• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.93-103
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• 2016

A simultaneous analytical method was developed for the determination of isoxaflutole and metabolite (diketonitrile) in agricultural commodities. Samples were extracted with 0.1% acetic acid in water/acetonitrile (2/8, v/v) and partitioned with dichloromethane to remove the interference obtained from sample extracts, adjusting pH to 2 by 1 N hydrochloric acid. The analytes were quantified and confirmed via liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive-ion mode using multiple reaction monitoring (MRM). Matrix matched calibration curves were linear over the calibration ranges ($0.02-2.0{\mu}g/mL$) for all the analytes into blank extract with $r^2$ > 0.997. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. The recoveries were ranged between 72.9 to 107.3%, with relative standard deviations (RSDs) less than 10% for all analytes. All values were consistent with the criteria ranges requested in the Codex guideline (CAC/GL40, 2003). Furthermore, inter-laboratory study was conducted to validate the method. The proposed analytical method was accurate, effective, and sensitive for isoxaflutole and diketonitrile determination in agricultural commodities.

• Food Science and Preservation
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• v.6 no.3
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• pp.303-307
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• 1999

Compressive strength reduction characteristics of 4 different linerboards(SC, KA, SK and IK) as influenced by temperature and humidity were investigated by ring crush test. No significant effect of temperature on the reduction of compressive strength was found for samples prepared at 5$^{\circ}C$ and 30$^{\circ}C$. At the relative humidity of 66 percents, IK linerboard showed the lowest reduction of the compressive strength. At the relative humidity of 93 percents, KA linerboard lost 40 percents of its initial compressive strength while SK linerboard lost its strength up to 56 percents. The result indicated that KA linerboard was the most cost effective and material with the highest compressive strength among tested linerboards.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.288-288
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• 2009

WTO가 진행되고 한미 FTA 협상타결로 농업농촌이 어려움을 격고 있으며 EU, 중국, 인도 등과의 FTA 협상도 검토되고 있다. 또한 소득수준 향상으로 소비자들이 웰빙 건강식품에 대한 관심이 고조되면서 이제는 농산물의 안전성과 기능성, 맛 등이 우수한 고품질 안전농산물 생산이 농업의 핵심과제로 대두되고 있다. 이와 같이 급변하는 농업여건에 대응해 나가기 위해서는 농업정책의 최우선과제인 친환경농업에 적극 동참하여 안전하고 우수한 농산물을 생산해야 할 것이다. 잎들깨의 재배에 있어 주생산 요소의 한 가지는 영양생장을 잘 조절해야 하고 기비보다는 추비에 보다 많은 기술이 요구되고 있다. 이에 본 연구의 목적은 잎들깨 추비시용에 있어 화학비료를 대체 유기질 비료를 이용하여 추비수준별 생육 및 수량성을 구명 하는데 있다. 재배방법은 재식거리는 10 cm${\times}$7cm(137,500주/10a) 로 하였으며 기비는 유기질비료(N-P-K=3.2:4.2:1.1)를 N량 기준으로 5.2kg/10a 을 시용하였다. 추비시용 처리는 10a당 N 0kg, N1.2kg, N1.5kg, N 1.8kg 등 4처리를 두었으며, 추비는 유기질 비료 (N-P-K=4.0-2.0-1.5)를 N 기준으로 생육에 따라 매회 수확 후에 시용 하였으며, 시용 방법에 있어 관수는 1 회 급여시 유기질 비료를 10a당 물 5톤에 희석하여 총 5회를 주었으며 관수방법은 점적호스를 이용하여 저면 관수 하였다. 재배기간 중 10a당 T-N 시용량은 N 0kg 재배는 5.2kg, N 1.2kg 재배는 11.2kg, N 1.5kg재배는 12.7kg, N 1.8kg재배는 14.2kg을 시용하였다. 재배 후 처리별 N 흡수량은 N 1.8kg구 33.1kg, N 1.5kg구 30.0kg, N 1.2kg구 25.7kg, N 0kg구 18.1kg순으로 나타났다. 생육은 초장, 경경, 엽장, 엽폭, 엽중은 추비 시용량이 높을수록 향상되었고, 마디수 발생은 추비 수준 간 변동이 없었다. 병해충 발생정도는 병은 시들음병, 역병, 노균병 순으로 발생하였고, 충은 잎말이나방, 잿빛곰팡이, 진딧물 순으로 발생되었다. 수량성은 N 1.5kg 재배구가 N 1.2kg 대비 115%, N 0kg 대비 169%를 수확하여 타 처리에 비해 비교적 높게 나타났다.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.155-162
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• 2018

This study attempts to analyze the consumers' preference on Korean Red Ginseng Tonic, which is an essential product to revitalize Korean ginseng industry, using choice experiment method. The attributes used in the choice experiment were the ginseng age, good agricultural products(GAP), sugar, and price. A total of 1,796 experiments were collected and the value of each preferred attributes was estimated using a multinomial logistic model. The result shows that the products made from six-year-old and GAP(Good Agriculture Practice) approved Korean ginseng with less sugar were preferred. These estimated monetary values of marginal willingness to pay were about 94,000 KRW, 89,000 KRW, 5,000 KRW, respectively. Thus, the efforts to introduce and advertize GAP approved ginseng while developing new products with preferred attributes by general publics are necessary in the short run. In addition, we may need to consider developing the way to promote products using 4- and 5-year-old ginsengs, which are relatively underestimated in their health effectiveness but highly productive for farmers in the long run.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.22-29
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• 2019

Validamycin A is an aminoglycoside fungicide produced by Streptomyces hygroscopicus that inhibits trehalase. The purpose of this study was to develop a method for detecting validamycin A in agricultural samples to establish MRL values for use in Korea. The validamycin A residues in samples were extracted using methanol/water (50/50, v/v) and purified with a hydrophilic-lipophilic balance (HLB) cartridges. The analyte was quantified and confirmed by liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive ion mode using multiple reaction monitoring (MRM). Matrix-matched calibration curves were linear over the calibration ranges (0.005~0.5 ng) into a blank extract with $R^2$ > 0.99. The limits of detection and quantification were 0.005 and 0.01 mg/kg, respectively. For validation validamycin A, recovery studies were carried out three different concentration levels (LOQ, $LOQ{\times}10$, $LOQ{\times}50$, n = 5) with five replicates at each level. The average recovery range was from 72.5~118.3%, with relative standard deviation (RSD) less than 10.3%. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL 40-1993, 2003) and the NIFDS (National Institute of Food and Drug Safety) guideline (2016). Therefore, the proposed analytical method is accurate, effective and sensitive for validamycin A determination in agricultural commodities.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.296-305
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• 2018

Spiroxamine, one of fungicides, is used to control powdery mildew in various crops and black yellow sigatoka in bananas. The major strength of spiroxamine is to control powdery mildew in various crops and bananas yellow sigatoka in bananas. The compound has shown a high level of activity, good persistence and crop tolerance. Besides powdery mildew, good control of rust, net blotch and Rhynchosporium diseases been indicated in cereals, together with a complementary activity against Septoria diseases. In 2017, the maximum residue limit (MRL) of spiroxamine established in Korea. According to Ministry of ood and rug afety) regulations, spiroxamine residues defined only parent compound. Thus, a analytical method is needed to estimate the residue level of the parent compound. The objective of this study was to develop and validate analytical method for spiroxamine in representative agricultural commodities. Samples were extracted with acetonitrile and partitioned with dichloromethane to remove the interfering substances. The analyte were quantified and confirmed liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive-ion mode using multiple reaction monitoring (MRM). Matrix matched calibration curves were linear over the calibration ranges ($0.0005{\sim}0.1{\mu}g/mL$) for the analyte in blank extract with coefficient of determination ($r^2$) > 0.99. For validation purposes, recovery studies will be carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. The recoveries 70.6~104.6% with relative standard deviations (RSDs) less than 10%. All values were consistent with the criteria ranges in the Codex guidelines (CAC/GL40, 2003) and MFDS guidelines. proposed analytical method be used as an official analytical method in the Republic of Korea.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.242-250
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• 2019

An analytical method was developed for the determination of fenquinotrione, a triketone herbicide, in agricultural products. Fenquinotrione was metabolized to KIH-3653-M-2 in plants. Analyte extraction was conducted using 2% formic acid in acetonitrile and cleaned up using a hydrophillic-lipophillic balance (HLB) cartridge. The limits of detection (LOD) and quantification (LOQ) were 0.004 and 0.01 mg/kg, respectively. Matrix-matched calibration curves were linear over the calibration ranges ($0.001{\sim}0.1{\mu}g/mL$) into a blank extract with $r^2>0.99$. The recovery results for fenquinotrione and KIH-3653-M-2 ranged between 81.1 to 116.2% and 78.0 to 110.0% at different concentration levels (LOQ, $10{\times}LOQ$, $50{\times}LOQ$) with relative standard deviation (RSD) less than 4.6%. All values were corresponded with the criteria ranges requested in 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 fenquinotrione in the Republic of Korea.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.210-217
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• 2015

Ipfencarbazone is a herbicide of the tetrazolinone class, and is believed to be an inhibitor of very long chain fatty acids (VLCFAs), which control cell division in weeds. The objective of this study was to develop and validate an official analytical method for ipfencarbazone determination in agricultural products. The ipfencarbazone residues in agricultural products were extracted with acetone, partitioned with n-hexane, and then purified through silica SPE cartridge. Finally, the analyte was quantified by gas chromatograph-electron capture detector (GC-ECD) and confirmed with gas chromatograph/mass spectrometer(GC/MS). The linear range of ipfencarbazone was 0.01 to 1.0 mg/L with the coefficient of determination ($r^2$) of 0.9999. The limit of detection (LOD) and quantification (LOQ) was 0.003 and 0.01 mg/kg, respectively. In addition, average recoveries of ipfencarbazone ranged from 80.6% to 112.3% at the different concentration levels LOQ, 10LOQ and 50LOQ, while the relative standard deviation was 2.2-8.6%. All values were consistent with the criteria ranges requested in the CODEX guidelines. Furthermore, and inter-laboratory study was conducted to validate the method. This proposed method for determination of ipfencarbazone residues in agricultural products can be used as an official analytical method.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.290-297
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• 2017

The purpose of this study was developed for the determination of tridemorph in agricultural commodities samples. Tridemorph residues in samples were extracted with acetonitrile, partitioned with saline water, and then purified using and aminopropyl ($NH_2$) SPE catridge. The purified samples were quantified and confirmed via liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive ion mode using multiple reaction monitoring (MRM). Matrix-matched calibration curves were linear over the calibration ranges (0.005~2.5 ng) into a blank extract with $r^2$ > 0.999. The limits of detection and quantification were 0.001 and 0.005 mg/kg, respectively. The average recovery ranged between 75.9% and 103.7% at different concentration levels (LOQ, 10 LOQ, 50 LOQ, n = 5) with relative standard deviations (RSDs) less than 9.0%. An interlaboratory study was conducted to validate the method by Korea Advanced Food Research Institute. The average recovery ranged between 87.0% and 109.2% at different concentration levels (LOQ, $10{\times}LOQ$, $50{\times}LOQ$, n = 5) with relative standard deviations (RSDs) less than 8.0%. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL40, 2003) and Food Safety Evaluation Department guidelines (2016). The results prove that the developed analytical methods is accurate, effective and sensitive for tridemorph determination.

• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.245-256
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• 2008

The current legislation in South Korea clearly states that the tolerance threshold on the adventitious presence of GMO in environment-friendly agricultural products is 3.0% and no GM seed should be detected in their planting seed batches. To date, in Korea, there is no approved GM crop for commercial cultivation in field. However, several GM crops including rice, Chinese cabbage, potato and wild turf grass are currently under risk assessment for their environmental release. Also Korean government (Rural Development Administration, RDA) announced that 11 institutes including universities have been currently certified to carry out a risk assessment of GM crops. Meanwhile, the cultivated area and certified quantities of environment-friendly crops (organic, pesticide-free and low-pesticide) are sharply increasing every year according to the report of National Agricultural Products Quality Management Service (NAQS). In detail, in 2007, the certified quantities of environment-friendly agricultural products were elevated up to 100-fold for organic, 171-fold for pesticide-free and 2,324-fold for low-pesticide crops when compared with those in 1999. The total certified quantity of environment-friendly cereal crops in 2007 was equivalent to 6.4% of total production of cereal crops. Moreover, 24% of total production of root and tuber crops such as potato and sweet potato were certified for environment-friendly agricultural products. In these circumstances, I strongly suggest that current legislations on GM crop's safety management should be revised to include strategies for the coexistence of GM with non-GM crops, especially environment-friendly crops before GM crop is approved to be cultivated for commercialization. Since all types of crops are grown in an open environment, the adventitious presence of GM crops among non-GM crops is inevitable if appropriate measures for coexistence are not established for species by species such as isolation distance, workable management measures to minimize admixture.