• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.77-83
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• 2013

This study was performed to investigate pre-harvest residue limit (PHRL) in amaranth, to estimate biological half-life of emamectin benzoate and identify the characteristics of the residue. Pesticides of standard and double appplication rate, were sprayed once on amaranth at 0, 1, 2, 3, 5, 7, 10, 14 days before harvest. Amaranth sample was extracted with acetonitrile and partitioned with dichloromethane, and pesticide residues were determined with LC/MS/MS. The limit of detection of emamectin benzoate was 0.01 mg/kg. Recoveries of emamectin benzoate ($B_{1a}$, $B_{1b}$) at two fortification levels of 0.1 and 0.5 mg/kg, $B_{1a}$ were $93.3{\pm}0.7%$ and $93.2{\pm}7.7%$, $B_{1b}$ were $106.6{\pm}1.9%$ and $80.5{\pm}6.6%$, respectively. The biological half-lives of emamectin benzoate were about 2.0 days at standard application rate and 1.7 days at double application rate, respectively. The PHRL of emamectin benzoate were recommended as 0.84 mg/kg for 10 days before harvest.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.453-462
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• 2011

This study was carried out to survey the residual characteristics of pesticides and assess their safety. Nineteen agricultural commodities, collected from wholesale and traditional markets in Cheongju. Nineteen agricultural commodities including perilla leaves were collected from the markets on October 29th, 2010. Total 240 pesticides which can be analyzed by multiresidue analysis method by GLC and HPLC were monitored and the pesticides detected were confirmed by GC-MSD and LC-MS. Five pesticides, alachlor, bifenthrin, endosulfan, procymidone and triflumizole, were detected from five samples, such as welsh onion, leek and celery in case of wholesale market and perilla leaves and welsh onion in case of traditional market. Detection rate of 13.2% was obtained as a result of pesticide analysis but 2.6% of the pesticides detected exceeded their maximum residue limits. The estimated daily intakes (EDIs) and maximum permissible intakes (MPIs) of the pesticides detected were less than 26% and 0.05% of their acceptable daily intakes (ADIs) respectively, representing that residue levels of the pesticides detected would be safe.

• 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.13 no.1
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• pp.13-20
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• 2009

Two insecticides, commonly used for Chinese cabbage, etofenprox and methoxyfenozide, were subjected to a field residue trial to evaluate safeties of the residues at harvest. The pesticides were sprayed onto the crop at recommended and double doses 10 days before the prearranged harvest and then sampling was done at 0, 1, 2, 3, 5, 7, 10, and 12 days after spraying. The amounts of pesticides residues in the crop were analyzed by chromatographic methods. Limits of detection (LODs) of both etofenprox and methoxyfenozide were $0.01mg\;kg^{-1}$ and mean recoveries were $96.76{\pm}2.67$ (CV=2.76%) and $95.84{\pm}2.57%$(CV=2.69%) in case of etofenprox and $103.26{\pm}3.21$ (CV=3.11%) and $94.50{\pm}1.35%$(CV=1.43%) in case of methoxyfenozide, respectively. Biological half-lives of etofenprox and methoxyfenozide were 3.2 and 3.5 days at the recommended dose and 2.7 and 3.5 days at the double dose, respectively. Initial residue levels of the pesticides at the recommended and double doses exceeded their MRLs, but final residue levels of the pesticides in the crop samples at harvest were less than their MRLs. The ratios of the EDI to ADI by intake the crop harvested 10 days after spraying were less than 4% of their ADIs, representing that residue levels of two pesticides at harvest were evaluated as safe.

• The Korean Journal of Pesticide Science
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• v.8 no.2
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• pp.112-116
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• 2004

Two experiments were carried out in greenhouse under hydrophilic culture facilities and simulation model to provide residual characteristics of ethoprophos treated in sweet pepper's growth. To identify the pattern of absorption-translocation through the plant roots, ethoph 5 % GR were diluted in hydrophilic culture solution and drenched at a time per day for three days. The residue in fruit came closed to 0.02 ppm of MRL at 10 days after treatment(DAT) and reached peaked 0.06 ppm at 30 DAT and remained excess MRL level until around 40 DAT. To confirm the pattern of contamination by volatilization of ethoprophos, ethoph 5%GR was scattered 2 g per cubic meter. At 72 hours after treatment, the residue in sweet pepper fruit was exceed the MRL and the maximum residual amount were 0.62 ppm by volatilization. Consequently the use of ethoprophos during the growth of sweet pepper would be strong possibility to exceed the MRL.

• The Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.341-348
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• 2016

Residual patterns of fungicides fludioxonil and metconazole applied 2 or 3 times on wheat were investigated with consideration for their distribution rates in each compartment of wheat. Wheat samples collected at harvesting day were divided into three compartments such as grain, hull and straw, and the pesticide residue analysis was individually carried out to such compartments of wheat. The analytical methods of fungicide residues in wheat were acceptable, with recoveries of 84.3 to 113.3% and correlation coefficients of 0.1 to 4.7%. Due to the systemic characteristics, the residual amounts of metconazole in the grain part of wheat were greater as 0.13~0.17 mg/kg than those amounts (0.01-0.03 mg/kg) for fludioxonil. To absolute residue amounts of the fungicides in one wheat plant, their distribution rates in each compartment of wheat were the highest in straws (68.5-70.7%), followed by hulls (29.0-31.0%) and grains (0.2-0.8%).

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.361-369
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• 2015

This study investigated residual characteristics of bistrifluron and fluopicolide in Korean cabbage, and suggested the pre-harvest residue limits (PHRLs) based on their dissipation patterns and biological half-lives. The pesticides were sprayed on Korean cabbage in two different region under greenhouse conditions at the recommended dose, respectively. The samples for residue analysis were harvested at 0 (2 hr), 1, 2, 4, 6, 8 and 10 days after treatment, and analyzed by HPLC after clean-up with Florisil SPE. The limit of quantification (LOQ) was $0.03mg\;kg^{-1}$ for bistrifluron and fluopicolide, and the recoveries ranged from 87.2-110.6% with below 5% of RSD. The biological half-lives of field I and field II were 3.9 and 4.2 days for bistrifluron and 4.9 and 4.2 days for fluopicolide, respectively. The PHRL of bistrifluron and fluopicolide were recommended as 3.83 and $3.23mg\;kg^{-1}$ for 10 days before harvest, respectively.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.1-9
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• 2010

In order to survey residual characteristics of pesticides in the agricultural products selling at markets and to assess their safety, a total of 120 agricultural products were collected from the wholesale and traditional markets in Cheongju and analyzed the pesticide residues in them by multiresidue analysis method using GLC, HPLC and GC-MSD. Three pesticides, procymidone, penconazole, and tetraconazole, were detected from 4 samples such as onion, leek, tomato, and green pepper. Fungicide penconazole was detected from the onion collected from wholesale market. Fungicide procymidone was detected from leek and tomato and fungicide tetraconazole was detected from green pepper. Pesticide residues were detected from 3.3% of the total samples. The estimated daily intakes (EDIs) of the pesticides detected were less than 0.1% of their acceptable daily intakes (ADIs), representing that residue levels of the pesticides detected were evaluated as safe.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.375-381
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• 2018

This study was performed to investigate the residual characteristics of the insecticide dinotefuran in asparagus under greenhouse conditions from July to August and consequentially to obtain basic data for guidelines on the safe use of this pesticide in asparagus. Residues of dinotefuran in young stem of asparagus before and after growing mother stem were analyzed from samples collected at 0, 1, 3, 5, and 7 days after single application of a commercial formulation of dinotefuran (wettable powder, 10%) at the recommended dose (2,000 times dilution). The residue of dinotefuran in young stem of asparagus was analyzed by HPLC-UVD, and recovery of dinotefuran in young stem was tested at 0.5 and 1.0 mg/kg concentrations. As a result, the limit of quantitation (LOQ) of dinotefuran was 0.01 mg/kg, and the recovery of dinotefuran was in the range of 83.3-94.0% with a coefficient of variation less than 10%. Residues of dinotefuran in young stem of asparagus before and after growing the mother stem were lower than the tentative limit (0.05 mg/kg) from 5 and 3 days after single application, respectively. Based on these results, single application of dinotefuran (wettable powder, 10%) at the recommended dose at 7 days before harvest would have no deleterious effects on safety issues concerning pesticide residue. This result might provide basic information to construct guidelines for the safe use of dinotefuran in asparagus.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.131-136
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• 2012

This study was carried out to elucidate residual characteristics of azoxystrobin and difenoconazole in fresh ginseng. Test pesticides were sprayed onto ginseng both in 2009 for 3-year-old ginseng and in 2010 for 4-year-old ginseng according to their pre-harvest intervals (PHIs). Limit of quantitation (LOQ) of both azoxystrobin and difenoconazole was 0.003 mg/kg. Analytical methods set up for the test pesticides were considered to be suitable for the analysis of their residues in fresh ginseng, considering that their recoveries ranged from 87.58 to 112.79%. Concentration of azoxystrobin in 3-year-old ginseng ranged from 0.004 to 0.011 mg/kg and that in 4-year-old ginseng ranged from 0.007 to 0.016 mg/kg. Amounts of difenoconazole in 3- and 4-year-old ginsengs were from 0.003 to 0.007 and from 0.007 to 0.01 mg/kg, respectively, representing no accumulation effect observed in residue amount between them.