• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.297-304
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• 1994

This study was carried out to develop bioassay for detection of pesticide residues in agricultural products by using the soil microbial isolates sensitive to pesticides. One hundred bacterial isolates and eighty five fungal isolates were obtained from soil and their sensitivity to 10 ppm of several pesticides was examined in vitro. Five bacterial isolates and three fungal isolates were found sensitive to organochloride fungicide and two fungal isolates sensitive to organocopper fungicide. Among these isolates, B46, B93 and F67 were tested to find out the difference in sensitivity according to the methods of fungicide treatment. All of the isolates were found sensitive to 10 ppm of organochloride fungicides mixed directly in PDA. But they were found insensitive to the fungicide mixed in PDA after filtering through membrane filter. In case of organocopper fungicide, the isolates were found sensitive only when it was treated in PDA. And their sensitivity showed difference among various kinds of organochloride fungicides. B46 and B93 were employed to check the possibility as the agent for detection of the pesticidal residues in twenty eight agricultural products including rice. It was found that all samples had not residues because the samples did not inhibit the growth of isolates. When organochloride fungicides were applied to the above products, it was possible to detect the residues in fruits and vegetables at the concentration of 10 ppm, but not in starch-rich grains. B46 and B93 were identified as Bacillus sp. according to their bacterial characteristics in culture.

• Journal of Biosystems Engineering
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• v.31 no.6 s.119
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• pp.535-540
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• 2006

For a biosensor development, an enzyme-linked immunosorbent assay (ELISA) of the fungicide iprovalicarb was developed by minimizing the processing time. The time for whole incubation process was reduced from 135 minutes to 15 minutes. The concentration of antibody was varied to improve sensitivity. The total processing time was reduced from 2.5 hours to 20 minutes, the final sensitivity ($IC_{50}$ value) of 7.93 ng/mL and the lowest detection limit of 0.045 ng/mL were obtained. This ELISA was applied to potatoes and onions, and the recoveries were in the range of 98.85 $\sim$ 101.20% and 87.97 $\sim$ 102.70%, respectively. Accordingly, this method can be used as basis for a biosensor for rapid monitoring of iprovalicarb residues in crops.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2000.11a
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• pp.160-160
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• 2000

• Korean Journal of Environmental Agriculture
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• v.39 no.2
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• pp.130-137
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• 2020

BACKGROUND: Mefentrifluconazole and triticonazole are the triazole fungicides. The maximum residue levels for agricultural products need to be set up. Therefore, development of the official analytical method for determination of mefentrifluconazole and triticonazole residues from agricultural crops was necessary due to safety management, and then a simultaneous analytical method was developed for the determination of mefentrifluconazole and triticonazole in agricultural crops. METHODS AND RESULTS: Samples were extracted using acetonitrile and purified using dispersive solid phase extraction, and then detected with liquid chromatograph-tandem mass spectrometry (LC-MS/MS). Matrix-matched calibration curves (0.0025-0.25 ㎍/mL) were linear into a sample extract with r²>0.99. For validation, the recovery test was carried out at three fortification levels (LOQ, 10 LOQ and 50 LOQ) from agricultural samples. The results for mefentrifluconazole and triticonazole ranged between 92.3 to 115.3% and 91.4 to 108.5%, respectively and RSD (relative standard deviation) values were also below 6.0%. Furthermore, inter-laboratory was conducted to validate the method. CONCLUSION: All values were corresponded with the criteria ranges requested by both the CODEX (CAC/GL 40-1993, 2003) and MFDS guidelines (2016). Therefore, the proposed method can be used as an official analytical method for determination of mefentrifluconazole and triticonazole (triazole fungicides) in the Republic of Korea.

• 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.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.13-19
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• 2013

Isopyrazam, a new pyrazolecarboxamide fungicide developed by Syngenta, was highly active against foliar powdery mildew pathogens on cucumber, oriental melon and various vegetables. Following foliar applications on cucumber and oriental melon, crop residues were determined using high performance liquid chromatography. For all studies, limit of quantification was 0.02 mg/kg and minimum detection level was 2.0 ng and recoveries were 83.0-88.0% on cucumber, 92.4-104.5% on oriental melon. Isopyrazam was detected 0.07-0.72 mg/kg on cucumber and < 0.02-0.68 mg/kg on oriental melon, respectively. The TMDI (Theoretical Maximum Dailly Intake) of isopyrazam on cucumber and oriental melon was estimated to less than 1.765% of ADI.

• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.50-56
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• 2009

Surface plasmon resonance (SPR) biosensor has been used to detect many biochemical reactions, because this label-free sensor has high sensitivity and rapid response. The reactions are monitored by refractive index changes of the SPR biosensor. Iprovalicarb is protective, curative, and eradicative systemic fungicide introduced by Bayer AG in 1999. It has potential far control of downy mildew infesting onion, cucumber, grape and melon, late blight infesting tomato and potato, and anthracnose infesting watermelon and pepper. It is strictly limited to the maximum residue limit. In this study, the applicability of a portable SPR biosensor (Spreeta, Texas instrument, TX, USA) to detect the iprovalicarb residue was examined. The sensor chip was adopted to detect the reaction of iprovalicarb to immobilized iprovalicarb-antibody. The binding of the iprovalicarb onto the biosensor surface was measured by change of the refractive index (RI). Characteristics of the sensor chip including specificity, sensitivity, stability, and reusability were analyzed. In calibration test for seven levels of iprovalicarb concentration (0.32 to 5,000 mg/L) with three replications, a Sigmoidal model with Hill function was obtained between relative RI value and the iprovalicarb concentration with R-square of 0.998. It took 30 minutes to complete a set of detecting assay with the SPR biosensor.

• Analytical Science and Technology
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• v.27 no.3
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• pp.172-180
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• 2014

Fenpyrazamine which is a pyrazole fungicide class for controlling gray mold, sclerotinia rot, and Monilinia in grapevines, stone fruit trees, and vegetables has been registered in republic of Korea in 2013 and the maximum residue limits of fenpyrazamine is set to grape, peach, and mandarin as 5.0, 2.0, and 2.0 mg/kg, respectively. Very reliable and sensitive analytical method for determination of fenpyrazamine residues is required for ensuring the food safety in agricultural products. Fenpyrazamine residues in samples were extracted with acetonitrile, partitioned with dichloromethane, and then purified with silica-SPE cartridge and eluted with hexane and acetone mixture. The purified samples were determined by HPLC-UVD and confirmed with LC-MS and quantified using external standard method. Linear range of fenpyrazamine was between $0.1{\sim}5.0{\mu}g/mL$ with the correlation coefficient (r) 0.999. The average recovery ranged from 71.8 to 102.7% at the spiked level of 0.05, 0.5, and 5.0 mg/kg, while the relative standard deviation was between 0.1 and 7.3%. In addition, limit of detection and limit of quantitation were 0.01 and 0.05 mg/L, respectively. The results revealed that the developed and validated analytical method is possible for fenpyrazamine determination in agricultural product samples and will be used as an official analytical method.

• Journal of Biosystems Engineering
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• v.32 no.6
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• pp.440-447
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• 2007

In this study, a biosensor was developed using an enzyme-linked immunosorbent assay (ELISA) to rapidly measure the fungicide iprovalicarb residues in agricultural products. The biosensor was designed to include micro-pumps and solenoid valves for fluid transport, a spectrophotometer cuvet as a reaction chamber, a photodiode with a light-emitting diode for optical density measurement, and a control microcomputer to implement assay. The rate of change in optical density of the cuvet was read as final signal output. Micro-pumps were evaluated to investigate their delivery capability, the highest values of the error and the coefficient of variation were 4.3% and 4.6% respectively. As the incubation period was reduced from 15 minutes to 11 minutes to shorten the total processing time, the sensor sensitivity was decreased as the antibody dilution ratio was reduced to a half. The maximum usable period of the coated cuvet was found to be two days with 1% error limit. To predict the concentration of the iprovalicarb residue in agricultural products, a linear calibration model was obtained with r-square values of 0.992 for potato and 0.985 for onion. In validation test for the samples of potatoes and onions against the high performance liquid chromatography, very high correlation values were obtained as 0.996 and 0.993 respectively. Using the cuvet immobilized with antigen, it took 21-minutes for the biosensor to complete the measuring process of the iprovalicarb residues.

• Korean Journal of Environmental Agriculture
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• v.41 no.1
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• pp.1-8
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• 2022

BACKGROUND: The pesticide residue in rotational crop is one of the main concerns to agricultural products because it has the potentiality of violating positive list system (PLS). Thus, the crops used for the rotational cultivation should be considered the pesticide residue patterns to meet the PLS guideline. In this study, we evaluated the residue patterns of fungicide azoxystrobin in radish based on plant back interval (PBI) experiment. METHODS AND RESULTS: Azoxystrobin was treated onto greenhouse soil at 217 g a.i./10a in two different regions. Radishes were sown onto the soil 30 and 60 days after azoxystrobin treatment. The soil and plant samples were subjected to a modified QuEChERS method and LC/MS/MS analyses to determine the residues of azoxystrobin. The methods were validated to meet the guidelines of the pesticide residue analysis recommended by the Rural Development Administration, Republic of Korea. Azoxystrobin was dissipated significantly in soil during the experimental period and found as a level less than 0.01 mg/kg in radish 30 and 60 days after treatment. Azoxystrobin residues in radish samples were lower than the maximum residue limit (MRL) for root vegetables. CONCLUSION(S): This study suggests 30 days as a PBI for rotational cultivation of radish in greenhouse soil that had been treated with azoxystrobin at a level of 217 g a.i./10a.