• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.194-201
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• 2009

To evaluate the exposure of non-point source pesticide pollution in agricultural watershed and to investigate pesticide distribution and runoff from agricultural land, paddy field, upland and orchard, this experiment was carry out during crop growing seasons. The pesticide were detected twenty pesticides fungicide 4, insecticide 10, herbicide 6) in water of Neungchon agricultural watershed and detection concentrations were range 0.008${\sim}$7.59 ppb. Most of the detection pesticides were using pesticides to rice paddy fields to control fungi, insects, weeds. During the crop cultivation, the pesticide were detected total thirty pesticides by pepper field soil 6, orchard soil 4, sesame field soil 3 and rice paddy field soil 5, and pesticide concentrations were range 0.001${\sim}$0.109 ppm. Especially the herbicides were detected mainly in May and June in the stream water. The pesticide were detected thirty pesticides by fungicide 2, insecticide 6, herbicide 5 in water of Jungam Koseong agricultural watershed and detection concentrations were range 0.01${\sim}$7.21 ppb. In regard to the detected pesticides, the concentration of individual pesticides measured in surface water of the study areas never exceeded guidelines for agriculture chemicals concerning water quality-effluent from paddy fields in Japan (Katayama, 2003). Runoff rate of pesticides was range 0.07${\sim}$3.06 % from Kongju agricultural land to watershed after applied pesticides.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.148-154
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• 2008

This study was carried out to investigate the residue patterns of two insecticides, lambda-cyhalothrin and deltamethrin, commonly used for lettuce, under greenhouse conditions. The pesticides were sprayed with dilution of recommended and doubled doses onto lettuce. Their detection limits were $0.001\;mg{\cdot}kg^{-1}$ and mean recoveries at the fortification levels of 0.2 and $1.0\;mg{\cdot}kg^{-1}$ were from 101.17 to 104.25 and from 99.70 to 103.77%, respectively. The pesticides were gradually decreased in lettuce with time. Biological half-lives of lambda-cyhalothrin and deltamethrin were 1.7 and 1.4 days at the recommended dose and 1.8 and 1.4 days at the doubled dose, respectively. Initial residue amounts of lambda-cyhalothrin and deltamethrin at the recommended and doubled doses exceeded their MRLs. However, the residue levels of the pesticides in the crop sampled at harvest were less than their MRLs. The ratios of the estimated daily intake (EDI) to acceptable daily intake (ADI) by intake the crop harvested 10 days after spraying were less than 1% of their ADIs.

• 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.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.236-246
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• 2014

Pesticide is used to protect the crops, but also become a cause of polluting the environment. Perform a risk assessment using physical and chemical properties, environmental fate and toxicity data in order to determine the pesticide registration. The aquatic model estimates pesticide concentrations in water bodies that result from pesticide applications to rice paddies and apple orchard. The used models are the PRZM, EXAMS and AGRO shell (PA5), Rice Water Quality Model (RICEWQ) and Screening Concentration In GROund Water (SCI-GROW). The residual concentration of water body was estimated using meteorological data, crop calendar and soil series of Korea. The chosen pesticides were butachlor, carbofuran, iprobenfos and tebuconazole. It has shown the potential that the RICEWQ is possible to predict residue level in water of butachlor and iprobenfos, because the maximum value in water monitoring data is lower than the peak concentration of the model, and the minimum value is lower than the average annual concentration of the model. But RICEWQ was insufficient to predict exposure concentrations in ground water. The estimated exposure concentrations of carbofuran in ground water is very higher than in surface water because of its low soil adsorption coefficient. Although tebuconazole were not detected in the water monitoring that means very low concentration, it is possible that the PA5 can be used to predict residue level in water.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.306-312
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• 2006

The objective of this study was to compare the reduction of residues in/on mini-tomato by washing methods and to evaluate the relation of reduction rates in different pesticides. Mini-tomato was sprayed with three commercial pesticides, oxadixyl, thiophanate-methyl and chlorothalonil, and harvested for washing test as 0, 5 and 7 days elapsed. The reduction rates of oxadixyl in/on mini-tomato were 61, 11 and 4%, those of thiophanate-methyl were 89, 89 and 79%, and in case of chlorothlaonil, reduction rates were 84, 84 and 88%, respectively When mini-tomato at 0 day and 5 days after spray was washed by 0.02% of $Sur-ten^{(R)}$ solution, its pesticide residues were reduced by 81 and 55% on oxadixyl, 95 and 91% on thiophanate-methyl, and 97 and 98% on chlorothlaonil. When three wettable powdered pesticides with the same recipe were sprayed, their reduction rates in/on mini-tomato by washing with water at 0, 5 and 7 days were 76, 66 and 43% on oxadixyl, 91, 83 and 82% on thiophanate-methyl, and 65, 68 and 82% on chlorothlaonil, suggesting that the washing effect may be dependent on the amounts of active ingredients and inert types of the pesticides used.

• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.107-116
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• 2013

Polar pesticides like pymetrozine (log $P_{ow}$: -0.18) are known to be difficult to analyze. The analytical method of pymetrozine using hydromatrix included in the official method of KFDA was uncommon and provided ambiguous evidence to confirm both the identity and the quantity. Therefore, precise single residue analytical method was developed in representative crops for using liquid-liquid extraction (LLE). The pymetrozine residue was extracted with methanol from 11 representative crops which comprised apple, blueberry, broccoli, cabbage, cherry, crown daisy, hulled rice, Korean cabbage, potato, rice and watermelon. The extract was purified serially by liquid-liquid extraction (LLE) and silica solid phase extraction (SPE). For rice and hulled rice samples, n-hexane partition was additionally adopted to remove nonpolar interferences, mainly lipids. The residue levels were analyzed by HPLC with DAD, using $C_8$ column. LOQ (limit of quantitation) of pymetroizinie was 1 ng (S/N > 10) and MQL (method quantitation limit) was 0.01 mg/kg. Mean recoveries from 11 crop samples fortified at three levels (MQL, 10 ${\times}$ MQL and 50 ${\times}$ MQL) in triplicate were in the range of 83.1~98.5% with coefficients of variation (CV) of less than 10%, regardless of sample type, which satisfies the criteria of KFDA. The method established in this study could be applied to most of crops as an official and general method for analysis of pymetrozine residue.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.302-307
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• 2012

This study was carried out to elucidate residual characteristics of environment friendly agricultural material rotenone in chilli pepper and calculate processing factors by drying. The test material was sprayed twice onto chilli peppers at an interval of seven days and then the chilli peppers were harvested at 0, 1, 3, 5 and 7 days after final spray. Limits of quantitation (LOQs) of rotenone in fresh and dried chilli peppers were 0.03 and 0.07 mg/kg, respectively. Recoveries of the test material in fresh and dried chilli peppers ranged from 89.52 to 97.86% and from 85.76 to 91.61%, respectively. As a results of residual material analysis, amounts of rotenone in fresh and dried chilli peppers ranged from 0.03 to 0.39 mg/kg and from 0.07 to 0.75 mg/kg, respectively, representing that the residual amounts of rotenone decreased time-coursely. Processing factors of rotenone in fresh chilli pepper by drying were found to be from 2.03 to 3.13, indicating that the residual concentration of rotenone in dried chilli pepper increased from two to three times by drying. However, the reduction factor of rotenone in fresh chilli pepper by drying ranged from 0.38 to 0.59, representing that some of rotenone in fresh chilli pepper disappeared during the drying process.

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.199-208
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• 2007

Three pesticides commonly used in perilla leaf were subjected to a field residue trial to ensure safety of terminal residues in the harvest. The residual patterns of three pesticides, which were dimethomorph, indoxacarb and procymidone were examined after applying with the recommended and double dose and their DT50 were calculated. Also degradation patterns of pesticides at storage $4^{\circ}C$ were compared to those at $20^{\circ}C$, and removal rates of pesticides by washing perilla leaf with water were measured. Biological half-lives of dimethomorph, indoxacarb and procymidone were $2.91{\sim}3.11,\;2.53{\sim}3.14\;and\;2.62{\sim}2.92$ days, respectively. During the storage period, the degradation patterns were appeared more obviously at $20^{\circ}C$ than $4^{\circ}C$. Removal rates of dimethomorph, indoxacarb and procymidone were $51.3{\sim}73.3%,\;74.1{\sim}91.3%\;and\;57.9{\sim}81.6%$by various washing methods.

• Journal of Food Hygiene and Safety
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• v.30 no.2
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• pp.196-201
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• 2015

This study was conducted to monitor the current status of pesticide residues and to calculate the correlation between monthly price fluctuation and distribution of pesticide residues in leafy vegetables at the whole market in Gyeonggi-do from 2009 to 2013. From the result, the maximum residue limit (MRL) were frequently exceeded in 5 leafy vegetables which were 48 cases of crown daisy (5.8%), 28 cases of chard (5.1%), 28 cases of spinach (3.4%), 25 cases of perilla leaves (3.4%) and 24 cases of chamnamul (3.7%). The high rate of monthly pesticide residues exceeding MRL showed on crown daisy and chard observed in June and September, spinach in October to November and December to January, perilla leaves in July to August and January, and chamnamul in August to September. To calculate the correlation between monthly price fluctuation and distribution of pesticide residues, we performed the Pearson's correlation analysis. From the results, there were significant differences between monthly price and pesticide residues detected in chamnamul, spinach and perilla leaves (p < 0.05). There were also significant differences between monthly price and pesticide residues exceeding MRL in chamnamul and crown daisy (p < 0.05). Although the small number of leafy vegetables and short period were analyzed in this study, the consolidation monitor of pesticide residues according to the season and price will be needed to acquire the safety of agricultural products.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.279-287
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• 2017

BACKGROUND: Many farmers who cultivate the strawberries for export have used agricultural chemicals which MRL (Maximum Residue Limits) of main export target countries or simultaneous multi-residue analysis in Korea have not been established. Among them, the cyenopyrafen and cyflumetofen were selected and applied to this study to determine the PHI (pre-harvest interval) which is appropriate to the PLS (Positive List System) criterion (0.01 mg/kg) and to investigate the residual amounts in the samples. In addition, Fifty pesticides were monitored to check up whether it is suitable or not for main export target countries. METHODS AND RESULTS: Cyenopyrafen and cyflumetofen were spayed out to the strawberries. Samples for residual analyses were taken for maximum 60 days. After sampling, they were extracted by the QuEChERS method and analyzed using the LC-MS/MS. Cyenopyrafen and cyflumetofen were detected in a range of 0.0106~2.6517 mg/kg and of 0.0005~1.4480 mg/kg, respectively. From this results, they were found to be suitable for PLS concentration after 30 or 45 days after spray. In addition, they were detected in most samples that were selected at random. Their concentrations were higher than the PLS criterion in the maximum twenty samples. Twelve of pesticides unsuitable for main export target countries have been detected in the monitoring of simultaneous multi-residue analysis. The result indicates they are unsuitable for export since they excesses over PLS criterion. CONCLUSION: The monitoring result showed it is necessary to establish the pesticide standards of safe use suitable for the PLS criterion. In addition, it is considered continues management and inspection are needed to solve problems caused by unsuitable pesticides in export strawberries.