chungju, Kunwi and Sobo in Korea. Monocrotophos and fenpropathrin were not effective due to resistance development, but milbemectin, tebufenpyrad, dicofol and propargite were effective to TSSM. $LC_{50}$ values to TSSM strains showed the same distribution pattern among apple orchards. However, TSSMs from different apple orchard were clustered into different groups.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.187-197
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• 1984

Samples (river water, tap water, soil, sediment, fish and shellfish) collected in Downstream Area of Nakdong River were analyzed for organochlorine pesticides by G.C. equipped with electron capture detector. Residue levels of organochlorine pesticides in the river water and tap water ranged from less than detection limit (ND) to 56ppt. Total BHC concentration in the river water and tap water were found to increase in summer and decrease in winter. The variation appeared to be related to rain fall. ${\alpha}-BHC\;and\;{\beta}-BHC$ concentration in the soil were ND-3.3ppb and ND-769.7ppb, respectively. ${\alpha}-BHC\;and\;{\beta}-BHC$ concentration in the sediment were ND-2.0ppb and ND-409.9ppb, respectively. Concentration factor of total BHC in the sediment ranged from 83 to 3213. In fish, Carasssus carassius and shellfish, Anodonta woodiana(Lea) the concentration factor of ${\beta}-BHC$ and total BHC were 2,609, 435 and 3,261, 375, respectively.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.207-215
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• 2011

An endosulfan degrading bacterial strain, K-1321, was isolated by endosulfan-enrichment culture from a seaside sediment collected at Dadaepo Beach, Busan, Korea. The strain was identified as a Serratia sp. based on the results of morphological, biochemical and 16S rDNA homology analyses. Serratia sp. K-1321 was able to completely degrade 50 ppm endosulfan in culture media and soil within 6 weeks at $25^{\circ}C$. GC/MS analysis revealed that endosulfan diol was an intermediate of the bacterial endosulfan degradation. Considering the above results, we concluded that Serratia sp. K-1321 utilized endosulfan as a carbon source and metabolized endosulfan via a less toxic pathway, such as the formation of endosulfan diol as an intermediate.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.6
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• pp.475-485
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• 2002

An analytical method was investigated for the meaiiurement of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) concentrations in air samples. Procedures required for column chromatographic clean up. silicagel (stage I) and gel permeation chromatography (stage II), were discussed. Identification and quantification of PCBs and OCPs were performed using a combination of gas chromatography/mass spectrometry/ selected ion monitoring. Recovery tests calculated from six samples are 68∼137% for PCBs and 58∼130% for OCPs except for endrin aldehyde. Instrumental detection limits determined for the PCBs and OCPs varied from 0.05 to 0.18 pg/m3 and from 0.71 to 16.82 pg/㎥, respectively. The method has been applied to the analysis of air samples collected at Ansung city, Kyonggi province, Korea. This method may serve as a screening protocol for the simultaneous determination of PCBs and OCPs in air.

• Korean Journal of Environmental Agriculture
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• v.1 no.2
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• pp.105-115
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• 1982

Environmental samples contaminated with elemental sulfur(waters 22, sediments 20, crucian carps 19) collected from Soho Lake during the period of Sep. 1981 to Apr. 1982 were analyzed for polychlorinated biphenyls(PCBs) and organochlorine insecticides by GLC-ECD. Elemental sulfur was found to interfere in the residue analysis of environmental samples and the sulfur was eliminated, prior to analysis, with copper powder. PCBs residues in Soho lake were temporarily characterized as Aroclor 1254 and were analyzed at minimum detectable quantity of 0.04 ng by derivatizing PCBs to decachlorobiphenyl(DCB). PCBs were positively detected in all samples and its residue levels in waters, sediments, and crucian carps were $0.015{\sim}0.15$ ppb, $0.038{\sim}0.088$ ppm and 0.091 ppm, respectively. The residue levels of PCBs in all samples but sediments at central and outlet site of the lake were higher than those of total p,p'-DDT. The residue levels of PCBs in waters varied with inlets, i.e. those at right inlet site were three times of those at left inlet site. The main source of PCBs residues in the environmental samples of Soho Lake was not evident by present work.