• Journal of Environmental Science International
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• v.18 no.12
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• pp.1369-1381
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• 2009

The simultaneous determination of residual pesticides was developed using a gas chromatography. In this study, a simple and reliable methodology was improved to detect 175 kinds of residual pesticides by a liquid-liquid extraction procedure, followed by chromatographic analysis by gas chromatography. The 175 kinds of residual pesticides was classified into 4 groups according to the chemical structure, column type, resolution and sensitivity. The soybean sample selected for recovery experiment was not detected any pesticides. The recovery rates were ranged from 70.6% to 119.7% in most pesticides. The relative standard deviation (RSD 0.3~5.6%) was lower than 5.6% in all cases. The limits of detection (LOD) was lower than the maximum residue levels established by Korean legislations. The method has been successfully applied to the analysis of approximately 130 real samples.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.223-229
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• 2015

BACKGROUND: It is important to understand residual patterns of pesticides applied on crops for ensuring their safety in agricultural products. However, there are few studies on the residual patterns of pesticides in minor crops, which are small in cultivation area. In this study, residual amounts of bifenthrin and chlorfenapyr sprayed on perilla leaf as a minor crop were investigated to know their residual patterns. METHODS AND RESULTS: Bifenthrin and chlorfenapyr were sprayed 2 or 3 times on perilla leaves at a week interval prior to harvest, and the perilla leaves were collected at 0, 1, 3, 5 and 7 days after the final application of pesticides. Recoveries for residual analysis of pesticides spiked on perilla leaves with concentrations of 0.1 and 0.5 mg/kg were 81.9-104.8%. The residual amounts of pesticides interpreted using first order kinetics model show that dissipation constants of bifenthrin and chlorfenapyr in perilla leaves were 0.0724-0.0535 and $0.0948-0.0821day^{-1}$, respectively. In addition, the dissipation half-lives in perilla leaves were 9.6-12.9 days for bifenthrin and 7.3-8.4 days for chlorfenapyr. When pre-harvest residue limits (PHRL) of bifenthrin and chlorfenapyr at 10 days before harvest calculated on the basis of the dissipation constants and maximum residue limits of the pesticides were calculated as 17.1 for bifenthrin and 15.9 mg/kg for chlorfenapyr. CONCLUSION: Therefore, the PHRL calculated using the time-dependant residual patterns of pesticides in perilla leaves and their regression analysis may be used as experimental evidences in order to ensure the safety of pesticides in perilla leaves before harvest.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.205-210
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• 1998

This study was carried out for the dietary safety based on the level of pesticide residues in 19 kinds of agricultural products consumed in Kangwon-do, Korea. From April 1995 to December 1997, eight organochlorine pesticides in 673 samples were analyzed by using GLC-ECD. According to the results, one kind of pesticides were detected in 159(23.6%) samples and two kinds were in 24(15.1%). While Chlorobenzilate, Dicofol and Tetradifon were not found. Detection ranges of pesticides were $0.001{\sim}0.117ppm$ for DDT, $0.001{\sim}0.095ppm$ for ${\gamma}-BHC$, $0.001{\sim}0.067ppm$ for ${\alpha},{\beta}-Endosulfan$, $0.003{\sim}0.250ppm$ for Chlorothalonil and 0.033ppm for Captafol. Average residues were 0.006ppm for DDT, 0.009ppm for ${\gamma}-BHC$, 0.008ppm for ${\alpha},{\beta}-Endosulfan$, 0.024ppm for Chlorothalonil and 0.033ppm for Captafol, respectively. Consequently, all of the organochlorine pesticide residues in the analyzed samples were within the maximum residue limits.

• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.127-132
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• 2009

The purpose of this study is to examine changes in the pesticides residues in pepper powder by storage conditions. Analysis of pesticide residues was performed using multiresidue analytical methods and the number of pesticides detected from 60 pepper powders was 7 pesticides such as cypermethrin, fenvalerate, kresoxim-methyl, chlorpyrifos, chlorfenapyr azoxystrobin, tebuconazole. The concentrations of cypermethrin and tebuconazole were exceeded their maximum residue limits (MRLs). The degradation patterns of pesticides at $-5^{\circ}C$ were compared to those at $20^{\circ}C$ and $4^{\circ}C$. Without reference to storage temperature, degradation rates of azoxystrobin and fenvalerate were above 80%. Degradation rate of chlorpyrifos was 47% at storage $4^{\circ}C$, $20^{\circ}C$ and 34% at storage $-5^{\circ}C$. During each storage peroid, the degradation patterns were more lower at $-5^{\circ}C$ than at $20^{\circ}C$ and $4^{\circ}C$.

• Food Science and Preservation
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• v.9 no.1
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• pp.46-50
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• 2002

This study was carried out for dietary safety based on the level of pesticide residues in 17 kinds of the agricultural products (apple, cabbage, cabbage kor, carrot, cucumber, pepper, onion, potato, radish, spring onion, pumpkin, lettuce, garlic, drapwort, spinach, leek crown daisy) consumed in Kyunggi-do and Inchon-city that provided for the army. From January 1998 to December 2001, ten organochlorine pesticides in 1075 samples were analyzed by using GC-ECD. According to the results, one kind of pesticides was detected in 135(12.5%) samples, and two kinds were in 7 (5.18%). While dicofol and tetradifon was not fecund. Detection rate of pesticides were 9.02% for $\alpha$, $\beta$-endosulfan, 2.8% far chlorothalonil, 0.46% for γ-BHC, 0.40% for chlorobenzilate, 0.33% for folpet, 0.28% far DDT, 0.15% for captafol, and 0.11% for captan. Dectection ranges of pesticides were from 0.001 to 0.092 ppm for $\alpha$, $\beta$-endosulfan, from 0.003 to 0.023 ppm for chlorothalonil, from 0.003 to 0.006 ppm far γ -BHC, from 0.001 to 0.003 ppm for DDT, from 0.009 to 0.095 ppm for folpet, 0.05 ppm for captan, 0.01 ppm for captafol, and 0.008 ppm far chlorobenzilatel respectively. Consequentlyl all detected pesticide levels in samples were below maximum residue limits(MRLs) in Korea and Codex.

• Analytical Science and Technology
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• v.22 no.3
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• pp.201-209
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• 2009

Four heavy metals (Pb, Cd, As, and Hg) in 38 species (total 325 samples) of oriental animality medicines were monitored by inductively coupled plasma-mass spectrometry (ICP-MS) and automatic mercury analyzer (AMA). The detected concentration range of Pb, Cd, As was presented as $0.02{\mu}gkg^{-1}$ $(D.L){\sim}11.29mgkg^{-1}$, $0.01{\mu}gkg^{-1}$ $(D.L){\sim}2.50 mgkg^{-1}$, $0.12{\mu}gkg^{-1}$ $(D.L){\sim}5.27mgkg^{-1}$, respectively. In case of Hg, it the concentration range was $0.01{\sim}77.11mgkg^{-1}$ except one sample which exceeded detection limit. In all samples of Amydae Carapax and Gallnut, it was not detected over the maximum residue limits of metals. Pb is in charge of the greatest portion of contamination in 22 species of animality medicines, and in case of Hg, 54.46% of total samples were over the maximum residue limits. Therefore, environmental levels of Pb and Hg are needed to continue the researches and the studies for tracking pollution source are required.

• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.446-452
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• 2011

BACKGROUND: To investigate the dissipation patterns of 3 pesticides, azoxystrobin, difenoconazole and iprodione, on green garlic after field treatment pesticides were treated as foliar treatment by single application at recommended and double the recommended rates. METHODS AND RESULTS: Residue samples were harvested at 0, 1, 2, 5, 7 and 10 days post-treatment for azoxystrobin and 0, 1, 2, 5, 7, 10, 15 and 21 days post-treatment for difenoconazole and iprodione. After preparation the fortified samples were extracted and analyzed by gas chromotography-electron capture detector (GC-ECD) to determine the residue levels. Recoveries ranged from 87 to 109% for azoxystrobin, difenoconazole and iprodione at two different levels. The limit of Quantification (LOQ) values were 0.002 mg/kg for azoxystrobin and difenoconazole and 0.01 mg/kg for iprodione. CONCLUSION(S): Half-lives of azoxystrobin, difenoconazole and iprodione in green garlic after treatment were 1.2, 3.8 and 3.2 days at recommended and 1.4, 3.3 and 3.2 at double the recommended rate, respectively. Residue level of azoxystrobin, difenoconazole and iprodione in green garlic were below the maximum residue limits (MRLs) at 0 day, 0 day and 5 days, respectively. Therefore, these pesticide were considered that residues was satisfied to the requirement of domestic trade related to the consumer safety.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.453-462
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• 2011

This study was carried out to survey the residual characteristics of pesticides and assess their safety. Nineteen agricultural commodities, collected from wholesale and traditional markets in Cheongju. Nineteen agricultural commodities including perilla leaves were collected from the markets on October 29th, 2010. Total 240 pesticides which can be analyzed by multiresidue analysis method by GLC and HPLC were monitored and the pesticides detected were confirmed by GC-MSD and LC-MS. Five pesticides, alachlor, bifenthrin, endosulfan, procymidone and triflumizole, were detected from five samples, such as welsh onion, leek and celery in case of wholesale market and perilla leaves and welsh onion in case of traditional market. Detection rate of 13.2% was obtained as a result of pesticide analysis but 2.6% of the pesticides detected exceeded their maximum residue limits. The estimated daily intakes (EDIs) and maximum permissible intakes (MPIs) of the pesticides detected were less than 26% and 0.05% of their acceptable daily intakes (ADIs) respectively, representing that residue levels of the pesticides detected would be safe.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.388-394
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• 2014

BACKGROUND: Aclonifen is used as a systemic and selective herbicide to control a wide spectrum broad-leaf weeds by inhibition carotenoid biosynthesis, and then its MRLs(Maximum Residue Limits) will be determined in onion and garlic. In this study, a new official method was developed for aclonifen determination in agricultural products to routinely inspect the violation of MRL as well as to evaluate the terminal residue level. METHODS AND RESULTS: Aclonifen was extracted from crop samples with acetone and the extract was partitioned with dichloromethane and then purified by silica solid phase extraction(SPE) cartridge. The purified samples were detected GC using an ECD detector. Limits of detection(LOD) was 0.001 mg/kg and quantification(LOQ) was 0.005 mg/kg, respectively. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, $10{\times}LOQ$, $50{\times}LOQ$, n=5). The recoveries were ranged from 74.3 to 95.0% with relative standard deviations(RSDs) of less than 8%. All values were consistent with the criteria ranges requested in the Codex guidelines(CAC/GL 40). CONCLUSION: The proposed analytical method was accurate, effective and sensitive for aclonifen determination and it will be used to as an official method in Korea.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.273-281
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• 2012

This study was conducted for the establishment of the analytical method of pesticide residues in rice straw for 9 pesticides; etofenprox, tricyclazole, diazinon, edifenphos, propiconazole, carbaryl, carbofuran, 3-hydroxy carbofuran and 3-keto carbofuran and for the monitoring of these pesticides in rice straw for livestock feed in Korea. These pesticides were classified into 4 groups according to analytical instrument condition. Group 1 (HPLC-UVD1) included tricyclazole and etofenprox while group 2 (HPLC-UVD2) included propiconazole and edifenphos. Group 3 (HPLC-FLD) included carbaryl, carbofuran, 3-hydroxy carbofuran and 3-keto carbofuran. Group 4 (GC-NPD) included Diazinon. The dried rice straw samples were extracted with acetone and purified by liquid-liquid partition and solid phase extraction (SPE): Combination of Florisil SPE and amino-propyl SPE was used for group 1 and group 2, amino-propyl SPE for group 3, and Florisil SPE was for group 4. Recovery was in the ranged 70~110% and the limits of quantitation (LOQ) were lower than the half of maximum residue limits. Therefore this method was proved to be efficient for monitoring of these pesticides residue in rice straw. A total of 18 rice straw samples from 6 provinces in Korea in 2010 were analyzed using established method and, only 3-keto carbofuran was detected in one sample at concentration of 0.04 mg/kg.