• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.153-157
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• 2022

BACKGROUND: The residue dissipation pattern of pesticides for agricultural products during the pre-harvest period after the final application is important to prevent the maximum residue limit (MRL) violations in domestic and export markets. The MRL violations of carbendazim are observed more often in chamnamul by pesticide residue management surveys by the Ministry of Food and Drug Safety. The residue level at the pre-harvest interval (PHI) and the residue dissipation constant from the critical good agricultural practice (cGAP) trials could be estimated to meet the MRL and pose a health risk to consumers. METHODS AND RESULTS: Chamnamuls were harvested at 0, 1, 3, 5, 7, 10, and 14 days after application of carbendazim in accordance with critical GAP. The residue analysis in chamnanul was performed by HPLC-DAD with the C₁₈ column. The limit of quantitation of carbendazim was 0.04 mg/kg, and the recoveries were 74.4 - 95.8% at the two spiked levels (LOQ and 10LOQ) of carbendazim. The dissipation rates in chamnamul were calculated from the residues at the sampling days by statistical method at a 95% confidence level. The biological half-lives of residual carbendazim in the field trials 1 and 2 were 4.9 and 4.4 days, respectively. CONCLUSION(S): In this dissipation study, the residue concentrations at the recommended PHI were higher than the established MRL in Korea. Therefore, the MRL is proposed based on the residue data sets from the trials conducted at the same cGAP and the dietary exposure assessment.

• Journal of fish pathology
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• v.35 no.1
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• pp.93-102
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• 2022

This study performed a trichlorfon (TCF) residue and pharmacokinetic analysis with Japanese eels, Anguilla japonica, to obtain baseline data to establish the maximum residue level (MRL) of TCF in A. japonica. After dipping A. japonica in 30 ppm and 150 ppm of TCF at 28℃ and 18℃, drug residue in the body was analyzed with LC-MS/MS, and these results were further analyzed with the PK solver program to obtain the pharmacokinetic parameters of TCF in the serum, muscles, and liver. The maximum concentrations (C_max) in the serum, muscles, and liver were 25.87-357.42, 129.91-1043.73, and 40.47-375.20, respectively, and the time to maximum concentration (T_max) was 0.13-1.32h, 1.17-3.34h, and 0.14-5.40h, respectively. The terminal elimination half-life (T_1/2) was 2.13-3.92h, 5.30-10.35h, and 0.65-13.81h, respectively. In the 30 mg/L concentration group, TCF was not detected in the serum of eels 96 hours after bathing, and was below the detection limit after 336 hours in muscle and liver. On the other hand, in the 150 mg/L concentration group, TCF was not detected in the serum of eels 336 hours after bathing, but was detected in muscle and liver at 336 hours. In conclusion, the results of this study would be useful in establishing the MRL of TCF in farmed A. japonica.

• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.355-364
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• 2022

BACKGROUND: Pre-harvest interval and decline pattern of thiamethoxam were determined in kiwifruit using liquid chromatography-tandem mass spectrometry (LCMS/MS). The study was carried out to propose import tolerance using OECD maximum residue limit (MRL) calculator for the export promotion of kiwifruit to Taiwan. METHODS AND RESULTS: The thiamethoxam residue in kiwifruit was determined by using the LC-TriQ-MS/MS with the analytical process to set up the import tolerance under greenhouse conditions for Taiwan. Excellent linearity was observed for all of the analytes with a determination coefficient (R²)≥0.99. The limit of quantification was determined to be 0.01 mg/kg for both thiamethoxam and clothianidin in kiwifruit. Linearity was determined from the co-efficient of determinants (R²) obtained from the seven-point calibration curve. The standard calibration curve showed as follows; 1) Site 1 (Gimje): y = 944,406X + 1,583 (R²=0.9995), 2) Site 2 (Goheung): y = 1,356,205X + 934 (R²=0.9983), and 3) Site 3 (Jangheung): y = 1,239,937X - 3,090 (R²=0.9908). The residue of thiamethoxam in the kiwifruit for three decline trials showed the range of 0.35 to 0.56 mg/kg in site 1 (Gimje), 0.24 to 0.55 mg/kg in site 2 (Goheung), and 0.28 to 0.42 mg/kg in site 3 (Jangheung), respectively. However, clothianidin was not detected in all of the treatments. The maximum residual amounts (decline) in the samples, sprayed according to the safe-use standard for thiamethoxam 10% WG in kiwifruit (30 days before harvest, 3 sprays every 7 days) were 0.56 mg/kg in site 1, 0.55 mg/kg in site 2, and 0.42 mg/kg in site 3, respectively. CONCLUSION(S): The import tolerance (IT) of thiamethoxam for kiwifruit may be proposed to be 0.9 mg/kg by using the OECD MRL calculator.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.184-192
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• 2017

BACKGROUND: This study was performed to evaluate the residue dissipation of boscalid and spinetoram on crown daisy and sweet pepper affected by the morphology of the crop. The half-lives and dissipation rate constants for boscalid and spinetoram on crown daisy and sweet pepper were calculated. And then lower limit of 95% confidence interval for dissipation rate constant could be used to propose the pre-harvest residue limit. METHODS AND RESULTS: The pesticide products diluted according to the pesticide label were applied one time on crown daisy and sweet pepper at 2 field sites, respectively. Initial concentration of boscalid and spinetoram on crown daisy after application were in the range of 72.80~117.15 mg/kg and 2.82~4.67 mg/kg, respectively. And Initial concentration of boscalid and spinetoram on sweet pepper were in the range of 1.58~1.62 mg/kg and 0.10~0.21 mg/kg, respectively. Boscalid and spinetoram for crown daisy dissipted below the maximum residue limit(MRL) at 10 and 2 days after application, respectively. All residues concentration of boscalid and spinetoram for sweet pepper below the MRL at 0 day after application. The half-lives based on dissipation rate constant for boscalid and spinetoram on crown daisy were 4.2~4.9 days and 3.0~2.4 days respectively. And the half-lives for boscalid and spinetoram on sweet pepper were 6.7~7.0 days and 2.8~4.0 days respectively. CONCLUSION: The difference in initial concentration of boscalid and spinetoram among crop commodities were due to different crop morphology with larger surface areas. This study was suggested that pre-harvest residue limit would be calculated from lower limit of 95% confidence interval for dissipation rate constant and would be useful to protect consumers by controlling the pesticide residues in crop.

• Korean Journal of Medicinal Crop Science
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• v.16 no.6
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• pp.390-396
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• 2008

The aim of this work is to assess the safety of fungicide tolclofos-methyl, difenoconazole and azoxystrobin in ginseng sprayed by safe use guideline. When tolclofos-methyl was sprayed on ginseng by safe use guideline, the residue amounts (MRL) of it in ginseng was 0.13 mg/kg which is below than 0.3 mg/kg, maximum residue limit established by Korea Food & Drug Administration (KFDA). The residue amounts of ginseng parts, head part was 0.37 mg/kg and main body part was 0.13 mg/kg. In case of difenoconazole, the residue amounts in ginseng was 0.81 mg/kg. which was exceed the MRL, 0.2 mg/kg. By the analyze results of ginseng part, the residues of head and main body part were 3.01 and 0.40 mg/kg, respectively. In experiment of vinyl mulching, the residue amount of difenoconazole in ginseng was 0.05 mg/kg. The residue amounts of azoxystrobin in ginseng sprayed by safe use guideline was 0.14 mg/kg. This residue was not exceed the MRL 0.5 mg/kg. The residue amounts by ginseng parts was 0.51 mg/kg for head part and 0.28 mg/kg for main body part. In case of vinyl mulching, the residue amount of azoxystrobin was 0.02 mg/kg.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.308-314
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• 2012

In order to monitor the residual pesticides in environment friendly agricultural commodities, fruits and fruiting vegetables. Twenty-five agricultural commodities were collected twice in May and August 2011 from nine environment friendly agricultural commodities-selling supermarkets and retail stores located in eight major cities in Korea. The number of each agricultural commodity collected, 555 samples in total, was 152 organic agricultural products, 202 pesticide-free agricultural products and 201 low-pesticide agricultural products. Pesticide residues in samples were analyzed by multiresidue method for 245 pesticides using a GC-ECD/NPD and an HPLC-DAD/FLD and the peaks suspected as pesticides were identified with a GC/MSD. As a result of pesticide residue analysis, three pesticides, bifenthrin, EPN and chlorpyrifos, were detected from four samples including apple, representing a detection rate of 0.72%. The residue levels of the four pesticide-detected samples were less than their maximum residue limits (MRLs) but one pesticide EPN detected from pear exceeded its legible criterion of one twentieth MRL. Estimated daily intakes of the pesticides detected from fruits and fruiting vegetables were less than 0.76% of their maximum permissible intake.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.421-430
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• 2019

In this study, 195 pesticide residues in fruit samples (n=150) at local markets in Chungcheongnam-do Chungnam, Korea were monitored using a multi-residue method combined with GC-MS/MS and LCMS/MS. Among 150 fruit samples, 40 types of pesticides were detected in 63 samples and the detection rate was 42.0%. However, the amounts were below the maximum residue limit (MRL). Detection rates for pesticides in each thpe of fruit were as follows ; citrus fruits (55.2%), pome fruits (41.3%), berries (38.7%) and stone fruits (36.0%). Although the sample size was small (n=2), pesticide residues were not detected in tropical fruits. Occurrences of detection of pesticide residues in apple showed the highest level, and mainly, insecticides were detected most frequently. The most commonly detected pesticides residues were bifenthrin (21), pyraclostrobin (17), novaluron (13), boscalid (10), chlorfenapyr (9), trifloxystrobin (9), furathiocarb (9), acetamiprid (8) and chlorpyrifos (8). Five types of residual pesticides (bifenthrin, chlorfenapyr, deltamethrin, fenpropathrin and fenvalerate) were detected in quince, and out of these five, fenpropathrin exceeded the MRL based on the Positive List System (PLS). These results suggested that pesticide residues in fruit samples should be continuously monitored, although residue levels in 63 other fruit samples were evaluated as being within a safe level.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.412-418
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• 2009

This study is conducted in order to know the residue patterns of insecticide cypermethrin and fungicide diethofencarb in ginseng sprayed by various application methods. Two pesticides were sprayed separately on ginseng using traditional, soil and vinyl mulching applications. The vinyl mulching application was that head part of ginseng protected from pesticides. When cypermethrin was sprayed on ginseng by traditional application, its residue amount in ginseng was 0.25 mg/kg which exceeded 0.1 mg/kg, maximum residue limit(MRL) established by Korea Food & Drug Administration(KFDA). But in case of vinyl mulching and soil application, its residue amounts were 0.04 and 0.07 mg/kg, respectively. The residue amount of diethofencarb in ginseng was 3.01 mg/kg which exceeded the MRL, 0.3 mg/kg. Further, in case of vinyl mulching and soil application, its residue amounts were 1.71 and 9.39 mg/kg which exceeded the MRL 0.3 mg/kg. Although the residue amounts of both pesticides exceeded the MRLs for ginseng, we can explain that pesticides remained in head part of ginseng is probably the reason why higher pesticides residue levels were observed.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.34-43
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• 2001

For 202 pesticides with maximum residue limit(MRL) in Korea, anticipated problems were identified and remedial actions were suggested. The risk index expressed as the ratio of theoretical maximum daily intake against ADI which exceeds 80% appeared in 35 pesticides. Items showing 10-fold difference between Korea and Codex MRLs appeared in 35 pesticides and 47 food commodities. In any of the 202 pesticides, nominated crops without MRL were 33 items whereas non-nominated crops with MRL were 50 items. Under the Codex system, cases of separate MRLs among raw materials and processed products were exampled. Remedial actions to minimize the above-mentioned discrepancies were suggested respectively.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.248-254
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• 2012

BACKGROUND: In order to elucidate residual characteristics of difenoconazole and thiamethoxam by treatment to sweet persimmons for one year and to generate the data for the maximum residue limit (MRL) establishment for those pesticides in or on sweet persimmon. METHODS AND RESULTS: Systemic fungicide difenoconazole WP (10% a.i.) and systemic insecticide thiamethoxam WG (10% a.i.) were sprayed onto 12~25-years-old sweet persimmons according to its preharvest interval (PHI), respectively, and then fresh sweet persimmons were harvested at 0, 1, 3, 7, 14, 21 days after treatment from pesticide-sprayed plots at each 3 sites. The analytical methods were evaluated to limit of quantification, linearity, specificity, reproducibility and recoveries. The crop samples were extracted with acetone and performed dichloromethane partition process. The extracted samples of difenoconazole were analyzed by GC-ECD and the thiamethoxam extracted samples were analyzed by HPLC with good sensitivity and selectivity of the method. The average recoveries of difenoconazole ranged from 87.5 to 99.5% with the percentage of coefficient variation in the range 4.1~7.6% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg). And the average recoveries of thiamethoxam and clothianidin ranged from 88.8 to 98.9% and 83.2 to 96.6% with the percentage of coefficient variation in the range 3.6~5.0% and 3.8~9.4% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg), respectively. The residue amounts ranges of difenoconazole were 0.2~0.56 mg/kg and the residue amount was decreased below the MRL level, 1.0 mg/kg, after 1 day harvest. The residue amounts ranges of thiamethoxam were 0.08~0.28 mg/kg and the residue amount was decreased below the MRL level, 0.5 mg/kg, after 1 day harvest. And the residue amount of clothianidin was below then 0.03 mg/kg for only one test site of 14 and 28 day samples. CONCLUSION: As a result, the residual amounts of difenoconazole and thiamethoxam were not exceeded the MRL of established criteria for sweet persimmon. The biological half-lives of difenoconazole and thiamethoxam were 13.6, 19.4, 16.3 and 10.0, 15.3, 14.0 days at each three test sites, respectively.