• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.39-44
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• 1998

Three pesticides for paddy rice, iprobenfos, isoprothiolane, and diazinon were examined on some environmental factors, their hydrolysis, microbial degradation, and photolysis in aqueous systems. Iprobenfos was mainly degraded by microorganisms and its half-life was 5.7 days at $28^{\circ}C$ in aqueous systems. Hydrolysis of iprobenfos was accelerated by the higher temperature, but its photodegradation was accelerated by the lower pH. Isoprothiolane was rapidly decomposed by two factors, microorganisms and sunlight. The half-life of isoprothiolane by sunlight was 91 days at pH 9.0, while it was 13 days at pH 4.0 and 16 days at pH 7.2. However, it was shortened under low pH condition. In aqueous system, diazinon was degraded by all of three factors and its degradation rate was remarkably accelerated by acidic solution. Main degradation factors of iprobenfos, isoprothiolane, and diazinon in the aqueous system were investigated by microbial degradation, photolysis, and hydrolysis, respectively. The strains of microbial degradation for iprobenfos, isoprothiolane, and diazinon in the aqueous environment were identified as Pseudomonas putida, Alcaligenes xylosoxydans ss, Klebsiella planticola/ornithinllytica, respectively. The similarity rates of identity were $54.8{\sim}86.2%$ with biolog-system.

• Journal of agricultural medicine and community health
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• v.21 no.2
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• pp.159-171
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• 1996

It is investigated to determine the removal efficiency of organic - phosphorus insecticide residues in lettuce by washing processes, the 5 washing solution (stagnant tap water, flowing tap water, alkaline solution, acidic solution) were used with the washing time(10, 30, 50sec) and frequencies(1, 2, 3 washing, 2 rinsing). The removal efficiency of residual pesticides by 5 washing methods was increased on the more washing time and frequency, and also was the highest on the 3 times washing for each 50 sec. The removal rate with stagnant tap water was 33.7% of Diazinon, 45.7% of Dimethoate and 24.6% of Fenitrothion, but 29.4% of Diazinon, 37.7% of Dimethoate and 24.5% of Fenitrothion with flowing tap water. Therefore, the former was significantly higher effective than the latter one. The removal rate of residual pesticides with alkaline solution showed 32.1% of Diazinon, 49.5% of Dimethoate and 29.9% of Fenitrothion, and 30.4% of Diazinon, 36.4% of Dimethoate and 21.0% of Fenitrothion with acidic solution. The washing efficiency of neutral detergent showed the most effective result than others with 47.1% of Diazinon, 58.0% of Dimethoate and 39.5% of Fenitrothion. Consequently, it's appeared that the neural detergent washing was the most effective method on the 3 times washing for each 50 sec.

• Journal of Acupuncture Research
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• v.29 no.2
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• pp.9-14
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• 2012

Objectives : This study was designed to evaluate the pesticide residue of herb medicine through high density ozone water cleaning system. Materials and Methods : We purchased ginseng(Panax ginseng) on market and sprayed pesticides (Diazinon) on ginseng. We analyzed pesticide residue according to washing methods(untreated, ozone water cleaning, ultrasonic cleaning, Water cleaning). As a result of each washing methods, in ozone water cleaning method pesticide residue was much less remained than in Ultrasonic Cleaning method and water cleaning method. Conclusions : High density ozone water cleaning is the best method for removing pesticides of herbal medicine.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.238-243
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• 2004

To investigate the changes in content of residual pesticides for safety production of young radishes in the production steps in greenhouse and to evaluate the safety of young radishes in the final consuming step, biological half-life of pesticides (diazinon, endosulfan) in packaging products was studied. Samples were collected regularly from 2 hours to 10 days after the distribution of pesticides in young radishes. The contents of residual pesticides in young radishes during cultivating in greenhouse as the levels of distribution concentrations reduced with time. During 10 days of pesticides distribution, decomposition rate of pesticides were diazinon > endosulfan. A half-life of endosulfan was 0.6 day longer than diazinon because endosulfan derived persistent endosulfan sulfate. To produce the safe young radish, after the distribution of the pesticides the desirable harvest time based on maximum residue limit (MRL) was 6th day diazinon for and 10th day for endosulfan.

• Journal of Food Hygiene and Safety
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• v.11 no.2
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• pp.89-97
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• 1996

This study was carried out to determine the pesticide residues in rice bran, crude rice bran oil and the oil of various stages of refining process. Each samples were analyzed for 41 pesticide residues by multiclass multiresidue methods with GC-ECD, NPD and identified by GC-MSD. Rice bran were detected cypermethrin, diazinon, dichlofluanid, and its level were ranged from 0.01~0.122 ppm. Crude rice bran oil were detected cypermethrin, diazinon, dichlofluanid, dimethoate, etrimfos, flucythrinate, and its level were ranged from 0.015~0.654 ppm Crude rice bran oil has the higher level of pesticide residues and more varieties of pesticides than rice bran. But pesticide residues in the crude rice bran oil was found to be almost removed then pigment was decolorized by absorption using active carbon and clealy removed by thermolysis for deodorization.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.338-351
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• 2019

BACKGROUND: To investigate distribution and seasonal variation of concentration and flux of pesticides in Han river basin, water samples were examined at 24 sites in 2012 and 2014. METHODS AND RESULTS: Water samples were collected four times per year and subjected to liquid-liquid partition extraction followed by GC-ECD/NPD analysis. Of fifteen pesticides detected, iprobenfos, diazinon, isoprothiolane, endosulfan sulfate and oxadiazon were detected in a higher frequency, while fenoxanil, carbofuran, fenitrothion, butachlor and metolachlor were only detected in a sample. Pesticides with high occurrences, iprobenfos, diazinon, isoprothiolane, endosulfan sulfate and oxadiazon were detected in residue level of 0.01-0.46, 0.01-0.24, 0.03-0.85, 0.02-0.06 and 0.05-0.24 ㎍/L, respectively. Carbofuran and acetanilide herbicides were found at lower frequencies, but their concentrations were one order of magnitude higher than those of the others. CONCLUSION: Discharge of pesticides in downstream area were mainly contributed from rice farming and suburban horticulture, while pesticide occurrences in upstream area, such as Donggang river basin were caused by highland agriculture for cabbage and potato production. Despite the influx of pesticides from tributaries through intensive agriculture areas, pesticide concentration in the main stream water was low due to the dilution effect from the upstream. Therefore, the water quality was considered to be good at the most downstream, the effluent of Paldang dam.

• Journal of Food Hygiene and Safety
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• v.1 no.2
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• pp.181-186
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• 1986

Organophosphorus insecticide residues were investigated in six kinds of fruits and five kinds of vegetables.The materials used in this experiment were grape, musk melon, apple, peach, plum, apricot, lettuce, green pepper, cucumber, pumpkin and tomato which were collected from June to september 1986 in Seoul. Residual pesticides investigated were Diazinon, Parathion, MEP (Fenitrothion), Malathion, EPN, MPP (Fenthion), PAP (Phenthoate) and Dimethoate and all samples were analysed by gas chromatographic technique with NPD (Nitrogen Phosphorus Detector). No sample was found to approach proposed national maximum residue limits in Korea.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.57-62
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• 2006

Six organophosphorus, one organochlorine, and three synthetic pyrethroid pesticides were analyzed for their residues during washing and hot-air drying of red peppers conducted in the production of powder. The residue ratio in organophosphorus pesticides was 33% in chlorpyrifos, 31 % in diazinon, 50% in methidathion, 80% in EPN, 28% in fenitrothion, and 60% in profenofos. The ratio in pyrethroids was 109% in cypermethrin, 102% in deltamethrin, and 106% in fenvalerate. That in organochlorine was 56% in ${\alpha}$-endosulfan and 90% in ${\beta}$-endosulfan. The results were greatly different between organophosphorus and pyrethroid pesticides. UV irradiation along with hot-air drying brought about a remarkable reduction of the residues, up to 70% as compared with hot-air drying only. The removal effect was most remarkable in pyrethroids, which are hardly removed by hot-air drying. The color of the pepper was not changed during UV irradiation. The use of oxidizing agents such as hydrogen peroxide or chlorine dioxide during washing did not show a remarkable removal of residues. The residue ratio was not affected whether the pesticide is contaminated artificially or naturally.

• 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.

• Korean Journal of Agricultural Science
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• v.32 no.2
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• pp.215-221
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• 2005

The residual study of pesticide has been used in various areas, such as food safety, environmental protection, establishment of tolerance, and explaining the pathway and reaction mode of pesticides, and its importance was expected to increase further more. The aspect of food safety, the pesticide residue survey have been practiced at many organizations, but there were no verification of analytical results at present. In this experiment, we focused on instrumental stability, including response of each instrument and the recovery ratio of each organization's method. As samples for this experiment, we prepared cucumber and sesame, and chose 4 pesticides (bifenthrin, chlorpyrifos, diazinon, and ethoprophos), which were mostly detected from pesticide residue survey and widely used for each crop. The standard deviation of peak areas in the chromatogram of each pesticide were under 1.212 %, so it showed that most instruments were stable. The relationship of recovery ratio of each organization were over 0.996 for every pesticide and each organization. Finally, the analytical results for pesticide residue from each participated organization were not statically significant and we could put confidence in the result from each organization.