• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.247-263
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• 2016

Safe animal feed is important for the health of animals, the environment and for the safety of foods of animal origin. Therefore, the aims of this study were: 1) to validate simultaneous analytical method and 2) to investigate the amount of pesticide residues in animal feed from Republic of Korea as a part of official control. A total of 126 samples were collected in 2015 and analyzed for 105 pesticides. According to pesticides monitoring result, no residue was found in 84.1% of the samples, whereas 15.9% of samples contained pesticide residues below the maximum residue limits (MRLs). Pirimiphos-methyl and cyproconazole were the two most frequently found pesticides. The results show that all commercial feed monitored in 2015 were safe under the Korean MRL and occurrence of pesticide residues in animal feed could not be considered serious threats to human and animal health. However, continuous monitoring with tighter regulation for pesticide residues in animal feed is recommended.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.42-48
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• 2017

This study was conducted to compare the effect of bagging technique on the presence of pesticide residues in various parts of grape fruit (whole fruit, pulp and peel). The tested pesticides were diluted at 2,000 times and sprayed three times onto the crops at an interval of seven days and then they were collected at 0, 1, 3, 5 and 7 days after final application. Later, bagging/non-bagging samples were pre-treated with fruit, pulp and peel samples, respectively. Thiacloprid and lufenuron were not detected in any of the bagging samples. The thiacloprid residues of non-bagging samples in whole, peel and pulp samples were 0.47-1.09, 0.18-0.33 and 1.24-1.67 mg/kg, respectively. The lufenuron residues of non-bagging samples in whole fruit, peel and pulp samples were 0.16-0.62, < LOD-0.08 and 0.85-1.48 mg/kg, respectively. The biological half-lives of thiacloprid and lufenuron in whole fruit, peel and pulp of non-bagging samples were 5.7, 15.1 and 7.8 days and 4.0, 9.4 and 2.6 days, respectively. While the unbagged samples showed a sequential decrease in pesticide residues, this study concludes that bagging would be an effective method to protect the presence of thiacloprid and lufenuron residues in grape fruits.

• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.202-210
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• 2023

To analyze the pesticide residues in commercial bee pollen products in South Korea, 61 samples were collected and screened for 339 pesticides. Results revealed that approximately 34% (>LOQ) of samples were contaminated with at least one pesticide. The pesticide residue detection rates of domestic and imported samples were 31% and 44%, respectively. Furthermore, the pesticide residue detection rate of online distribution (60%) was higher than that of offline distribution (27%). Fifteen pesticides were discovered in bee pollen, and pendimethalin, chlorfenvinphos, chlorpyrifos, and fluazinam were detected in 7, 6, 3, and 2 order of frequency, respectively. Even though its concentration was low, chlorfenvinphos which is banned in food crops in the United States, European Union, and Korea, was detected in bee pollen samples commonly. Therefore, continuous investigation of pesticide residues in bee pollen products and their acceptance criteria is required for safety.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.570-574
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• 2013

This study was conducted to assess $N_2O$ emissions in agricultural soils of Korea under the 1996 IPCC (Intergovernmental Panel on Climate Change) methodology. $N_2O$ emissions in agricultural soils were calculated the sum of direct emission and indirect emission by the N sources and emissions by field burning of crop residues. $N_2O$ emission was highest in animal manure as 1,547 $CO_2$-eq Gg. Indirect emissions by atmospheric deposition and leaching and runoff were 1,463 and 1,753 $CO_2$-eq Gg, respectively. $N_2O$ emission by field burning of crop residues was highest in pepper due to the residue/crop ratio and field burning ratio.

• Korean Journal of Environmental Agriculture
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• v.22 no.3
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• pp.227-232
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• 2003

This study was conducted to evaluate the terminal residue of a new fungicide, KNF 1002, in cucumber and pepper under greenhouse and field conditions. When a microemulsion formulation (20%) of KNF 1002 was applied once or twice during $1{\sim}7$ days before harvest, its terminal residue in cucumber ranged <$0.02{\sim}0.20\;mg/kg$ under greenhouse condition. In pepper, its figure recorded $0.31{\sim}0.79\;mg/kg$ and $0.11{\sim}0.28\;mg/kg$ under greenhouse and field conditions, respectively. Much higher level of terminal residues was observed in leaves than those in fruits in pepper, showing $7.38{\sim}25.20\;mg/kg$ and $0.11{\sim}1.99\;mg/kg$ under greenhouse and field conditions, respectively. Cultivation condition affected evidently the residue level in pepper harvests. Residual pattern of KNF 1002 seemed to be comparable to strobilurin fungicides currently used.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.97-103
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• 2018

BACKGROUND: Dissipation of acetamiprid and thiamethoxam in greenhouse grown chard samples was evaluated at 5 intervals including the pre-harvest interval after application. This study was conducted to determine the residue levels, the biological half-lives and dissipation rate of acetamiprid and thiamethoxam in chard under controlled conditions. METHODS AND RESULTS: Acetamiprid and thiamethoxam were applied in accordance with good agricultural practices for chard. Chard samples were collected at 0, 1, 2, 3, 5, 7, 10 and 14 days after application. Quantitaion was performed by HPLC-DAD system with C18 column. Limit of quantification (LOQ) of acetamiprid and thiamethoxam were both 0.02 mg/kg for chard. The recovery of acetamiprid and thiamethoxam were 77.8~107.5% and 94.3~108.6% at two concentration levels. The half-lives of pesticide dissipation in chard for two fields were 11.9 and 8.2 days for acetamiprid and 3.6 and 3.3 days for thiamethoxam respectively. The dissipation rate of acetamiprid and thiamethoxam were estimated according to the statistics method with a 95% confidence. CONCLUSION: Dissipation of acetamiprid and thiamethoxam in chard were determined under greenhouse. The concentration of acetamiprid and thiamethoxam in chards at 0 days after application were below specified by Korean MRL. Dissipation rate constant will be useful to set the pre-harvest residue limit for public health and consumer protection.

• Carbon letters
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• v.26
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• pp.66-73
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• 2018

We assessed the effects of combining bio-char with straw residue mulching on the loss of soil soluble nutrients and citrus yield in sloping land. The two-year study showed that straw residue mulching (ST) and bio-char application combined with straw residue (ST+BC) can significantly reduce soil soluble nutrient loss when compared with the control treatment (CK). The comparative volume of the soil surface runoff after each of the treatments was as follows: CK > ST > ST + BC. Compared with the CK, the runoff volume of the ST was reduced by 13.6 % and 8.5 % in 2014 and 2015, respectively. Compared with the CK, combining bio-char with the ST application reduced the loss of soluble nitrogen and improved the soil total nitrogen content reaching a significant level in 2015. It dramatically increased the soil organic matter content over the two year period (36.3% in 2014, 50.6% in 2015) as well as the carbon/nitrogen ratio (C/N) (16.6% in 2014 and 39.3% in 2015). Straw mulching combined with bio-char showed a trend for increasing the citrus yield.

• BMB Reports
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• v.41 no.1
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• pp.41-47
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• 2008

Fe65 is characterized as an adaptor precursor (APP) through its PID2 element, as well as with the other members of the APP protein family. With the serum- and glucocorticoid-induced kinase 1 (SGK1) substrate specificity information, we found that the putative site of phosphorylation in Fe65 by SGK1 is present on its $Ser^{566}$ residue in $^{560}CRVRFLSFLA^{569}$(X60469). Thus, we demonstrated that Fe65 and the fluorescein-labeled Fe65 peptide $FITC-^{560}CRVRFLSFLA^{569}$ are phosphorylated in vitro by SGK1. Phosphorylation of the $Ser^{566}$ residue was also demonstrated using a $Ser^{566}$ phospho-specific antibody. The phospho Fe65 was found mainly in the nucleus, while Fe65 S556A mutant was localized primarily to the cytoplasm. Therefore, these data suggest that SGK1 phosphorylates the $Ser^{566}$ residue of Fe65 and that this phosphorylation promotes the migration of Fe65 to the nucleus of the cell.

• Current Research on Agriculture and Life Sciences
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• v.31 no.4
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• pp.272-279
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• 2013

The dissipation patters of the triazole fungicides flusilazole and myclobutanil in apples were investigated to establish the biological half-lives and pre-harvest residue limits (PHRLs). The residual amounts of the fungicides sprayed with single or triple doses were below the maximum residue limits (MRL) for apples established by Ministry of Food and Drug Safety. The dissipation constants of the fungicides in the apples were 0.0513 for flusilazole and 0.0244 for myclobutanil meaning their biological half-lives were calculated as 6.2-6.7 days for flusilazole and 13.3-24.8 days for myclobutanil. The PHRLs calculated using the dissipation constants indicated that the residual amounts of flusilazole and myclobutanil in the apples at the harvesting date would be below the MRLs if their residual amounts were 0.43 and 0.59 mg/kg, respectively, at 7 days prior to harvesting the apples.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.142-147
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• 2013

BACKGROUND: This study was conducted to monitor residual pesticides in domestic agricultural products and to assess their risk to human health. METHODS AND RESULTS: 123 samples containing both general and environment-friendly certified agricultural products were purchased from traditional domestic markets and supermarkets in six provinces of Korea. Multiresidue analyses of one hundred twenty-two pesticides except for herbicides were performed with gas chromatography-electron capture detector, gas chromatography-nitrogen/phosphorus detector, and high-performance liquid chromatography. Sixteen pesticides were detected in 45 agricultural product samples, which were 38 general, 6 low pesticide and 1 of GAP agricultural product samples and the detection rate was 33.6%. Pesticides detected in agricultural product samples were cypermethrin, lufenuron, fenvalerate, bifenthrin, chlorfenapyr and iprodione. Residual concentration of 18 samples were exceeded the recommended maximum residue limit set by Ministry of Food and Drug Safety and two kinds of unregistered pesticides in korea were also detected in two samples. CONCLUSION(S): In order to do risk assessment by agricultural products consumption, estimated daily intake of residual pesticides were determined and compared to acceptable daily intake, referring to %ADI values. The range of %ADI values was from 0.038% to 2.748%. Taken together, it demonstrates the pesticides found in agricultural products samples were below the safety margin, indicating no effect on human health.