• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.171-174
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• 2001

Solid phase micro-extraction (SPME), a solvent-free, rapid and inexpensive method for the extraction of organic compounds from aqueous sample matrices, was evaluated for determination of the 120 pesticides in vegetables such as crown daisy, perilla leaf, leafy lettuce and to mato. The analysis conditions were chosen for the SPME method: 15 min of immersion of the PDMS fiber in 10 ml of the solution with stirring at 1,000 rpm. The recovery tests were carried out in triplicate. The range of recoveries was 0-142% for organochlorine pesticides and $4.9\sim200\%$ for organophosphorus pesticides. The recoveries were very low in the pesticide groups with low solubility in water. The recoveries became lower in proportion to the interference materials in vegetables. The recovery in tomato was relatively higher than that in perilla Ie af and crown daisy. The recovery values obtained by SPE and SPME were compared. In leaf y lettuce, recovery obtained by SPE method ranged from $58.1\%\;to\;136.1\%$ and recovery by SPME ranged from $9.6\%\;to\;176.3\%$ In organophosphorus pesticides. The recovery in SPME method was satisfactory with $136\%$ for ethoprophos, $119\%$ for methidathion and $113\%$ for diazinon. Meanwhile, recovery of EPN, phenthoate and 2,4-DDT revealed relatively low value of $38\%,\;41\%\;and\;3.4\%,$ respectively. However, most of pesticides applied to SPME method sho wed constant recovery and precision. From these results, it can be concluded that solid phase micro-extraction might be an appropriate method for the screening test of pesticides in vegetables.

• Journal of Applied Biological Chemistry
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• v.54 no.4
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• pp.290-295
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• 2011

This study was carried out to investigate the quality of soil, irrigation water, and status of agrochemicals application in relation to good agriculture practices system in the major cultivation area of Disocorea batatas. The concentrations of heavy metals as Cd, Pb, Cu, and Zn in soils and irrigation waters were lower than those of standard level for Environmental Conservation Act of Soil and Water in Korea. The dominant weed have been appeared Digitaria sanguinalis and Portulaca oleraceamite. The dominant insect pests and plant pathogens have been appeared aphid and anthracnose. Average yearly application of pesticide was 2 to 4 times for herbicide and 4 to 6 times for plant pathogens and insect pests. In order to safety production of medicinal crops could be achieved by proper cultivation management such as minimum application of agro-chemicals, effective use of by-product fertilizer, and technology development of organic farming.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.151-158
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• 2000

Considerable interest has been shown in recent years towards utilizing $TiO_2$ particles as a photocatalyst in the degradation of harmful organic contaminants. In this study, photocatalytic degradation of diazinon which is extensively used as a pesticide in the agriculture field, has been investigated with UV-illuminated $TiO_2$ weight, UV wavelength, pH of the solution. Photodegradation rate increased with decreasing initial concentration of diazinon and with increasing pH of the solution. Photodegradation rate increased with increasing $TiO_2$ weight, but was nearly the same at $TiO_2$ weight of 1g/$\ell$, 2 g/$\ell$, i.e., for initial diazinon concentratin of 5 mg/$\ell$. UV wavelength affecting on the degradation rate of diazinon decreased in the order of 254 nm>312 nm> 365 nm. For $TiO_2$ weight of 1 g/$\ell$and initial diazinon concentration of 5 mg/$\ell$, the photodegradation removal of diazinon was 100% after 130 min in the case of 254 nm, but 95% in the case of 312 nm, and 84% in the case of 365nm, after 180 min. The photodegradation of diazinon followed a first order or a pseudo - first order reaction rate. For initial diazinon concentration of 5 mg/$\ell$, the rate constants(k) in UV and $TiO_2$(1 g/$\ell$)/UV system were $0.006 min^{-1} and 0.0252 min^{-1} at 254 nm, 0.0055 min^{-1} and 0.0104 min^{-1} at 312 nm, and 0.004 min^{-1}$ at 365 nm respectively.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.239-246
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• 2010

Aphids are one of the major pests in agricultural crops. A number of synthetic pesticides have been used for control of aphids in agriculture, but increasing public concerns over their adverse effects on the environment have required more environmentally-friendly methods for pest management. In this study, we examined plant oil formulations for the control of green peach aphid (Myzus persicae). Oil formulations were prepared by hydrolyzing the plant oils in ethanolic KOH solution and diluted at the rate of 1:500 for aphid control. The oil formulations showed aphid mortalities ranging from 24.44 to 43.33% in vitro. Significantly increased aphid mortalities were observed by the treatment of oil formulations combined with low-dosed imidacloprid. No significant difference in the aphid mortality was observed between the oil formulations. Mass spectrometry analyses of aphids treated with the low dosedimidacloprid plus the plant oil formulations detected similar concentrations of imidacloprid between the treatments. In field trial bioassays against aphids, significantly decreased aphid population were observed in the pepper plants treated with soybean oil formulation combined with the low-dosed imidacloprid, while aphid population dramatically increased in the pepper plants treated with the low-dosed imidacloprid alone. These results suggested that the plant oil formulations can be used as an environmentally-friendly method for enhancing the insecticidal effectiveness, which may play a role in reducing the use of synthetic pesticide in agriculture.

• Korean Journal of Environmental Agriculture
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• v.1 no.1
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• pp.65-70
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• 1982

This experiment was conducted to see the effect of repeated application of IBP granular formulation(17%, 0,0-diisopropyl-S-benzyl thiophosphate) on the biodegradation of IBP and diazinon〔0,0-diethyl 0-(2-isopropyl-4-methyl-5-pyrimidinyl) phosphorothioate〕 in silt loam soil with 2.1% organic matter under flooded condition. The persistence of IBP in the soil was shortened by increasing the frequencies of application of the chemical. Enhanced degradation ability in the soil caused by repeated application of IBP was prolonged about 53 days, while the ability did not influence diazinon persistence in the soil. The half-lives of IBP in sterilized soil autoclaved at $121^{\circ}C$ for 30 minutes were about 3 times longer than those in viable soil, suggesting that microbial process was a major factor for IBP degradation in the soil. The total colony number of soil microbes showed little difference between the soils with and without repeated application of IBP. A possible concern of specific soil microorganisms on the pesticide degradation in soil was discussed.

• Journal of the Korean Dietetic Association
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• v.12 no.4
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• pp.329-341
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• 2006

The purposes of the study were to examine food purchasing management practices and to assess dietitians' awareness on food quality standards, use of food purchasing guidelines(food quality guidelines, supplier selection criteria), and organizational collaboration related to purchasing at school food service. A total of 400 dietitians working at elementary schools in Kyunggi Province were surveyed and 247 responses were returned. Excluding responses with significant missing data, 240 responses(60%) were used for data analysis. Compared to the previous reports, competitive bidding and shorter contract periods were preferred for purchasing food supplies. A dietitian, school staff, and food service staff participated in receiving and inspection together at 58.4% of the schools. An average score of the dietitians' awareness on the food quality standards was 3.28 based on a 5-point scale(1:strongly disagree, 5:strongly agree). Their awareness scores for the quality standards related to the genetically modified organism foods, organic foods, and pesticide residues were the lowest. The awareness scores increased significantly with their age(p<.001). In general, the food purchasing guidelines were used well at the schools ; the usage levels of the food quality guidelines and supplier selection criteria were significantly different by length of operation(p<.05) and dietitians' age(p<.05), respectively. The dietitians' perception score of the organizational collaboration related to purchasing was rated 3.46 and differed significantly by dietitians' educational background(p<.05). For improving food procurement management, standardized food quality and purchasing criteria need to be developed. As the demands on high quality food supplies increase for school food service, the dietitians should improve their knowledges on the food quality standards and implement effective and creative purchasing methods.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.97-102
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• 2000

In order to use Metarhizizmn~ anisopliae as a biological pesticide, effect of envrionmental factors on nlycelial growth, spore formation, and extracellular enzyme activity in culture broth of M. anisopliae DGUM 35001 was determined. Optimal temperature was 26^{\circ}C.$ and optimal pH ranged from 5 to 9. Among the complex media tested, MCM and SDPY media were the most favorable for mycelial growth. When Czapek-Dox agar was used as a mnimal medium, glucose and sucrose among the saccharides were very excellent source of carbohydrate. Among the biopolyners tested. chitin was the most favorable source for mycelial growth and produced high aerial inycelia. Urea and ammonium phosphate as an inorganic nitrogen source and bacto-peptone and soytone as an organic nitrogen source enhanced the mycelial growth When serine as a source of amino acid was supplemented, excellent mycelial growth was shown. Large amount of spores could be obtained from the aerial mycelia of starch medium. When the culture broth was filtrated and then the concentrate with ammonium sulfate was used as a crnde enzyme solution, high enzyme activities of amylase and protease were shown. However, lipase and chitinase activities were comparatively low.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.112-112
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• 2022

This study aims to confirm the possibility of using the invasive alien plants in Jeju as a functional biomaterial. To achieve this purpose, 70% ethanol extract and solvent fractions were prepared for five invasive alien plants (Hypochaeris radicata, Rumex acetosella, Humulus japonicus Siebold & Zucc., Solanum viarum, Lactuca scariolar) and their antioxidant, antibacterial anti-inflammatory and anti-obesity effects were investigated. The DPPH radical scavenging activity of ethanol extract from invasive alien plants was shown in the order of Rumex acetosella > Hypochaeris radicata > Humulus japonicus. Antimicrobial activity of ethanol extract against food poisoning bacteria (4 species) and oral cavity-induced microorganisms (6 species) was measured. As a result, the extract of Humulus japonicus showed high antibacterial effects against food poisoning bacteria (E. coli, V. parahaemolyticus) and oral microbes (L. casei, S. epidermidis, E. faecalis). In LPS-induced RAW 264.7 cells, the anti-inflammatory effect of ethanol extract from invasive alien plants was investigated. As a result, the NO production inhibition activity was highest in the Rumex acetosella and the Humulus japonicus Siebold & Zucc. ethanol extract, and the NO production inhibition activity was concentration-dependent. In addition, the Rumex acetosella and the Humulus japonicus Siebold & Zucc. ethanol extract showed a concentration-dependent inhibitory effect on cytokine (IL-6) production. These extracts also showed inhibitory activity of COX-2, an inflammatory protein. This suggests that NO production inhibition activity by the extract of invasive alien plants is the result of inhibition of iNOS and COX-2 expression. Currently, organic solvent fractions of crude extract are manufactured and the investigation of active ingredients is continuing along with evaluation of biological activity such as anti-inflammatory. These results are expected to be a major data for the study on the separation and utilization of active ingredients with antioxidant, antibacterial and anti-inflammatory effects using foreign plant crude extract and solvent fractions, and are highly likely to be applied to the development of functional food and cosmetics materials.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.335-342
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• 2013

Sophorae radix extract (SRE) has been registered as an environment-friendly organic material that is widely used in the cultivation of crops in Korea. Matrine, the active ingredient in SRE, was reported as a toxic substance in the nervous system in mice. However, no information is available on its toxic effects in other organisms. Therefore, antimutagenicity and two kinds of genotoxicity tests (bacterial reverse mutation and chromosome aberration test) of two samples of SRE were investigated in this study. Antimutagenicity test was experimented by using bacterial reverse mutation test. In the reverse mutation test, Salmonella Typhimurim TA98, TA1535 and TA1537 were used to evaluate the mutagenic potential of SRE. Bacterial reverse mutation test was also performed on positive and negative control groups in the presence of the metabolic activation system (with S-9 mix) and metabolic non-activation system (without S-9 mix). In the chromosome aberration test, Chinese hamster lung cells were exposed to SRE for 6 or 24 hours without S-9 mix, or for 6 hours with S-9 mix. Negative and positive control groups were experimented for chromosome aberration test. As a result, the number of mutated colonies induced by 4-NQO were reduced by SRE treatment in all strains, indicating that SRE may have antimutagenic effects. Reverse mutation was not shown at all concentrations of SRE, regardless of application of the metabolic activation system. In the chromosomal aberration test, one of the SRE sample gave a suspicious positive result at 250 ${\mu}g/ml$ in the presence of S-9 mix. For the more adequate evaluation of the genotoxic potential of SRE samples, other in vivo genotoxicity study is needed.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.211-216
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• 2017

BACKGROUND:This study was conducted to investigate residual organochlorine pesticides (ROCPs) in agricultural soils and crops. Agricultural soil samples and crop samples were collected from 93 cities and counties. METHODS AND RESULTS: Extraction and clean-up for the quantitative analysis of ROCPs were conducted by the modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Recovery and limit of detection (LOD) of ROCPs in agriculturalsoils and crops were 76.5-103.0 and 75.2-93.2%, 0.01-0.08 and $0.10-0.15{\mu}g/kg$, respectively. Detected ROCPs in agricultural soils were ${\alpha}$-endosulfan, ${\beta}$-endosulfan, and endosulfan sulfate, the residue were 2.0-12.0, 1.2-53.1, and $2.2-329.8{\mu}g/kg$, respectively. But these pesticides in all green perilla leaf and green pepper samples were not detected. CONCLUSION: These results showed that ROCPs residues in agricultural soils were not as high as crop safety threatening.