Jeong-In Hwang

Monitoring of Pesticide Residues and Risk Assessment for Fruit Vegetables and Root Vegetables of Environment-friendly Certified and General Agricultural Products

BACKGROUND: This study was conducted to monitor the residue of pesticides and to assess their risk in domestic agricultural products, such as fruit vegetables, tomatoes, oriental melons and root vegetables, garlic, potatoes and onions. METHODS AND RESULTS: 250 samples containing both general and environment-friendly certified agricultural products were collected from traditional markets and supermarkets in 6 cities. 132 pesticides except for herbicides were analysed using the multi-residue methods by GC/ECD, GC/NPD and HPLC/UVD. 17 kinds of pesticides were detected from 42 samples, which were 32 general, 1 organic, 4 pesticide-free and 5 low pesticide agricultural products. Among those, myclobutanil detected in 1 potato and procymidone detected in 10 oriental melons were unregistered pesticides for using in Korea. Fenbuconazole detected in 1 potato and phorate detected in 1 tomato were exceeded over the MRLs established by Korea Food and Drug Administration. CONCLUSION: Based on these results, a risk assesment was conducted using a percentage of acceptable daily intake(%ADI). %ADI ranged from 0.0064% to 4.6035%, and showed these values have no effect on human health.

Monitoring of Pesticide Residues and Risk Assessment for Cereals and Leafy Vegetables of Certificated and General Agricultural Products

BACKGROUND: This study was conducted to monitor the current status of pesticide residues and to assess their risk in domestic agricultural products. The samples were rice, barley, lettuce and perilla leaf. These four types of agricultural products were those with GAP(Good Agricultural Practice) certification, organic agricultural products, pesticide-free agricultural products or general agricultural products. METHODS AND RESULTS: They were purchased from traditional markets and supermarkets of 12 regions in Korea from July to August 2010. The total number of samples was 259 for agricultural products and these were analyzed by GC/ECD, GC/NPD and GC/MSD. We used multiresidue methods to analyze for 110 different pesticides except for herbicides. CONCLUSION: In this study, residual pesticides were detected in 18 samples. Among these general agricultural products, organic agricultural products and products with GAP-certification were detected in 12, 4 and 2 samples, respectively. Detection rates of general agricultural products, organic agricultural products and products with GAP- certification were 4.6%, 1.5% and 0.8% respectively. Pesticides were not detected in pesticide-free agricultural products. Their detection levels were less than their maximum residue levels. Their estimated daily intakes ranged from 0.0003% to 0.04302% of their acceptable daily intakes, of which the values have no effect on human health.

Plant Uptake and Distribution of Endosulfan and Its Sulfate Metabolite Persisted in Soil

The distributions of endosulfan (ED) residues (α-, β-isomers, and sulfate-metabolite) in cucumbers grown in soils treated with ED at concentrations of 20 and 40 mg kg-1 were assessed using indoor and outdoor experiments. In all treatments, degradation rates of the α-isomer in soils were higher than that of the β-isomer. In the indoor tests, uptake amounts of total ED by cucumbers, after 15 d of growth, were 7.8 and 14.5 mg kg-1 in 20 and 40 mg kg-1-treated pots, respectively. For growth time from 15 to 30 d, uptake amounts in 20 and 40 mg kg-1-treated pots were 3.8 and 7.9 mg kg-1, respectively. Outdoor tests resulted in smaller ED residues in cucumbers than those in indoor tests. In both indoor and outdoor tests, ED residues absorbed were highest in roots, and the α-isomer was the more frequently absorbed isomer. These results will be useful for determining management criteria for soil persistent pesticides.

Comparison of theoretical and experimental values for plant uptake of pesticide from soil

Pesticides that persist in soils may be taken up by the roots of plants. One way to assess plant uptake is to theoretically predict the extent of plant uptake using a mathematical model. In this study, a model was developed to predict plant uptake of pesticide residues in soils using various parameters, such as pesticide mobility within soil, plant transpiration stream, root–soil transfer rate, plant growth, and pesticide dissipation in either soils or plants. The accuracy of the model was evaluated by comparing the modeled concentrations with measured uptake concentrations of chlorpyrifos (CP) in lettuce, grown on treated soils with concentrations of approximately 10 and 20 mg kg-1 CP. Measured concentrations of CP in lettuce at 21, 30, and 40 d after planting were between the 5th and 95th percentiles of model variation. A high correlation coefficient of > 0.97 between modeled and measured concentrations was found. Coefficients of variation of mean factors to residual errors were between 25.3 and 48.2%. Overall, modeling results matched the experimental results well. Therefore, this plant uptake model could be used as an assessment tool to predict the extent of plant uptake of pesticide residues in soils.

Establishment of Safe Management Guideline Based on Uptake Pattern of Pesticide Residue from Soil by Radish

Received: 28 October 2016 / Revised: 7 November 2016 / Accepted: 10 November 2016 Copyright c 2016 The Korean Society of Environmental Agriculture This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ORCID

Application of Multiresidue Analysis Method of Unregistered Pesticides in Korea for Imported Food

BACKGROUND: Recently in Korea, the import of agricultural products is rising due to the increasing amount of trade. Unregistered pesticides, allidochlor, propachlor, propham, cycloate, diallate and pebulate are widely used as pesticides for rice cultivation in foreign countries, while they are not registered in Korea. Therefore, the residue amount of imported agri-foods should be verified using the proper official analytical method for each of them that has not registered in Korea. METHODS AND RESULTS: This work was conducted to apply the official method of Korea Food & Drug Administration (KFDA) for determining multi class pesticide multiresidues in agricultural commodities. Brown rice and orange which have different characteristics as a matrix were selected as representative samples for residue analysis. The recoveries of cycloate, diallate and pebulate by GC/MS in fortified brown rice and orange with levels of 0.04~0.4 mg/kg were ranged from 82.8% to 110.3%. The quantification limits of three pesticides in brown rice and orange were 0.04 mg/kg. CONCLUSION: As a result, this method can surely be used as an official method for routine analysis of unregistered pesticides in Korea for imported agri-food.

Suggestion for Establishment of Temporary MRLs and Safe use Guideline of the Organophosphorus Insecticides in Jinpi

Jinpi(Aurantii nobilis Pericarpium) is one of the most important material of oriental herbal medicine which is made from the peel of mandarin by washing with hot water and drying. Pesticides have necessarily used for mandarin cultivation according to their preharvest intervals (PHIs) but their maximum residue limits (MRLs) and PHIs for Jinpi are not established yet. This study is to know residue amount of organophosphorus insecticides in Jinpi and to establish the MRLs and PHIs for fenitrothion and phenthoate in Jinpi. Fenitrothion was sprayed once, twice and three times with 7 days interval before harvest. Its residue amount ranged from 0.14 to 1.17 mg/kg in mandarin, 0.59 to 4.02 mg/kg in its peel and 1.66 to 22.38 mg/kg in Jinpi. In case of phenthoate, it was sprayed with 10 days interval for 10 days before harvest. Its residue amounts in mandarin, its peel, and Jinpi ranged from 0.16 to 0.65, 0.69 to 2.41 and 1.69 to 11.3 mg/kg, repectively. Proposed MRLs of fenitrothion and phenthoate for Jinpi are suggested to 22.39 and 11.30 mg/kg, respectively. So we recommend PHIs of the pesticides that fenitrothion can be sprayed 3 times 7 days before harvest and in case of phenthoate, sprayed 3 times 10 days before harvest.

Monitoring of Pesticide Residues and Risk Assessment for Fruits in Market

BACKGROUND: This study was conducted to monitor residual pesticides in domestic agricultural products and to assess their risk to human health. METHODS AND RESULTS: 123 samples containing both general and environment-friendly certified agricultural products were purchased from traditional domestic markets and supermarkets in six provinces of Korea. Multiresidue analyses of one hundred twenty-two pesticides except for herbicides were performed with gas chromatography-electron capture detector, gas chromatography-nitrogen/phosphorus detector, and high-performance liquid chromatography. Sixteen pesticides were detected in 45 agricultural product samples, which were 38 general, 6 low pesticide and 1 of GAP agricultural product samples and the detection rate was 33.6%. Pesticides detected in agricultural product samples were cypermethrin, lufenuron, fenvalerate, bifenthrin, chlorfenapyr and iprodione. Residual concentration of 18 samples were exceeded the recommended maximum residue limit set by Ministry of Food and Drug Safety and two kinds of unregistered pesticides in korea were also detected in two samples. CONCLUSION(S): In order to do risk assessment by agricultural products consumption, estimated daily intake of residual pesticides were determined and compared to acceptable daily intake, referring to %ADI values. The range of %ADI values was from 0.038% to 2.748%. Taken together, it demonstrates the pesticides found in agricultural products samples were below the safety margin, indicating no effect on human health.

Application of Macroporous Diatomaceous Earth Column for Residue Analysis of Insecticide Endosulfan in Herbal Medicines

Application of Macroporous Diatomaceous Earth Column for Residue Analysis of Insecticide Endosulfan in Herbal Medicines Jeong-In Hwang, Young-Hwan Jeon, Hyo-Young Kim, Ji-Hwan Kim, Yoon-Jeong Lee, Ju-Young Park, Do-Hoon Kim and Jang-Eok Kim (School of Applied Biosciences, Kyungpook National University, Daegu 702-701, Korea, Division of Herbal Medicine Research, Korea Food and Drug Administration, Osong 363-951, Korea)

Effects of lipids on analysis of residue pesticides in herbal medicines

Serious problems in residue analysis of acetamipirid, chlorpyrifos, and bifenthrin caused by lipids present in herbal medicines, platycodon root, safflower, and persicae semen have been found during the pesticide residue analysis using a currently used analytical method. Particularly, recovery tests for artificially spiked pesticides showed poor recoveries for bifenthrin in persicae semen, which may be due to the low polarity of the pesticide and high lipid content in the matrix. An unclear layer separation between water and organic solvent, methylene chloride, has been also observed during the liquid-liquid partitioning process, which favors modification of the liquid-liquid partitioning by replacement with acetonitrile and a macroporous diatomaceous earth column, respectively. The effectiveness of newly modified methods was evaluated based on the recoveries of three pesticides in the herbal medicines at two fortification levels (1.0 and 4.0 mg/kg). The modified methods increased recoveries to 81.8–98.9%, suggesting those methods could be effective and feasible alternatives to determine acetamiprid, bifenthrin, and chlorpyrifos in lipidic samples.