• Korean Journal of Environmental Agriculture
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• v.25 no.2
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• pp.174-179
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• 2006

Chinese cabbage, Braccica campestris has long been consumed as a staple food for Koreans in various forms of fresh, salted, and fermented Kimchi. Cultivation of the crop under greenhouse has become a general practices to fulfill its off-seasonal consumer's demand. However, agricultural practices of the crop have always accompanied with heavy applications of pesticides caused by severe outbreaks of diseases and pose under warm and humid circumferences. Since dissipation patterns of pesticide residues in/on the crop under greenhouse conditions ate quite different from those in the open-air, changes of diazinon, O,O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphornthioate, in/on the Chinese cabbage applied by foliar spraying under greenhouse were studied. Diazinon 34% EC was applied with dilution of recommended and double dose to the crop. The shoots of crop were harvested immediately after this application and at regular intervals over a 10-day. After sample preparations, the diazinon residue was analyzed using gas chromatography equipped with electron capture detector (GC/ECD). Initially deposited amount of the chemical in/on the crop right after applications with recommended and double doses were 8.3 and 15.2 mg/kg, respectively. The residue levels after 10 days of application were 0.03 and 0.09 mg/kg with 1.3 and 1.5 days of half-life in/on the crop, respectively. In consequent 10 days of pre-harvest interval (PHI) for diazinon EC formulation in/on Chinese cabbage under greenhouse condition was fulfill maximum residue level set by Korea Food and Drug Administration (KFDA, 0.1 mg/kg).

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.31-37
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• 1987

A study has been conducted to investigate the behavior of carbofuran in a miniature paddy agrosystem simulated for paddy field. Carbofuran applied onto the paddy water was rapidly absorbed and translocated into rice plants. Carbofuran concentration in rice plant reached its maximum level between 1 to 3 days after treatment and gradually decreased thereafter. Half life of carbofuran concentration in paddy water was 4 days in both application rates of 0.12 and 0.24Kg a.i./10a. Carbofuran residue in paddy soil was gradually dissipated with the half life of 8 and 12 days in 0.12 and 0.24㎏ a.i./l0a respectively. Range of carbofuran residue in brown rice and rice straw harvested from the paddy agrosystem was 0.01∼0.02 ppm and 0.37∼0.57 ppm irrespective of the two application rates respectively.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.373-381
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• 1997

In order to investigate the drift of pesticides sprayed on Chinese cabbage, 7 pesticides chlorpyrifos, EPN, pirimiphos-methyl, phenthoate, tetradifon, dicofol and bifenthrin were applied in two sets of field tests. The pesticide residues were quantified bar multiple-residue analysis, in which the recovery rate was 78${\sim}$92% and standard deviation was ${\pm}0.683{\sim}52%$. It was found that most of the tested pesticides were spread by drift to neighbouring area and brought about the contamination of the unsprayed crops. The extent of drift varied depending upon the pesticide, distance and wind direction. The mean residue levels on unsprayed crops were 0.66% at 3 meter distance, 0.10% at 6 m distance and 0.05% at 9 m distance from the applied area and the maximum level was 1.83% of the residue on sprayed crops.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.1022-1035
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• 2021

This study estimated the effect of exposure to propiconazole through implementation and residues in finishing pigs. We analyzed the expression of fibrosis-related genes and performed histological analysis of the blood, liver, kidney, muscle, ileum, and fat tissues. The animals were exposed for 28 d to different concentrations of propiconazole (0.09, 0.44, 0.88, 4.41, and 8.82 mg/kg bw/d). Quantitative, gene expression, and histological analyses in tissues were performed using liquid chromatography mass spectrometry, real-time PCR, and Masson's trichrome staining, respectively. Final body weight did not differ among groups. However, genes involved in fibrosis were significantly differentially regulated in response to propiconazole concentrations. Glucose, alanine aminotransferase, and total bilirubin levels were significantly increased compared with those in the control group, while alkaline phosphatase level was decreased (p<0.05) after exposure to propiconazole. The residue limits of propiconazole were increased in the finishing phase at 4.41 and 8.82 mg/kg bw/d. The liver, kidney, and ileum showed blue staining after propiconazole treatment, confirmed by Masson's trichrome staining. In conclusion, these findings suggest that propiconazole exposure disturbs the expression of fibrosis-related genes. This study on dietary propiconazole in pigs can provide a basis for determining maximum residue limits and a better understanding of metabolism in pigs and meat products.

• Food Science of Animal Resources
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• v.42 no.4
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• pp.712-722
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• 2022

In this study, we investigated the residual properties of tebuconazole-treated pigs. Twenty pigs were treated with different concentrations (0.25, 1.25, 2.5, 12.5, and 25 mg/kg bw/d) of tebuconazole for 28 d. Blood biochemistry, histology, and residual levels were analyzed using the VetTest analyzer, Masson's trichrome staining kit, and liquid chromatography-mass spectrometry, respectively. The final body weights were not significantly different between the control and treatment groups. Alkaline phosphatase, blood urea nitrogen, cholesterol, and gamma-glutamyl transpeptidase levels were significantly different from those of the control after exposure for 14 d. However, alanine aminotransferase levels showed changes only after exposure to pesticides for 28 d. The biochemical parameters were separated during the experimental period (14 d versus 28 d) by principal component analysis. Based on variable importance plots, blood urea nitrogen/creatinine ratio, blood urea nitrogen, glucose, and gamma-glutamyl transpeptidase are candidate biomarkers for tebuconazole exposure. The residual levels were observed at T4 (12.5 mg/kg bw/d) and T5 (25 mg/kg bw/d) in the liver and fat tissues, respectively. Fibrosis increased in the liver, kidney, and fat tissues, depending on the tebuconazole concentration. In conclusion, the residue limits of tebuconazole and the physiological changes caused by dietary tebuconazole in pigs provide important information for establishing maximum residue limits of pork and pork products.

• The Korean Journal of Pesticide Science
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• v.11 no.1
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• pp.27-31
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• 2007

Trifloxystrobin standard was analyzed by high performance liquid chromatography (HPLC). The recovery of the trifloxystrobin and it's metabolite CGA321113 were $84.6{\sim}95.3%$ and $86.4{\sim}87.3%$ and their detection limits for both of them were 0.04 mg $kg^{-1}$. In case of foliar application in the chinese cabbage (Brassica campestris L. ssp pekinnensis (Lour.) Rupr.), the amount of the residue of trifloxystrobin was above the maximum residue level (temporary MRL, 0.5 mg $kg^{-1}$) when it was treated either two times three to five days before harvest or three times three to seven days before harvest. Whereas in case of drenching the mount of the residue was below the temporary MRL, the residues in the cabbage in both the cases where the recommended amount (150 mL of the solution diluted 1500 times) and double of the amount were treated were 0.16 and 0.31 mg $kg^{-1}$, respectively. In conclusion, it should be safe to apply the trifloxystrobin (22% WP) in the soil of cabbage field abiding by the tentative recommendation level, but for the foliar application it appeared inappropriate.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.43-49
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• 2017

BACKGROUND: Greenhouse crops are one of agricultural products consumed largely in Korea. Cucumber is a typical example as main vegetables of greenhouse crops. Thus, pesticide residue analysis is an important requirement to guarantee pesticide safety of cucumber. This work was aim to investigate the residues of penthiopyrad and pyriofenone in cucumber after harvest. METHODS AND RESULTS: Cucumber was subjected to treat with penthiopyrad and pyriofenone at a level of recommended dose 0, 1, 2, 3, 5, 7 and 10 days before harvest under greenhouse conditions. The samples were extracted with organic solvent by using a homogenizer and purified on solid phase cartridge column followed by LC-MS/MS analysis. The recovery levels of penthiopyrad and pyriofenoneranged from approximately 81 to 93% with the method limit of 0.005 mg/kg and coefficient of variation less than 10%. Penthiopyrad and pyriofenone were detected at a level less than maximum residue limit in cucumber at 10 days before. The half-lives of penthiopyrad and pyriofenone were determined to 2.4 ~ 2.6 days. CONCLUSION: Penthiopyrad and pyriofenone are suggested to use in cucumber 10 days before harvest to reach their levels less than maximum residue limit.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.376-378
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• 2012

Aflatoxin M1, ingested as aflatoxin B1 via contaminated feedstuff and later converted into, is a major problematic target for milk safety control among the aflatoxin class. Korean government has controlled level of AFM1 in milk at 500 ppt as maximum residue level (MRL), and more recently, government also publicized the proposal for more strict control on fungal toxins about infant and baby foods. In this study the levels of Aflatoxin M1 (AFM1) of 42 marketed milk samples were determined with Enzyme-Linked Immunosorbent Assay (ELISA) to evaluate the status on the contamination of Aflatoxin M1. The evaluated ELISA performances of limit of detection (LOD) and the half maximal inhibitory concentration ($IC_{50}$) were 5 pg/mL (ppt) and 49 ppt, respectively. In all 42 samples, AFM1 appeared above the 5 ppt, with the average of 21 ppt and the range of up to 90 ppt. Only 3 (7%) of samples showed the level of contamination above the EU MRL (50 ppt). Although there was incidence of higher level of contamination compared with previous reports, the result of this study requires more intensive study to control of AFM1 in milk and infant foods.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.220-226
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• 2007

For the analysis of hazard factors and the development of GAP (Good Agricultural Practices) Ginseng, 10 ginseng cultural farms wished certified GAP were selected at Geumsan-gun area, a representative site of ginseng cultivation in Korea. In order to verify the safety of GAP ginseng, possible contamination of pesticide and heavy metal residues, and microbial hazard were analyzed. Soil and water around ginseng cultivation field, and ginseng were investigated. Eighty-one pesticides including carbendazim were used as typical pesticide against plant pathogens and insect pests of ginseng plant and general crops. There was no excess the maximum residue limit (MRL) in residue figure of the soil. Including the residue figure of the arsenic (0.81 ml/kg) and 7 other heavy metals was also suitable to cultivate the ginseng plant. The irrigation water and dilution water for pesticide application were also safety level for GAP. Fresh ginsengs from the farms were sampled and investigated pesticide residues and contaminations of bacteria. Among 23 pesticides tested, we didn't detect any kinds of pesticide residues, but tolclofos-methyl was frequently found in the other ginseng field. On the investigation of microorganism hazards, 2 gram negative bacteria and 1 gram positive bacterium were found in the fresh ginseng. Number of total bacteria was $1.5{\times}10^3$ cfu/ml, which was less than the other agriculture products. At these results, 10 selected ginseng farms were good cultural places for GAP ginseng production and the ginseng cultured from Geumsan-gun area were a good safe far human.

• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.1-7
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• 2014

The present study was performed to investigate the pre-harvest residue limit (PHRL) of pesticides namely, metalaxyl-M and flusilazole in oriental melon, and to identify the biological half-life and characteristics of their residues. In this study, pesticides were sprayed once as single spray and double spray on oriental melon. The oriental melon samples were collected at 0, 1, 2, 3, 5, 7, 9 and 11 days before harvest and samples were extracted with QuEChERS method. The residues of both the pesticides were quantified using GC/NPD and LC/MS/MS. The limit of detection was found to be 0.02 mg/kg and 0.01 mg/kg and their recoveries were greater than 95% (95.7% ~ 103.2% for metalaxyl-M and 100.2% ~ 106.8% for flusilazole) for both pesticides. The biological half-lives of both metalaxyl-M and flusilazole were 12 days at single and double spray, respectively. The PHRL of metalaxyl-M and flusilazole was found 1.0 mg/kg and 0.3 mg/kg, respectively for 10 days before harvest. The results of the present study shows the residual level of both the pesticides metalaxyl-M and flusilazole in oriental melon were less than their maximum residual limits.