• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.214-223
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• 2013

BACKGROUND: This study focused on the development of an analytical method about dichlorprop (DCPP; 2-(2,4-dichlorophenoxy)propionic acid) which is a plant growth regulator, a synthetic auxin for agricultural commodities. DCPP prevents falling of fruits during their growth periods. However, the overdose of DCPP caused the unwanted maturing time and reduce the safe storage period. If we take fruits with exceeding maximum residue limits, it could be harmful. Therefore, this study presented the analytical method of DCPP in agricultural commodities for the nation-wide pesticide residues monitoring program of the Ministry of Food and Drug Safety. METHODS AND RESULTS: We adopted the analytical method for DCPP in agricultural commodities by gas chromatograph in cooperated with Electron Capture Detector(ECD). Sample extraction and purification by ion-associated partition method were applied, then quantitation was done by GC/ECD with DB-17, a moderate polarity column under the temperature-rising condition with nitrogen as a carrier gas and split-less mode. Standard calibration curve presented linearity with the correlation coefficient ($r^2$) > 0.9998, analysed from 0.1 to 2.0 mg/L concentration. Limit of quantitation in agricultural commodities represents 0.05 mg/kg, and average recoveries ranged from 78.8 to 102.2%. The repeatability of measurements expressed as coefficient of variation (CV %) was less than 9.5% in 0.05, 0.10, and 0.50 mg/kg. CONCLUSION(S): Our newly improved analytical method for DCPP residues in agricultural commodities was applicable to the nation-wide pesticide residues monitoring program with the acceptable level of sensitivity, repeatability and reproducibility.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.5-13
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• 2015

A chromatographic method for the determination of imazapyr, a non-selective herbicide, in agricultural commodities was developed to use safety control of pesticide residue on crops, and was fully validated as an official method for residue analysis. Agricultural commodities, mandarin (fruit), hulled rice (cereal grains), pepper (vegetables), potato (potatoes) and soybean (beans) were extracted with methanol and partitioned with dichloromethane to remove the interference obtained from sample extracts, adjusting pH to 2.5 by 4N hydrochloric acid. Finally, they were analyzed by high performance liquid chromatography coupled to UV detector (HPLC-UVD). The developed method had the linearity in the range of test concentrations with coefficients of determination ($r^2$) more than 0.99. Recovery studies were carried out at three concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. Recoveries were ranged between 72.1 to 108.0%, with relative standard deviations less than 10%. A consistent recovery was determined according to the CODEX guidelines (CAC/GL40, 2003). Finally, LC/MS with selected ion monitoring was also applied to confirm the suspected residues of imazapyr in agricultural samples. This developed method for determination of imazapyr residues in agricultural commodities. can be used as an official method.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.339-346
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• 2018

Cyanazine is a member of the triazine family of herbicides. Cyanazine is used as a pre- and post-emergence herbicide for the control of annual grasses and broadleaf weeds. This experiment was conducted to establish a determination method for cyanazine, as domestic unregistered pesticide, residue in major agricultural commodities using HPLC-DAD/MS. Cyanazine was extracted with acetone from representative samples of five raw products which comprised apple, green pepper, Kimchi cabbage, hulled rice and soybean. The extract was diluted with saline water and partitioned to dichloromethane for remove polar extractive in the aqueous phase. For the hulled rice and soybean samples, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized florisil column chromatography. On a $C_{18}$ column in HPLC, cyanazine was successfully separated from co-extractives of sample, and sensitively quantitated by diode array detection at 220 nm. Accuracy and precision of the proposed method was validated by the recovery experiment on every major agricultural commodity samples fortified with cyanazine at 3 concentration levels per agricultural commodity in each triplication. Mean recoveries were ranged from 83.6 to 93.3% in five major representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation(LOQ) of cyanazine was 0.02 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring(SIM) technique was also provided to clearly identify the suspected residue.

• Food Science and Preservation
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• v.8 no.3
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• pp.291-295
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• 2001

Photostimulated luminescence (PSL) analysis was applied to determine whether some agricultural commodities of Korean and Chinese origins have been irradiated or not. Cereals (brown rice and buckwheat) and legumes (soybean, peanut, fed bean and mung bean) were exposed to gamma irradiation at 0.5 ∼4 kGy The Korean garlic was irradiated at 0.05 ∼0.5 kGy. Cereals and mung bean were tool applicable to the PSL measurement, showing the intermediate values between the lower (700 photon counts, negative) and the upper threshold values (5,000, positive), however PSL values determined for soybean, peanut, red bean and garlic were suitable for being discriminated between nonirradiated and irradiated samples. There was no significant difference in PSL properties accgrding to the sample origins.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.619-634
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• 2019

In the field of traceability systems, researchers focus on applications in the agricultural food traceability and scanning commodities. The purposes of this paper, however, is to propose an efficient and reliable traceability system that can be applied to all kinds of commodities. Currently, most traceability systems store data in a central server, which is unreliable when the system is under attack or if the administrator tampers with the data for personal interests. Therefore, it is necessary to design a system that can eliminate these threats. In this paper, we propose a decentralized and non-reversible traceability system for storing commodity data. This system depends on blockchain technology, which organizes data in the form of chains without a central server. This chain-style storage mechanism can prevent malicious modifications. In addition, some strategies are adopted to reduce the storage pressure and response time when the system has stored all kinds of commodity data.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.185-194
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• 2015

This study was performed to establish a single residue analytical method for determining fungicide carpropamid residues in various agricultural commodities. Korean cabbage, apple, brown rice and green pepper were selected as representative crops. Samples were homogenized, extracted with acetone and purified by liquid-liquid partition and Florisil column chromatography. Carpropamid residues were analyzed at 220 nm with reversed phase HPLC equipped octylsilyl and octadecylsilyl column and confirmed using mass spectrometry. ILOQ (Instrumental limit of quantitation) of carpropamid was 2 ng and MLOQ (Method LOQ) was 0.02 mg/kg. Mean recoveries from four kinds of crop samples fortified at three levels (MLOQ, 10LOQ, 100LOQ) in triplicate were in the range of 84~112%. Relative standard deviations of the analytical method were all less than 10%, irrespective of crop types.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.23-30
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• 2018

The purpose of this research was to introduce network analysis method for analyzing pesticide residues in incongruity commercial agricultural commodities. Based on the "results in pesticide residues on incongruity commercial agricultural commodities" on "Guidelines for food safety management 2017", we used centrality analysis for pesticide residues via degree, closeness and betweenness centrality measurement. In case of degree centrality result, chlorpyrifos and diazinon were the most highly "connected node" in pesticide network. For the closeness centrality result, the most pesticides showed the similar closeness trend except for 19 species of pesticides. Fludioxonil and chlorpyrifos are recognized as the "bridge" of pesticides network with their high betweenness centrality. The results of network analysis show the "relation" data, which could not represent through out the conventional statistical analysis, among the pesticide residues. We hope that the network analysis method will be appropriate and precise tool for analyzing pesticide residues via elaboration and optimization.

• Analytical Science and Technology
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• v.21 no.6
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• pp.518-525
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• 2008

Mandipropamid is a new mandelamide-type fungicide to control foliar Oomycete pathogens in some vegetables. An analytical method was developed to determine mandipropamid residues in agricultural commodities using high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). Mandipropamid was extracted with methanol from grape, tomato, green pepper, Chinese cabbage and potato samples. The extract was diluted with saturated sodium chloride solution and distilled water, and dichloromethane partition was followed to recover the mandipropamid from the aqueous phase. Florisil column chromatography was employed to further remove interfering co-extractives prior to HPLC analysis. Reverse-phased HPLC was successfully applied to determine mandipropamid in sample extracts with the detection at its ${\lambda}_{max}$ (223 nm). Overall recoveries of mandipropamid from fortified samples averaged $99.8{\pm}1.7$ (n=6), $89.3{\pm}5.3$ (n=6), $98.7{\pm}2.2$ (n=6), $99.7{\pm}6.8$ (n=6) and $91.1{\pm}3.1$ (n=6) for grape, tomato, green pepper, Chinese cabbage and potato, respectively. Limit of quantification of the method was 0.02~0.04 mg/kg for all samples. A LC/mass spectrometry with selected-ion monitoring was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to determine the terminal residue of mandipropamid in agricultural commodities.

• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.15-21
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• 2011

Monitoring or follow-up surveying pesticide residues in agricultural commodities is the key to meet the international regulations and to enhance international competitiveness of Korean agricultural commodities. Six neonicotinoid insecticides, acctamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam were monitored in 95 paprika samples collected from Gyeongnam area. Thc pesticide residues were extracted by EN 15662 buffer based on the QuEChERS method, clean-upped with dispersive solid-phase extraction method to remove interfering pigments, and analyzed using UPLC-MS/MS. The neonicotinoid pesticides were detected in 90.5% of the paprika samples. Two or more pesticides were detected in 82.3% of samples. Although detection frequencies were high, all samples complied with the maximum residue limits (MRLs) set by both the Korea Food and Drug Administration (KFDA) and Japanese Ministry of Health, Labour and Welfare.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.165-175
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• 2010

A gas chromatographic (GC) method was developed to determine residues of captan, folpet, captafol, and chlorothalonil, known as broad-spectrum protective fungicides for the official purpose. All the fungicide residues were extracted with acetone containing 3% phosphoric acid from representative samples of five agricultural products which comprised rice, soybean, apple, pepper, and cabbage. The extract was diluted with saline, and dichloromethane partition was followed to recover the fungicides from the aqueous phase. Florisil column chromatography was additionally employed for final cleanup of the extracts. The analytes were then determined by gas chromatography using a DB-1 capillary column with electron capture detection. Reproducibility in quantitation was largely enhanced by minimization of adsorption or thermal degradation of analytes during GLC analysis. Mean recoveries generated from each crop sample fortified at two levels in triplicate ranged from 89.0~113.7%. Relative standard deviations (RSD) were all less than 10%, irrespective sample types and fortification levels. As no interference was found in any samples, limit of quantitation (LOQ) was estimated to be 0.008 mg/kg for the analytes except showing higher sensitivity of 0.002 mg/kg for chlorothalonil. GC/Mass spectrometric method using selected-ion monitoring technique was also provided to confirm the suspected residues. The proposed method was reproducible and sensitive enough to determine the residues of captan, folpet, captafol, and chlorothalonil in agricultural commodities for routine analysis.