• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.134-139
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• 2011

To investigate an amount of pesticide residue in rice paddy field soils and greenhouse soil, this monitoring was carried out pesticide detection frequency and concentrations collected samples from 150 rice paddy field soils and 152 greenhouse soils of nationwide in the year of 2007, and 2008, respectively. The detection limit of pesticides of this experiment were ranged 0.001~0.005 ppm. In 2007, One hundred fifty samples were collected from rice paddy field soils in April and monitored for 120 wide-used pesticides. A total of 11 pesticides were detected four fungicides, four insecticides and three herbicides in paddy field soils. The highest concentration levels of pesticide detected were 0.84 ppm as herbicide oxadiazon, 0.81 ppm as fungicide isoprothiolane and 0.50 ppm as insecticide buprofezin. The detection frequencies range were 0~19.3%, and the frequency was 2.7% as isoprothiolane and 19.3% as oxadiazon in paddy field soils. In 2008, One hundred fifty two samples were collected from greenhouse soils in April and monitored for 120 wide-used pesticides. A total of 29 pesticides were detected six fungicides, sixteen insecticides and seven herbicides in greenhouse soils. high concentration levels of pesticide detected levels were 5.09 ppm as insecticide chlorfenapyr, 2.57 ppm as fungicide chlorothalonil and 0.72 ppm as herbicide oxadiazon. The detection frequencies range were 0~38.8%, and high frequencies were 38.8% as insecticide endosulfan, 13.2% as oxadiazone, 10.5% as fungicide hexaconazole and 7.2% as isoprothiolane in greenhouse soils, Total endosulfan and oxadiazon were showed high detection frequency of 38.8% and 13.2%, respectively.

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.120-127
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• 2015

BACKGROUND: Supervised residue trials were conducted to establish pre-harvest residue limit(PHRL), a criterion to ensure the safety of the pesticide residue in the crop harvest, of amisulbrom for winter-grown cabbage in two fields. Following to application of amisulbrom on the crop, time-course study was carried out to obtain the amisulbrom dissipation of statistical significance which enabled to calculate the predicted values of PHRL. METHOD AND RESULTS: During cultivation under greenhouse condition, samples of winter-grown cabbage were collected at 0, 1, 3, 5, 7 and 10 days after amisulbrom application, and subjected to residue analysis. Analytical method was validated by recoveries ranging 93.7~100.0% as well as limit of quantitation(LOQ) of 0.04 mg/kg. Amisulbrom residues in winter-grown cabbage gradually decreased as time elapsed. The dissipation rate of the residue would be affected by intrinsic degradation along with dilution by the cabbage growth. The decay pattern was well fitted by the simple first-order kinetics. CONCLUSION: Biological half-lives of amisulbrom in winter-grown cabbage ranged 3.7~4.1 days in two field conditions. Based on the regression of amisulbrom dissipation, PHRLs of amisulbrom in winter-grown cabbage were recommended as 8.86~9.47 and 4.21~4.35 mg/kg for 10 and 5 days before harvest, respectively.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.246-252
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• 2020

BACKGROUND: Pesticides are broadly used to control weeds and pests, and the residues remaining in crops are managed in accordance with the MRLs (maximum residue limits). Therefore, an analytical method is required to quantify the residues, and we conducted a series of analyses to select and validate the quick and simple analytical method for tolpyralate in five agricultural products using QuEChERS (quick, easy, cheap, effective, rugged and safe) method and LC-MS/MS (liquid chromatography-tandem mass spectrometry). METHODS AND RESULTS: The agricultural samples were extracted with acetonitrile followed by addition of anhydrous magnesium sulfate, sodium chloride, disodium hydrogencitrate sesquihydrate and trisodium citrate dihydrate. After shaking and centrifugation, purification was performed with d-SPE (dispersive-solid phase extraction) sorbents. To validate the optimized method, its selectivity, linearity, LOD (limit of detection), LOQ (limit of quantitation), accuracy, repeatability, and reproducibility from the inter-laboratory analyses were considered. LOQ of the analytical method was 0.01 mg/kg at five agricultural products and the linearity of matrix-matched calibration were good at seven concentration levels, from 0.0025 to 0.25 mg/L (R²≥0.9980). Mean recoveries at three spiking levels (n=5) were in the range of 85.2~112.4% with associated relative standard deviation values less than 6.2%, and the coefficient of variation between the two laboratories was also below 13%. All optimized results were validated according to the criteria ranges requested in the Codex Alimentarius Commission (CAC) and Ministry of Food and Drug Safety (MFDS) guidelines. CONCLUSION: In conclusion, we suggest that the selected and validated method could serve as a basic data for detecting tolpyralate residue in imported and domestic agricultural products.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.6-12
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• 2013

Methoxyfenozide and novaluron were sprayed with single and triple treatments separately on peach during cultivation period. Samples were collected over 14 days, 8 times in total (0, 2, 4, 6, 8, 10, 12, 14 days). Methoxyfenozide and novaluron were extracted with acetone and partitioned with dichloromethane, and analyzed by HPLC/DAD. Method Quantitation Limit (MQL) were both 0.005 mg/kg, average recoveries of methoxyfenozide at two fortification levels of 0.05 and 0.25 mg/kg were determined $92.7{\pm}2.9%$ and $102.8{\pm}3.1%$, and novaluron were $98.2{\pm}4.8%$ and $96.7{\pm}9.0%$, respectively. The biological half-life of methoxyfenozide was about 4.41 days at single treatment, and 4.24 days at triple treatments. The biological half-life of novaluron was about 14.81 days at single treatment, and 14.50 days at triple treatments. Dissipation of pesticides on peach was influenced by growth dilution effect. In case of application of methoxyfenozide and novaluron following guidelines on safe use of pesticides, the final residue level was predicted to be lower than Maximum Residue Limit (MRL).

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.51-56
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• 1999

For the determination of coastal environmental contamination level of benomyl, benzimidazole pesticide, the residue of benomyl in various environmental samples on the Cheju island was monitored in May, August and October 1996, respectively. The residue of benomyl was determined as carbendazim because benomyl was converted to carbendazim (methyl 2- benzimidazolecarbamate) in the environment. The qualified limit detection of benomyl was $0.2{\mu}g/L$ in ocean water and $0.4{\mu}g/kg$ in the solid such as sediment and sea organism by HPLC with UV detector. Benomyl was not detected in any water and sediment. Moreover benomyl was neither detected in seaweed cava(Ecklonia Cava), agar(Gelidium amansii), turban sell(Batillus cornutus) and sea urchin(Anthocidaris Crassispina). Above date suggest that the benomyl used in the Cheju island is not the major source of coastal contamination.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.85-89
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• 1998

Effect of soil residue paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) on growth of barley (Hordeum vulgare L. cv. Sacheon No.6 and cv. Tapgolbori) and soybean [Glycine max (L.) Merr. cv. Alcheon and Danyeop] was investigated. Changes in soil residue paraquat during the cultivation period and residue amount in the p1ants at harvest were also determined. Experiments were conducted at two paraquat residue conditions; the first was done in an apple orchard soil where paraquat residue recorded 30.2 ppm in 1996, but decreased to about 9 to 9.8 ppm at the time of crop seeding and the second was conducted in the soil fortified to about 27 to 32 ppm paraquat residue. In both conditions, no crop injury due to the residue paraquat was observed and number of emerged seedlings and plant height of the two crops were not affected by soil residue paraquat. Residue amount of paraquat in the plants occurred less than 0.5 ppm detection limit. At the first condition, soil residue paraquat was further slightly decreased for 90 days after seeding, while no great change in the residue level was found at the second condition for 30 days after seeding. The results suggest that no carry-over effect occurs at about 30 ppm of soil residue paraquat and at present crop cultivation in Korean orchard soils are safe with respect to crop growth and paraquat residue in the plants.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.306-320
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• 2015

This survey was carried out in 2014 to estimate the pesticide residue levels in commercial environment-friendly agricultural products in Seoul metropolitan area. Pesticide residues in 27 commodities were examined and analyzed using LC-MS/MS, which can simultaneously detect up to 85 pesticides. A total of 441 samples were collected and analyzed. Among the detected samples, the residue levels in 1.2% of organic agricultural products and 2.2% of pesticide-free agricultural products exceeded the maximum residue limits (MRLs); hence, 1.8% of the total samples exceeded the MRLs. The safety of the detected pesticides was assessed by monitoring the acceptable daily intake level (ADI) and acceptable dietary exposure (ADE) to the pesticides via consumption of the commodities. ADI and ADE are found to be 0.07728-9.46530% and 0.00141-0.17210%, respectively, which means that the residual pesticides in the environmental-friendly agricultural products in Korea are below the safe limit and therefore, pose no potential public health risks.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.121-130
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• 2012

In analyzing pesticide residue, LLE (liquid liquid extraction) is generally applied as one of the existing methods, but needed quite a lot of organic solvents and analytical apparatuses for the sample pre-treatment. In addition to its long analysis time and complex analytical processes, it is required to develop a more rapid and efficient method at present. In order to establish an economic and simple pesticide residue analytical method, this study carried out a comparative experiment on the existing analytical method with a new sample pre-treatment method named QuEChERS (quick, easy, cheap, effective, rugged and safe), which extracts and refines pesticide components by directly adding solid powder into the sample. Both the two analytical methods showed favorable values of correlation coefficient ($R^2$ > 0.99) of calibration curves. In terms of the detection limit (identification limit), imidacloprid showed 0.02 mg/kg, while the rest of pesticides showed a level around 0.05 mg/kg. The results of this experiment revealed that the recovery of LLE was 92.8-100.9% and the RSD was below 2.5%. On the other hand, the recovery of QuEChERS was 92.2-101.6% and RSD was below 1.9%. As a result of comparing the amount of pesticide residue by the time between the two analytical methods by using Paired t-Test, there was no significant difference between the two analytical methods as the p-value ranged from 0.3148-0.9890. Considering the results of the two methods, the QuEChERS method had similar recovery, compared to the analytical method using the existing LLE, and the analytical time was shortened by about one fourth of that of the existing method. Moreover, since it excludes the use of harmful organic solvents like dichloromethane during the process of extraction, thus leading to protecting experimenters health and remarkably reducing the amount of disused solvents, it is judged as an echo-friendly and economic analytical method.

• Korean Journal of Environmental Agriculture
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• v.42 no.2
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• pp.93-103
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• 2023

Persistence and degradation patterns of acequinocyl and its metabolite, hydroxyl-acequinocyl (acequinocyl-OH) and fenpyroximate in butterburs (Petasites japonicus Max.) were investigated after pesticide application. Butterburs, one of the minor crops in South Korea, was planted in two plots (plot A for double and plot B for single application) in a greenhouse. Butterburs samples were also planted in a separate plot without pesticide treatment, as the control. A commercial pesticide containing acequinocyl and fenpyroximate was applied to the foliage of butterburs at hourly intervals after dilution. Recoveries of acequinocyl and acequinocyl-OH were 78.6-84.7% and 83.7-95.5%, respectively; the relative standard deviation of the two compounds were less than 5%. The method limit of quantification was 0.01 mg/kg. The total (Ʃ) acequinocyl residues in butterburs reduced by 96.0% at 14 days and 75.9% at 7 days, in plot A and B, respectively, after final pesticide applications. The biological half-life (DT₅₀) of Ʃ acequinocyl and fenpyroximate, calculated using the dissipation rate, was 3.0 days and 4.0 days, respectively. These data were used to set up maximum residue and safe standard levels when the pesticides are applied to control pests during butterbur cultivation. Risk assessment results showed that the maximum % acceptable daily intake was 7.74% for Ʃ acequinocyl and 0.16% for Ʃ fenpyroximate. The theoretical maximum daily intake of Ʃ acequinocyl and fenpyroximate was 26.3% and 35.8%, respectively. In conclusion, the concentrations of Ʃ acequinocyl and fenpyroximate in butterburs pose no significant health risks to Koreans.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.871-877
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• 1995

Dietary intake and oncogenic risk of 12 pesticides used in Korea whose oncogenic potency was known were assessed from published data. Dietary oncogenic risk (excess tumor incidence for a 70-year human life span) for Korean population was estimated to be $2.17{\times}10^{-3}$ on the basis of legal maximum residue limit, $4.33{\times}10^5$ on the basis of maximum practical residue level and $5.10{\times}10^{-6}$ on the basis of mean practical residue level of examined pesticides, all of which exceeded the negligible risk standard $1{\times}10^{-6}$ of US EPA. A systematic follow-up study on those oncogenic pesticides should be undertaken in order to mitigate the people's worry about the cancer risk by the abuse of pesticides in food production.