• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.902-908
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• 2010

In 2008, we monitored residual pesticides of 15 agricultural products such as rice, corn, pea, chestnut, mandarin, lemon, onion, pineapple, lettuce, chard, sweet potato stalk, burdock, squash, sweet pepper and mushroom. Agricultural commodities were collected from markets in 22 provinces (Seoul, Busan, Incheon, Daegu, Ulsan, Daejeon, Gwangju, Wonju, Pohang, Gumi, Changwon, Gimhae, Suwon, Seongnam, Bucheon, Goyang, Yongin, Cheongju, Cheonan, Jeonju, Yeosu, and Jeju). Total 48 pesticides were analysed by multi-residue method using GC/MS/MS. We analysed 1,064 samples and 34 samples (3.20%) were detected. Sweet potatostalk, burdock, chestnuts, peas, corn, chard, squash, mushroom and onions were found to be free from pesticide residues. 6 other agricultural products did not exceed MRLs (Maximum Residue Limits) by the Korean Food Code. Chloropyrifos and fenobucarb were particularly prevalent and also they were detected over 10 times in this monitoring. Nonetheless, the exposed quantity of the 7 residual pesticides is to be considered relatively safe, compared with the acceptable daily intake (ADI) of residual pesticides.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.61-69
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• 2013

BACKGROUND: This survey was done to investigate the pesticide residues and to assess their risk on agricultural products on the Markets in Incheon from 2010 to 2012. METHODS AND RESULTS: The total number of samples were 16,025 for agricultural products and these were analyzed by multi-residue method using GC-ECD/NPD, GC-MS, LC-MS/MS and HPLC-PDA/FLD. The violation rates of the samples over maximum residue limits(MRLs) of pesticide residues established by Korean Food and Drug Administration in the survey of 2010, 2011 and 2012 were 1.2%, 0.8% and 0.7%, respectively. CONCLUSION(S): Of the total violated samples, more than 75% of the rates were recorded from the samples of leafy vegetables. Most commonly encountered agricultural commodities over MRLs were Chwinamul, perilla leaves and crown daisy. The pesticides detected yearly over MRLs during three years were endosulfan, chlorpyrifos, diazinon, lufenuron, chlorothalonil, flutolanil, procymidone, ethoprophos. Estimated daily intakes compared to acceptable daily intakes, except radish and Welsh onion, is estimated less harm on human in 10 kinds of pesticides which frequently occurred violation.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.209-218
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• 2010

There experiment were carried out to analyze for pesticide residues in 4 kinds of dried fruits collected in northern area of Seoul in 2007~2009. Total of 213 samples were analyzed. According to the results, 20 kinds of residual pesticides were detected. Residual pesticides were detected in 66 samples (31.0%) and 8 samples (3.8%) exceeded maximum residue limits (MRL). Cypermethrin, fenvalerate, endosulfan, chlorpyrifos, bifenthrin were detected frequently. The Pesticide types which were detected in dried furits were revealed in order of pyrethroid > organophosphate > organochloride > dicarboximide. Detection rates of dried fruits were dried chinese matrimony vein (53.0%), dried jujube (34.9%), dried rubi fructus (7.6%) and dried maximowiczia chinensis (4.6%). Based on these results, we investigated the risk assessment from amount of residual pesticide in dried jujube. Range of %ADI were 0.0001~0.0081%, but the value has not effected on human health.

• Journal of Food Hygiene and Safety
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• v.35 no.2
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• pp.109-117
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• 2020

This study aimed to develop an analytical method for determination of 18 dyes in livestock and fishery products by liquid chromatograph-tandem mass spectrometry (LC-MS/MS). The developed method was validated for linearity, accuracy, limit of quantifications (LOQ) and recovery based on the CODEX guideline (CAC/GL-71). Target matrices (beef, pork, chicken, egg, milk, flatfish, eel, and shrimp) were extracted using acetonitrile (containing 1% of acetic acid) and then, purified with C₁₈ and primary secondary amine (PSA). Calibration linearity was obtained (r²>0.98) and LOQs were 0.002 mg/kg in animal products. The recoveries of dyes were ranged from 63 to 112% and relative standard deviations (RSDs, %) were less than 15%. The residues of 18 dyes were investigated in real samples (n=124) collected from retail markets in South Korea. As a result, a total of seven samples showed positive results for target analytes in fish samples. However, there was no violation according to the maximum residue limits set by the Korean Food Code. The proposed method will be used for routine analysis of dye residues in livestock and fishery products.

• The Korean Journal of Pesticide Science
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• v.9 no.3
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• pp.237-242
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• 2005

This experiment was carried out to develop the fast and simple method for pesticide residue analysis by using solvent free solid injector (SFSI) and to validate the efficiency of the method developed for the residue analysis of the endocrine disruptor-like pesticides such as endosulfan, metribuzin, trifluralin and vinclozolin. The samples after freeze drying were sealed in glass capillary tubes and then introduced into the heated injector of gas chromatogaphy. The required pre-heating times were 1 min for endosulfan and trifluralin, 5 min for vinclozolin, and 10 min for metribuzin. The detection limits of endosulfan in chinese cabbages, metribuzin in lettuces, trifluralin in spinachs and vinclozolin in hot peppers were 0.05, 0.1, 0.05 and 0.05 ng, respectively and their recoveries were ranged from 74%, $98{\sim}107%$, $86{\sim}95%$ and $94{\sim}95%$, respectively. The detected level of metribuzine residue in field lettuce samples by using the SFSI was 0.6 ng/mg.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.75-82
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• 2020

BACKGROUND: This study was carried out to establish pre-harvest residue limits (PHRLs) of indoxacarb and pymetrozine in broccoli under greenhouse conditions, based on dissipation patterns and biological half-lives of pesticides during 10 days after application. METHODS AND RESULTS: The field studies were conducted in two different greenhouse, located in Chungju-si (Field 1) and Gunsan-si (Field 2). Samples were collected at 0, 1, 2, 3, 5, 7 and 10 days after spraying pesticide suspension. The analytical methods for indoxacarb and pymetrozine using HPLC-DAD were validated by recoveries ranging of 94.3-105.4% and 81.8-96.0%, respectively, and MLOQ (Method Limit of Quantification) of 0.05 mg/kg. Biological half-lives of indoxacarb and pymetrozine were 2.9 and 3.2-3.8 days in broccoli, respectively. The lower 95% confidence intervals of dissipation rate constant of indoxacarb were determined as 0.1508 (Field 1) and 0.2017 (Field 2), whereas those of pymetrozine were calculated as 0.1489 (Field 1) and 0.1577 (Field 2). CONCLUSION: The significant differences were not observed between the dissipation rates of indoxacarb and pymetrozine in broccoli. The major factor affecting residue dissipation was the dilution effect by fast growth. The PHRLs for 10 days prior to harvest were recommended as 30.06 (Field 1) and 18.07 (Field 2) mg/kg for indoxacarb, and 4.84 (Field 1) and 4.43 (Field 2) mg/kg for pymetrozine, respectively.

• Food Science and Preservation
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• v.21 no.1
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• pp.69-74
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• 2014

We tested for residual pesticide levels in school foodservice agricultural products in Seoul, Korea from 2010 to 2012. A total of 316 samples of 23 different types of agricultural products were analyzed via gas chromatography-nitrogen phosphate detector (GC-NPD), an electron capture detector (GC-${\mu}ECD$), a mass spectrometry detector (GC-MSD), and a high performance liquid chromatography-ultraviolet detector (HPLC-UV). We used multi-analysis methods to analyze 185 different pesticide types. Among the selected agricultural products, residual pesticides were detected in 26 samples (8.2%), of which 6 samples (1.9%) exceeded the Korea Maximum Residue limits (MRLs). We detected pesticide residue in more than 65% of the Chwinamul, while 6 among 9 analyzed samples contained pesticide residue, and 1 sample exceeded the Korea MRLs. Among the 185 kinds of pesticides that we have tested, 18 were detected, while 7 of them were detected more than twice. Data obtained were then used for estimating the potential health risks associated with the exposures to these pesticides. The most critical commodity is carbofuran in the perilla leaves, which has contributed 3.8% to the hazard index (HI). These results showed that the detected pesticides could not be considered as a serious public health problem. Nevertheless, constant supervision is recommended.

• 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.7 no.1
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• pp.14-20
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• 1988

The effect of polyethylene film(P.E.) mulching on the degradation of alachlor(N-methoxymethyl-2, 6-diethyl ${\alpha}-chloroacetoanilide$), pendimethalin(3, 4-dimethyl-2, 6-dinitro-N-l-ethylpropylanilide) and diphenamid(N,N-dimethyl-2, 2-diphenylacetamide) in red pepper, peanut, and sesame fields was investigated. In soils under the non-mulching condition the half-lives of alachlor, pendimethalin and diphenamid were 3, 37 and $24{\sim}46$ days, respectively. However, the half-lives of those under the P.E. mulching condition were longer than under the non-mulching condition. The differences in the half-lives between P.E. mulching and non-mulching conditions were about 30 days for pendimethalin and from 20 to 90 days for diphenamid. However, the half-life of alachlor was hardly affected by P.E. mulching. Pendimethalin and alachlor were not detected in the harvasted red peppers, peanuts and sesame under P.E. mulching and non-mulching conditions. But, the residue of diphenamid in peanuts was 0. 147 ppm under the P.E. mulching condition and 0.071 ppm under the non-mulching condition, and the residue of diphenamid in sesame was 0.022 ppm under the P.E. mulching condition and 0.129 ppm under the non-mulching condition. The amounts, however, were below the tolerance limits for pesticide residue.

• Polymer(Korea)
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• v.32 no.2
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• pp.125-130
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• 2008

A commercial cyclic diphosphonate ester (TPMP) and melamine (MA) was combined and added to polyamide 6 (PA6) to prepare the fire retardant PA6. An increase of the oxygen index to 28.6 as well as an improvement of the UL-94 classification to V-0 rating was observed. Cone measurements explained the rate of heat release (RHR) decreased and TGA showed the early decomposition and high solid residue due to co-addition of TPMP and MA, suggesting the occurrence of synergistic effect of TPMP and MA on fire resistance of PA6. The morphology of the char developed during combust ion showed the appearance of thick, intumescent cells on the surface of retardant PA6, which protects the underlying material from the action of the heat flux or flame and limits the diffusion of combustible volatile products towards the flame and oxygen.