• Korean Journal of Food Science and Technology
• /
• v.28 no.3
• /
• pp.475-481
• /
• 1996

A simple, fast, inexpensive method hal been developed to extract organochlorine pesticide spiked in fish tissues by supercritical carbon dioxide. Following static supercritical fluid extraction (SFE), pesticides are collected by rapidly depressurizing the carbon dioxide effluent through a 0.79 mm i.d. metering valve into a capped screw-top tube. Percent recovers of standard organochlorine pesticides mixture (SOPM) increased with the decrease of the extraction temperature at 103 bar. Maximum average percent recovery of SOPM was 98% at $40^{\circ}C/172\;bar$ Average recoveries of SOPM spiked in Pacific cod, flatfish and common squid were 85,74,and 83% respectively at $40^{\circ}C/172\;bar$ Application of supercritical carbon dioxide ectraction offers and attractive alternative to the use of organic solvents for extraction of organochlorine pesticides from fish tissues.

• The Korean Journal of Pesticide Science
• /
• v.15 no.4
• /
• pp.374-382
• /
• 2011

We investigated the mutagenicity of methiozolin, newly developed herbicide, in vitro reverse mutation test using Salmonella typhimurium and Escherichia coli, chromosome aberration test using chinese hamster lung (CHL) cells and in vivo micronucleus test of mice. In the reverse mutation test, the methiozolin did not induce mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, Escherichia coli WP2uvrA with and without metabolic activation at $5,000{\mu}g$/plate. In the chromosome aberration test, the results showed no incidence of increased structural and numerical chromosome abberrations at any doses tested (80, 40, $20{\mu}g$/mL). In micronucleous test, the ratio of micronuclei was measured in polychromatic erythrocytes with treated methiozolin for ICR mice. No incidence of increased micronuclei were observed in polychromatic erythrocytes (1,500, 1,000, 500 mg/kg). Based on these results, we concluded that methiozolin has no mutagenic toxicity in vitro and in vivo systems.

• Korean journal of applied entomology
• /
• v.55 no.4
• /
• pp.319-327
• /
• 2016

Chemical pesticides have been used to control persimmon pests, however the overuse of the pesticides caused insect resistance, followed by failure in pest management and residual problems. Herein we investigate the potential of eco-friendly organic pesticides (EFOP) on the control persimmon pests, Stathmopoda masinissa (persimmon fruit moth) and Riptortus pedestris (bean bug). Ten commercially available plant-derived organic pesticides and one microbial pesticide were sprayed on the target insects in laboratory conditions. The chemical pesticide, buprofezin+dinotefuran wettable powder served as a positive control. In the first bioassay against persimmon fruit moth, alternatively Plutella xylostella larvae were used due to the lack of persimmon fruit moth population from fields, and three organic pesticides showed high control efficacy, such as pyroligneous liquor (EFOP-1), the mixture of Chinese scholar tree extract, goosefoot and subtripinnata extracts (EFOP-2) and Bacillus thuringiensis subsp. aizawai NT0423 (EFOP-11). When the three selected organic pesticides were treated on the persimmon fruit moths, the EFOP-2 treatment showed the highest control efficacy: 27.7% (5 days), 13.3% (7 days) and 6.7% (10 days) of survival rates. In the bioassay against bean bugs, the mixture of Chinese scholar tree, goosefoot and subtripinnata extracts (EFOP-2 and EFOP-9) and the extracts of sophora and derris (EFOP-10) showed high control efficacy, particularly the highest in the treatment of EFOP-2: 20.0% (5 days) and 16.7% (10 days) of survival rates. These results suggest that the mixture of Chinese scholar tree, goosefoot and subtripinnata extracts (EFOP-2) has high and multiple potential in the management of the persimmon pests.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.2
• /
• pp.160-165
• /
• 2011

BACKGROUND: This study carried out to fate of pesticide and investigate worker exposure of pesticide in air after applying granular type pesticide formulation on soil in greenhouse for preventing farmer's pesticide intoxication. METHODS AND RESULTS: The recovery of pesticide, cadusafos, ethoprophos and probenazole on absorbent in air were ranged 80.9~121.1% in charcoal and 90.6~99.0% in XAD-4, respectively. Emission rate of in lysimeter was higher 3~5 times than that of pesticides from topsoil not added water at $35^{\circ}C$ plot after applying a mixture of granular formulation and soil. The ethoprophos concentration in air, 50 cm high from soil surface at greenhouse, was reached the highest 186.4 ${\mu}g/m^3$ within 13 hours and were ranged 17.8~186.4 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 150 g a.i./245 $m^2$. The cadusafos concentration in air at greenhouse was reached the highest 37.3 ${\mu}g/m^3$ within 39 hours and were ranged 10.0~37.3 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 180 g a.i./245 $m^2$. The probenazole concentration in air at greenhouse was reached the highest 1.45 ${\mu}g/m^3$ within 37 hours and were ranged 0.23~1.45 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 144 g a.i./245 $m^2$. CONCLUSION(s): The result of the reentry interval study demonstrated that reentry intervals for ethoprophos and cadusafos are longer than 48 hours.

• The Korean Journal of Pesticide Science
• /
• v.17 no.3
• /
• pp.213-219
• /
• 2013

This study focused on the promotion of the insecticidal activity of eco-friendly insecticidal materials against four major insect pest in the organic Chinese cabbage cultivation area. Among insecticidal materials mixture, BT+Matrine+Neem against leaf beetle larva, Phaedon brassicae, showed the highest 94.1% at 0.05% which is the lowest concentration of three treated concentrations. The insecticidal activity of Matrine, Neem, and BT alone (0.1%, w/v) or the mixtures (0.05%, w/v) against Cabbage worm larva, Artogeria rapae, was investigated by leaf disc spray method. The insecticidal efficacy of the mixtures of two or three eco-friendly materials was higher than the single treatment of each material with 94.3%, 100% and 100%. Control efficacy of 0.3% COY+0.05% (95.3%) against the green peach aphid, Myzus persicae was higher than that of 0.3% COY+0.05% Neem (90.2%) and lasted for more than 21 days after one time treatment. At 35 days after treatment, the effect of 0.05% BT+0.05% Matrine and 0.05% BT+0.05% Matrine+0.05% Neem treatments against diamondback moth showed very high insecticidal activity with more than 90% of control value. Therefore, BT, Neem, and Matrine where are properly treated could be effective eco-friendly materials for controlling major insect pests in an organic Chinese cabbage field.

• The Korean Journal of Pesticide Science
• /
• v.15 no.3
• /
• pp.323-328
• /
• 2011

Control efficacies of mixing of powdery mildew biofungicides with other control agents against major or fungal diseases of cucumber were investigated. Control efficacies against cucumber powdery mildew were quite different according to the kinds of biofungicides applied but those of powdery mildew biofungicides were increased by mixing application of two biofungicides. More than 80% of control efficacies on powdery and downy mildews of cucumber were obtained by mixing application of a powdery mildew biofungicide Bacillus subtilis KB-401 and a downy mildew chemical fungicide dimethomorph. Similarly, control efficacies on powdery and downy mildews of cucumber were 95% and 70% by mixing application of a powdery mildew biofungicide Bacillus subtilis KB-401 and cooking oils and yolk mixture, respectively.

• The Korean Journal of Pesticide Science
• /
• v.15 no.3
• /
• pp.289-297
• /
• 2011

As part of safety evaluation of 2A (amono acid), PAT (phosphinotricin Acetyl-transferase), CtrI (Carotene desaturase) and PSY (phytoene synthase), the expressed proteins inserted to ${\beta}$-carotene Biofortified rice were tested for antigencity test. As a result, the group of administering high-concentration PAT, the expressed protein, showed a great content of total WBC; however, other expressed proteins did not show much difference. Against ASA (Active Systemic Anaphylaxis) test, the group of administering high-concentration PAT, the expressed protein, showed mild or medium degree of symptoms, but there was no dead entity. According to the result of the PCA (Passive Cutaneous Anaphylaxis test), the group of administering high-concentration PAT, 2A, PSY, and mixture of expressed proteins indicated positive response in low anti-serum concentration, and the group of administering the clinical concentration of mixture indicated mild positive response. However, because the group of administering the clinical concentration of expressed proteins, PAT, 2A, PSY, and CtrI, did not show positive response, it is thought that IgE is not generated. Further studies are needed to verify the safety of ${\beta}$-carotene Biofortified rice.

• The Korean Journal of Pesticide Science
• /
• v.12 no.2
• /
• pp.184-191
• /
• 2008

Entomopathogenic bacteria (Xenorhabdus nematophila, X. sp. and Photorhabdus temperata subsp. temperata) isolated from entomopathogenic nematodes express potent insecticidal activity in insect hemocoel. They are also known to suppress insect immune mediation by inhibiting phospholipase $A_2$, leading to host immunosuppression. This study analyzed effects of their cultured broths on inhibiting insect immunosuppression. For this, we removed all bacterial cells using $0.2\;{\mu}m$ pore sized membrane from the bacteria-cultured broth. All three sterilized cultured media, in dose-dependent manners, significantly inhibited hemocyte-spreading behavior of 5th instar larvae of Spodoptera exigua. However, they showed differential inhibitory activities among different bacterial species, in which X. nematophila showed the most potent inhibitory activity. This immunosuppressive effect was applied to increase the pathogenicity of Bacillus thuringiensis (Bt). All three bacterial cultured broths including bacterial cells significantly potentiated Bt pathogenicity against young S. exigua larvae when each of them was orally administered in a mixture of low dose of Bt. Finally, we tested the effect of oral administration of the cultured media containing the immunosuppressive compound(s) secreted by the bacteria. The membrane-sterilized cultured broths were mixed with the low dose of Bt and then orally administered to the young S. exigua. Only the cultured medium of X. nematophila showed increase of Bt pathogenicity. These results indicated that the; cultured media of the three bacteria possessed immunosuppressive factor(s), which may act to potentiate Bt toxicity to young S. exigua larvae.

• Korean Journal of Medicinal Crop Science
• /
• v.22 no.4
• /
• pp.270-275
• /
• 2014

This study was conducted to select and develop effect of eco-friendly organic materials for the eco-friendly prevention of Anthracnose occurred in the ginseng. Anthracnose on ginseng is occurred by Colletotrichum gloeosporioides and the crop damage is severe especially from July to August after rainy season. The test results showed that control effect by test products materials on the three years ginseng and four years ginseng field was lower in eco-friendly organic materials than that of chemical pesticide. However, the control effect of bordeaux mixture was higher with 71.3% and 73.8% levels than those of mineral matter, microbial agent, and developed plants extract mixtures (Eugenol, Curcumin, Wood vinegar, etc). On the other hand, three types of developed plants extract mixtures (3 types) showed control effect in a range of from 58.1% to 63.6% against Anthracnose which was higher as compared with plant extract alone and sodium silicate regardless of ages of ginseng. The results of this study would attribute in verifying the control effect of eco-friendly materials against Anthracnose for ginseng through investigating antimicrobial compounds contained in the plants body. Also, it would be used as control method against Anthracnose occurred in ginseng by judging the right control time through monitoring occurrence of disease.

• Journal of the Korean Chemical Society
• /
• v.36 no.1
• /
• pp.66-74
• /
• 1992

A method for the multiresidual simultaneous analysis of 11 thiocarbamates was studied using HPLC. Thiocarbamate in Chinese cabbage was analyzed in the order of extraction, partition, and cleanup in their optimum condition. Acetone was chosen as an extracting solvent. As a partitioning solvent, the mixture of 50% methylene chloride and petroleum ether containing extremely small water content showed good recoveries of thiocarbamate from the water layer. Partition efficiency was affected by pH of the water layer; it remained almost constant under the acidic and neutral condition while decreasing under the basic condition. The comparison done in cleanup step showed that the column chromatographic method is superior to the treatment of coagulating reagent. As an absorbent, the mixture of charcoal, magnesia, and celite with the ratio of 1 : 2 : 4 gave better recoveries and also effectively removed chlorophyll. Over the total procedure, the average recoveries for thiocarbamates in Chinese cabbage were 91% at about 2 ppm fortification level within the relative standard deviation of 8%, and the minimum detection limit (MDL) was 2.2${\sim}$9.3 ng.