• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.15-21
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• 2011

Monitoring or follow-up surveying pesticide residues in agricultural commodities is the key to meet the international regulations and to enhance international competitiveness of Korean agricultural commodities. Six neonicotinoid insecticides, acctamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam were monitored in 95 paprika samples collected from Gyeongnam area. Thc pesticide residues were extracted by EN 15662 buffer based on the QuEChERS method, clean-upped with dispersive solid-phase extraction method to remove interfering pigments, and analyzed using UPLC-MS/MS. The neonicotinoid pesticides were detected in 90.5% of the paprika samples. Two or more pesticides were detected in 82.3% of samples. Although detection frequencies were high, all samples complied with the maximum residue limits (MRLs) set by both the Korea Food and Drug Administration (KFDA) and Japanese Ministry of Health, Labour and Welfare.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.32-40
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• 2015

This study was implemented to evaluate food safety on residual pesticides in agricultural products of Korea and to use as a data base for the establishment of food policy. A total of 196 pesticide upon these products were analyzed using multi class pesticide multiresidue methods of Korean Food Code, and 232 samples of 15 agricultural products collected from 9 regions were supplied for this study. In the results, 64 kinds of pesticides were detected in 53 samples, chlorpyrifos and procymidone of them were shown a high frequency of detection in the analyzed pesticides. Among them, two samples (chlorpyrifos in perilla leaves and picoxystrobin in peach) were detected over Maximum Residue Limits (MRLs). The levels of the detected pesticide residues were within safe levels. Also, the intake assessment for pesticide residues including chlorpyrifos at multi pesticide residue monitoring were carried out. The result showed that the ratio of EDI (estimated daily intake) to ADI (acceptable daily intake) was 0.001~0.902% which means that the detected pesticide residues were in a safe range so that residual pesticides in the agricultural products in Korea are properly controlled.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.470-478
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• 2021

This study was conducted to monitor residual pesticides in a total of 527 school foodservice agricultural products from 2019 to 2020 in Incheon. Pesticide residues in the samples were analyzed by the multi-residue method in the Korean food code for 373 pesticides using GC-MS/MS, LC-MS/MS, GC-ECD, GC-NPD, and HPLC-UVD. By monitoring the pesticides, 12 (2.3%) of the 527 pesticides were detected, and 2 (0.4%) samples exceeded the maximum residue limit. Twelve types of pesticides were detected in the agricultural products of carrot, chard, chili pepper, chwinamul, crown daisy, parsley, perilla leaves, and spinach. As a means of risk assessment through the consumption of agricultural products detected with pesticide residues, the proportion of estimated daily intake to acceptable daily intake was estimated in the range of 0.0000-39.7425%. Results showed no particular health risk through the consumption of school foodservice agricultural products with pesticide residues.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.338-351
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• 2019

BACKGROUND: To investigate distribution and seasonal variation of concentration and flux of pesticides in Han river basin, water samples were examined at 24 sites in 2012 and 2014. METHODS AND RESULTS: Water samples were collected four times per year and subjected to liquid-liquid partition extraction followed by GC-ECD/NPD analysis. Of fifteen pesticides detected, iprobenfos, diazinon, isoprothiolane, endosulfan sulfate and oxadiazon were detected in a higher frequency, while fenoxanil, carbofuran, fenitrothion, butachlor and metolachlor were only detected in a sample. Pesticides with high occurrences, iprobenfos, diazinon, isoprothiolane, endosulfan sulfate and oxadiazon were detected in residue level of 0.01-0.46, 0.01-0.24, 0.03-0.85, 0.02-0.06 and 0.05-0.24 ㎍/L, respectively. Carbofuran and acetanilide herbicides were found at lower frequencies, but their concentrations were one order of magnitude higher than those of the others. CONCLUSION: Discharge of pesticides in downstream area were mainly contributed from rice farming and suburban horticulture, while pesticide occurrences in upstream area, such as Donggang river basin were caused by highland agriculture for cabbage and potato production. Despite the influx of pesticides from tributaries through intensive agriculture areas, pesticide concentration in the main stream water was low due to the dilution effect from the upstream. Therefore, the water quality was considered to be good at the most downstream, the effluent of Paldang dam.

• Journal of Food Hygiene and Safety
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• v.7 no.2
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• pp.121-132
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• 1992

Pesticides are regarded as one of indispensable materials used in agriculture to protect pests and to keep the agricultural productions steadily. However, food contamination arisen from their application has brought about public concerns for safety suspicion to human health. A brief presentation is given in this paper on what has been conducted against pesticide residues to evaluate and ensure the safety of agro-porducts. The commonest countermeasures to keep safety would be tile establishment of MRls and safe-use guidelines of pesticides according to good agricultural practices. Korean MRls have been established on 38 chemicals with 56 commodities and in the case of safe-use guidelines 344 formulation items have been done by the government On the other hand, no satisfactory information is still available to evalute the actual residue levels in domestic agro-products, but a cautious proposal could be suggested through the fragmentary monitoring data of pesticide residues, so that the current residue levels would be far from potent hazard enough to cause chronic impact on human. The most important thing is to have the farmers keep safe use guidelines at pesticide application for the production of safe agricultural commodities.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 1992.07a
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• pp.21-32
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• 1992

Pesticides are regarded as one of indispensable materials used in agriculture to protect pests and to keep the agriculture productions steadily. However, food contamination arisen from their application has brought about public concerns for safety suspicion to human health. A brief presentation is given in this paper on what has been conducted against pesticide residues to evaluate and ensure the safety of agro-products. The commonest countermeasures to keep safety would be the establishment of MRLs and safe-use guidelines of pesticides according to good agricultural practices. Korean MRLs have bun established on 38 chemicals with 56 commodities and in the case of safe-use guidelines 344 formulation items have been done by the government. On the other hand, no satisfactory information is still available to evalute the actual residue levels in domestic agro-products, but a cautious proposal could be suggested through the fragmentary monitoring data of pesticide residues, so that the current residue levels would be far from potent hazard enough to cause chronic impact on human. The most important thing is to have the farmers keep safe use guidelines at pesticide application for the production of safe agriculture commodities.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.34-42
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• 2008

In order to know the residual pattern of some pesticides and predict to the degradation period until below MRL, we experimented chlorothalonil, indoxacarb, lufenuron, metalaxyl and methomyl for Chinese cabbage. They were frequently detected pesticides in Chinese cabbage by NAQS (National Agricultural product Quality management Service) monitoring survey. In this experiment, we sprayed those pesticides 10days before harvest and analyzed 0, 1, 2, 3, 5, 7, 10 day samples to establish logical equation and to calculate $DT_{50}0$. During the cultivating period, the residue amount of chlorothalonil was changed from $55.58\;mg\;kg^{-1}$ (0 day) to $20.08\;mg\;kg^{-1}$ (10 day), $DT_{50}$ was 7.45 days, indoxacarb was $7.85\;mg\;kg^{-1}$ (0 day) to $1.46\;mg\;kg^{-1}$ (10 day), and 4.2 days, lufenuron was $1.57\;mg\;kg^{-1}$ (0 day) to $0.49\;mg\;kg^{-1}$ (10 day), and 5.85 days, metalaxyl was $8.12\;mg\;kg^{-1}$ (0 day) to $0.10\;mg\;kg^{-1}$ (10 day), and 175 days, and methomyl was $11.51\;mg\;kg^{-1}$ (0 day) to $0.80\;mg\;kg^{-1}$ (10 day), and 2.42 days at single dose application, respectively. The $DT_{50}$ of double amount in those pesticides were 9.05 days in chlorothatonil, 7.09 days in indoxacarb, 8.82 days in lufenuron, 3.32 days in metalaxyl, and 2.72 days in methomyl, respectively.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.289-296
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• 2019

A novel rapid procedure with liquid chromatography tandem mass spectrometry (LC-MS/MS) detection has been developed by changing various conditions including sample preparation such as QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) methodology. This work has been involved the optimization and validation of detection method for fluoroquinolones which are widespread used in livestock especially in the chicken. Five grams of homogenized chicken muscle were extracted with QuEChERS EN and acetonitrile containing 5% formic acid and cleaned with anhydrous magnesium sulfate and C₁₈ sorbent. The separation was performed on Acquity UPLC HSS T3 (2.1 mm×100 mm, 1.8 ㎛) column. The mobile phase A and B were composed of water containing 0.1% formic acid and acetonitrile containing 0.1% formic acid, respectively. Flow rate was 0.25 mL/min and column temperate was 40℃. LC-MS/MS with multiple reaction monitoring has been optimized for ten fluoroquinolones (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, marbofloxacin, norfloxacin, ofloxacin, orbifloxacin, pefloxacin and sarafloxacin). The method developed in this study has been presented good linearity with correlation coefficient (R²) of 0.9971~0.9998. LOD and LOQ values ranged from 0.09 to 0.76 ppb and from 0.26 to 2.29 ppb, respectively. The average recoveries were from 77.46 to 111.83% at spiked levels of 10.0 and 20.0 ㎍/kg. Relative standard deviation (%) ranged 1.28~11.90% on intra-day and 3.10~8.38 % on inter-day, respectively. This analysis method was applicable to the livestock residue laboratories and was expected to be satisfactory for the residue surveillance system.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.37-48
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• 2010

The diacylhydrazine insecticides, methoxyfenozide, chromafenozide and tebufenozide are new-generation insecticides. These insecticides induce premature molting and cause the death of insects by mimicking their hormone. Also, these insecticides have already been widely used for vegetables planting in worldwide. Highperformance liquid chromatography (HPLC) is the most widely used procedure for determination of each compound residues in crops. However, simultaneous analysis method of these diacylhydrazine insecticides was not reported. The purpose of this study is to develop a simultaneous determination procedure of methoxyfenozide, chromafenozide and tebufenozide residue in crops using HPLC-UVD/MS method. These insecticide residues were extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, apple, pepper, and Chinese cabbage. The extract was diluted with saline water, and dichloromethane partition was followed to recover these insecticides from the aqueous phase. Florisil column chromatography was additionally employed for final cleanup of the extracts. The analytes were quantitated by HPLCUVD/MS, using a $C_{18}$ column. The crops were fortified with each insecticide at two levels per crop. Mean recoveries ranged from 89.0 to 104.8% in five representative agricultural commodities. The coefficients of variation were less than 3.9%. Quantitative limits of methoxyfenozide, chromafenozide and tebufenozide were 0.04 mg/kg in crop samples. A HPLC-UVD/MS with selected-ion monitoring was also provided to confirm the suspected residues. The proposed simultaneous analysis method was reproducible and sensitive enough to determine the residues of methoxyfenozide, chromafenozide and tebufenozide in agricultural commodities.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.427-434
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• 2017

Species that belong to the Acinetobacter calcoaceticus-baumannii (Acb) complex are major causes of hospital-acquired infections. They are important opportunistic pathogens. These species are usually multidrug resistant (MDR), and the therapeutic options to treat the infections caused by these species are limited. In the present study, we investigated fluoroquinolone resistance mechanisms in 53 ciprofloxacin resistant Acinetobacter species isolates in Chungcheong, Korea. Antimicrobial susceptibilities were determined using the disk-diffusion method. Detections of genes and identification of mutations associated with fluoroquinolone resistance were carried out using PCR and DNA sequencing. In our study, 47 out of 53 ciprofloxacin resistant Acinetobacter isolates harbored sense mutations at the 83rd residue (serine to leucine) in the gyrA gene as well as at the 80th residue (serine to leucine) in the parC gene. Among the 47 isolates harboring sense mutations in gyrA and parC gene, 44 isolates were A. baumannii and 3 isolates were A. pittii. Plasmid-mediated quinolone resistance (PMQR) determinants were detected in isolates in our study. Among the 46 ciprofloxacin resistant A. baumannii isolates, 41 showed type A, B, or F banding patterns on their REP-PCR profiles. This result suggests that clonal relation and horizontal spreading of the bacterial isolates have been around hospitals in Chungcheong area. To prevent colonization and disseminations of fluoroquinolone resistance Acb complex isolates, continuous investigation and monitoring of antimicrobial resistant determinants of MDR isolates are needed.