• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.493-499
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• 2017

This study was conducted to monitor the current status of pesticide residues and sulfur dioxide in a total of 91 functional rice products from February to October 2016. Multi class pesticide multiresidue methods of 220 pesticides was performed by the GC/ECD, GC/NPD, GC/TOF/MS, LC/PDA, and LC/FLD. As a result of analysis, the pesticides were detected in 3 samples, representing a detection rate of 3.3%. The kind of pesticides was propiconazole and isoprothiolane used for germicide in agriculture or plant growth regulator purposes. The detected levels were 0.0340~0.0566 mg/kg, which were under the MRL (Maximum Residues Limits). The contents of sulfur dioxide in 91 samples by the Monier-Williams method were not detected. Risk assessment of pesticides evaluated using human health exposure with the ratio of EDI (Estimated daily intake) to ADI (Acceptable daily intake). %ADI (the ratios of EDI to ADI) were 0.24~1.25% with safety level.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.392-399
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• 2021

This study was conducted to research the status of pesticide residues in a total of 114 herbs and spices obtained from January to October 2020. 341 pesticide residues were analyzed by the multi class pesticide multiresidue methods using GC-MSMS, GC-ECD, GC-NPD, LC-MSMS, LC-PDA, and LC-CAS. As a result of analysis, 36 pesticide residues were found, and detection rate was 31.6%. Of them, seven samples were detected over Maximum Residue Limits (MRLs) and the unsuitable level in pesticide was 6.1%. The herbs and spices exceeding MRLs include coriander (2 times), mint (2 times), basil (once), rosemary (once), and boraye (once). According to an analysis of 341 pesticide residues, 22 pesticides were detected 52 times and 8 pesticides were found to exceed the MRLs. The pesticides exceeding MRLs were ingredients such as etofenprox, flufenoxuron, fluquinconazole, iprodione, lufenuron, paclobutrazol, phenthoate, and spiromesifen.

• Journal of Food Hygiene and Safety
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• v.37 no.4
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• pp.260-270
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• 2022

In this study, we tested for pesticide residues in 114 samples representing 20 different types of fruit circulating in Gyeonggido. A total of 341 pesticides were identified via a multi-residue method using GC-NPD, GC-ECD, GC-MSMS, and LC-MSMS. In whole fruit, pesticides were detected in 48 cases, with a concentration range of 0.0025-0.1663 mg/kg. In the peels, pesticides were detected in 85 cases, with a concentration range of 0.0026-4.7185 mg/kg and a higher average concentration than was found in whole fruit. In the pulp, pesticides were detected in 8 cases, with a concentration range of 0.0021-0.0993 mg/kg. In most of the peels, pesticides were detected below MRL. In the kiwi peel, deltamethrin (with an MRL of 0.05 mg/kg) was detected at 0.1020 mg/kg. Since MRLs are applied to whole fruit, these levels are not unsuitable for ingestion. However, washing is recommended before ingestion to promote healthier and safer inclusion of the peel in the diet. Continuous monitoring of the peel and pulp is indicated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1515-1522
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• 2008

Monitoring the pesticide residues in agricultural products is essential to protect consumers, obtain data for risk assessment, and ensure fair trade practices. We developed a multi-residue method for the analysis of 37 pesticides with different physico-chemical properties in agricultural products and analyzed the amount of pesticide residues on about 1,000 samples circulated in South Korea. The samples consisted of 26 different types of agricultural products selected at markets in 14 major cities; cereals (2 species), nuts (1 species) potatoes (1 species), beans (2 species), fruits (3 species), vegetables (16 species), and mushrooms (1 species). In this study, residual pesticides were detected in 23 samples (2.2%) and one sample was detected to be over maximum residue limits (MRLs, 0.1%) for pesticides in foods by the Korea food code. In leafy vegetables such as pepper leaves, radish leaves, cham-na-mul, shin-sun-cho, crown daisy, chwi-na-mul and citrus fruits such as kumquat, 8 kinds of pesticides were detected. Specially, diazinon were detected over MRLs and also, endosulfan, ethoprophos and phenthoate were detected frequently. Based on these results, we investigated the risk assesment from amount of residual pesticide, total %ADI was 1.262%, but the value has not effected on human health.

• The Korean Journal of Pesticide Science
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• v.17 no.3
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• pp.162-167
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• 2013

An analytical method for the simultaneous determination of pencycuron in agricultural products was established by using GC-NPD. The method was validated through the guidelines of linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision. The calibration curve of pencycuron was linear over the concentration range of 0.02-2 mg/kg with correlation coefficient of above 0.9999. The limits of detection and quantification were 0.005 and 0.02 mg/kg. Mean recoveries of pencycuron for each sample were 79.6-107.5% at the level of 0.02 mg/kg and 86.4-112.1% at the level of 0.2 mg/kg and 84.0- 104.9% at the level of 1 mg/kg. Relative standard deviation (RSD) in recoveries were all less than 5%. The intra- and inter-day precision (RSD) were 1.6-3.0% and 5.3-11.5%, respectively. The result of validation indicated that this method was accurate and sensitive assay.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.361-370
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• 2010

Considering the efficiencies of the preparation process at each stage obtained in previous studies, the analytical determination method was established for multi-pesticide residues in soils. It consist of the acetone-extraction, the dichloromethane-partition, the Florisil or silica-gel chromatography and the gas chromatography analysis equipped with the electron capture detector and the nitrogen-phosphorus detector. In the soil recovery test by Florisil clean-up system, the number of pesticides recovered in the range of 70~120% and showed less than 20% of RSD were 165 pesticides for paddy soil, 169 pesticides for upland soil and 159 pesticides in both soils through the tested 183 pesticides. And in the soil recovery test by silica-gel system, the number of pesticides recovered in the range of 70~120% and showed less than 20% of RSD were 154 pesticides for paddy soil, 145 pesticides for upland soil, and 134 pesticides in both soils.

• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.1-7
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• 2014

The present study was performed to investigate the pre-harvest residue limit (PHRL) of pesticides namely, metalaxyl-M and flusilazole in oriental melon, and to identify the biological half-life and characteristics of their residues. In this study, pesticides were sprayed once as single spray and double spray on oriental melon. The oriental melon samples were collected at 0, 1, 2, 3, 5, 7, 9 and 11 days before harvest and samples were extracted with QuEChERS method. The residues of both the pesticides were quantified using GC/NPD and LC/MS/MS. The limit of detection was found to be 0.02 mg/kg and 0.01 mg/kg and their recoveries were greater than 95% (95.7% ~ 103.2% for metalaxyl-M and 100.2% ~ 106.8% for flusilazole) for both pesticides. The biological half-lives of both metalaxyl-M and flusilazole were 12 days at single and double spray, respectively. The PHRL of metalaxyl-M and flusilazole was found 1.0 mg/kg and 0.3 mg/kg, respectively for 10 days before harvest. The results of the present study shows the residual level of both the pesticides metalaxyl-M and flusilazole in oriental melon were less than their maximum residual limits.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.195-201
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• 2012

We tested for pesticide residues in 124 samples of 22 different items of imported fruits circulated in Gyeonggido. Total 218 pesticides were analyzed by multi-residue method using gas chromatography/nitrogen phosphorus detector-electron capture detector (GC/NPD-ECD), time of flight/mass spectrometer (TOF/MS), ultra performance liquid chromatography/photo diode array (UPLC/PDA), high performance liquid chromatography/fluorescence detector (HPLC/FLD) and mass spectrometer (LC/MS/MS). The pesticides were detected in 18 fruits samples, ranging 0.003~0.3 mg/kg and no samples had violative residue. The separation test to 14 sample pesticides detected was conducted to monitor the current status of pesticide residues according to the partial characteristic. The pesticides were detected in 14 peels ranging 0.03~1.5 mg/kg and 2 fleshes in less than detection limits. These results indicate that imported fruits are safe when the human takes normally but even the small amount of pesticides is harmful when the human takes it in a prolonged period. Therefore, the pesticide residual amounts of imported friuts should be constantly monitored for food safety.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.6
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• pp.523-538
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• 2009

Recently, there has been a keen demand for real-time automatic monitoring of VOCs not only in Korea but other developed countries. We carried out this study to evaluate and to optimize the performance of a continuous automatic monitoring system for hazardous VOCs (HVOCs) in the ambient atmosphere, using an on-line GC system. The online system normally consisted of a Nafion dryer prior to a cold trap of an automatic thermal desorption apparatus and a GC system equipped with two detectors, i.e. PID and ECD. Preliminary tests conducted to check out any contamination of the system revealed an evidence of significant artifact formation of benzene, and it was found that the Nafion dryer (even brand new one) is the source of the benzene artifact. Thus, all the subsequent experiments in this study was carried out inevitably by removing the Nafion dryer. The on-line GC method was investigated with a variety of QC/QA performance criteria such as repeatability, linearity, lower detection limits, and accuracy. In order to find out the best operating condition for the on-line GC system, three different types (in terms of adsorption strength) of cold trap combinations were tested, i.e. (i) Tenax-TA and Carbopack-B combination (weak and hydrophobic); (ii) Tenax-TA, Carbopack-X and Carboxen-1000 combination (strong and hydrophilic); and (iii) Tenax-TA and Carbopack-X combination (medium and hydrophobic/hydrophilic). The USEPA TO-17 manual method was selected as a reference method to evaluate the performance of the on-line method. A series of experiments revealed that the system performance was superior to others when a cold trap packed with hydrophilic adsorbents (Tenax-TA/Carbopack-X/Carboxen-1000 combination) was used and operated at $25^{\circ}C$. However, the system with a cold trap packed with a combination of Tenax-TA and Carbopack-X is more recommended for field applications since the carboxen-1000 adsorbent is too sensitive to water vapor, and hence the performance of the system might be very unstable to humid samples or during rainy days. Furthermore, the precision and accuracy criteria of the Tenax-TA/ Carbopack-X combination were generally compatible with the triple adsorbents cold trap. The continuous automatic monitoring method is, thus, considered very useful to real-time monitoring to understand the variations of VOCs concentrations in ambient air, as it adopts much simpler procedures in sampling, analysis, and data integration steps than manual monitoring methods. However, it should be noted that there is a high possibility of benzene artifacts formation through the Nafion dryer, which is often installed to remove water vapor in air samples before being adsorbed onto the cold trap. Therefore, if a Nafion dryer is used in any studies of monitoring VOCs, the benzene contamination should be carefully examined before carrying out obtaining the data.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.237-245
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• 2007

We tested for residual pesticide levels in agricultural products purchased from 5 provinces within the middle region of Korea during 2006. A Total of 488 samples of 23 different types of agricultural products were analyzed by GC/MS, GC-NPD, and LC/MS/MS. We used multi-analysis methods to analyze for 231 different pesticide types; a single residual pesticides were detected in 92 samples (18.9%), of which 9 samples (1.9%) exceeded the Korea Maximum Residue Limits (MRLs). we detected pesticide residue in more than 50% of the pepper leaf and welsh onion samples. For the welsh onions, 16 among the 30 analyzed samples contained pesticide residue, and 4 samples exceeded the Korea MRLs. Among the 234 kinds of pesticides we tested for, 42 were detected, and 21 of them were detected more than twice. Six pesticide residue types, including cypermethrin, iprodione, fludioxonil, ethoprophos, flutolanil, and lufenuron, exceeded the MRLs. No residual pesticides were detected in 396 of the samples (81.1%), and the residual pesticide levels in 83 samples (17.0%) were lower than the Korea MRLs, indicating that 98.1% of the samples were relatively safe.