• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.192-202
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• 2010

Pesticide residues were investigated in 16 commodities (rice, foxtail millet, buckwheat, kidney bean, peanut, sesame, orange, grapefruit, kiwifruit, spinach, perilla leaves, leek, garlic stem, garlic, ginger and oak mushroom) collected from 22 provinces (Seoul, Busan, Incheon, Daegu, Daejeon, Gwangju, Ulsan, Suwon, Seongnam, Goyang, Bucheon, Yongin, Cheongju, Jeonju, Jeju, Cheonan, Changwon, Pohang, Gumi, Jinju, Wonju and Yeosu) in 2009. Pesticides (172 kinds) were analyzed using multiresidue method by GC/MS/MS from 510 samples, and phenthoate in kiwifruit was violated by exceeding MRL. The intake assessment for 24 kinds of pesticide residues including the detected pesticides at multi pesticide residue monitoring (bifenthrin etc.) were carried out. The result showed that the ratio of EDI (estimated daily intake) to ADI (acceptable daily intake) was 0.000007~0.458% which means that the detected pesticide residues were in a safe range so that residual pesticides in the agricultural products in Korea.

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.1-8
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• 2021

The inverted Y-shaped strip detection method based on acetylcholinesterase (AChE) was developed for the rapid detection of organophosphorus and carbamate pesticides. The inactivation of AChE by organophosphorus and carbamate pesticides has been well known. The AChE catalyzes acetylthiocholine into thiocholine having (-) and (+) charges, and the (+) charge results in aggregation of gold nanoparticle (GNP). Malaoxon and carbofuran were used as standard organophosphorus and carbamate for the development of the inverted Y-shaped strip, respectively. In order to optimize the method, various angles of the Y-shaped strip, different types of nitrocellulose membrane, and concentration of AChE were tested as key parameters. The detection limit of the method was 10 ng/mL for both malaoxon and carbofuran pesticides. No cross-reaction was observed to other pesticides such as atrazine, cyanazine, simazine, bifenthrin, boscalid, metalaxyl, and chlorobenzilate. Recoveries from lettuce spiked when known concentrations of malaoxon and carbofuran were found ranging from 96.4 to 100.7% and 81 to 112.7%, respectively. This study suggests that the inverted Y-shaped strip method based on AChE may be a useful tool for the sensitive, specific, rapid detection of organophosphorus and carbamate pesticides in agricultural products.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.152-157
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• 2023

This study was aimed to investigate pesticides residue levels in nuts and seeds distributed in Gyeonggi-do. We investigated nuts and seeds in 131 products, which is pumpkin seeds (n=17), sunflower (n=12), sesame (n=23), perilla (n=11), peanut (n=18), almond (n=8), chestnut (n=6), walnut (n=14), pine nut (n=3), pecan (n=4), macadamia (n=3), brazil nut (n=5), cashew nut (n=4) and ginkgo nut (n=3). As a result of evaluating 339 pesticide residues, eight out of 131 samples were detected at the range of 0.01-0.07 mg/kg. Additionally, 7 out of 8 detected samples exceeded MRLs (Maximum Residue Limits) and 85% of them were imported. Pyraclostrobin applied on the positive list system (PLS) was detected in five Chinese pumpkin seeds samples, and the range was 0.02-0.04 mg/kg. In Indian and Korean sesame seeds, pendimethalin, boscalid, and bifenthrin were detected at 0.04, 0.05, and 0.06 mg/kg, respectively. The ratio of estimated daily intake (EDI) to acceptable daily intake (ADI) was 0.002-0.372%, indicating that the risk level was safe.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.99-106
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• 2006

Chlorothalonil and imidacloprid sprayed onto the green peppers were degraded more faster at outdoor than in greenhouse. These results were affected by dew and photodegration, considering no rain during the experimental period. Chlorothalonil, esfenvalerate and imidacloprid in green pepper, green twist pepper and sweet pepper did not show any residual pattern, because green peppers are one of the continuous harvesting crops and pesticides could not be sprayed homogeneously on them. When green peppers were pickled with soy sauce and green twist peppers were fried with vegetable oil, the amounts of pesticides such as alpha-cypermethrin, bifenthrin, chlorfenapyr, esfenvalerate and imidacloprid were diminished to the levels of about $30{\sim}71$ and $20{\sim}41%$, respectively. Esfenvalerate and imidacloprid could not be detected in 2 month-old hot pepper paste. The removal rates of pesticide residues in leaves of green peppers were about $22{\sim}37%$ by washing, about $74{\sim}95%$ by parboiling, and about $17{\sim}55%$ by drying after parboiling.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.149-156
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• 2014

The resistance levels of the green peach aphid, Myzus persicae (Sulzer), against 10 insecticides was checked and selected the applicable insecticide resistance markers. We conducted our study in 5 cabbage cultivation regions (Pyeongchang, Hongcheon, Bongwha, Muju, and Jeju) of Korea, over 3 successive years (2009-2011). We selected a multi-resistant (MR) strain from among the 5 field-collected populations. We analyzed esterase over-expression and mutation(s) in the target sites, by using native isoelectric focusing (IEF) and quantitative sequencing (QS). We detected esterase over-expression and StoF mutation in the acetylcholinesterase 1 gene (ace1) in all of the field-collected populations, including the MR strain. We did not detect the LtoF mutation, which is a well-known knockdown resistance (kdr) mutation in the para-type sodium channel gene (para), in the MR strain; however, the value of the MR strain for bifenthrin was 3,461-fold higher than that of the susceptible strain. Our results indicate that insecticide resistance is more effectively evaluated using molecular markers than by conducting a bioassay. The molecular markers StoF in ace1 and MtoL in para can easily be applied in diagnostic methods such as QS or PCR amplification of specific alleles (PASA). These methods may be extended to management of M. persicae resistance in the field.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.6.2-6
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• 1979

Foreing bodies of the esophagus and tracheobronchus are likely to occur whenever a child places an inedible object in the mouth and are common in the older age group particularily in edentulous individuals or preexisting disease. Our department had already reported the statistical survey at first in 1954, successively in 1962, 1963 and 1968, respectively according to the age, sex, variety of foreign bodies, location and duration of the lodgement. Now, we have experienced the new 186 cases during the consecutive 5 year period from January 1973 to December 1977 and reported as a 5th report comparing with previous report. The results were as follows. 1. In the incidence of foreign bodies, coins were the most common and pointed metal, disc, bony fragment were followed in order in the esophagus while the peanut and corn were common in the air passage. 2) 79 cases (56.4%) were males and 61 cases (43.6%) were females in the esophagus, which was not a significant difference to note. But in the air passage, males accounted for 33 cases (71.7%) compared to 13 cases (28.3%) of females. 3) In the aspect of age incidence, child 10 years or under accounted for almost all cases in the esophagus as well as in the air passage. 4) In the location of foreign bodies in the esophagus, the first narrowing was the most common, while in the air passage right bronchus had a high incidence but the difference of incidence between right bronchus and left bronchus was not remarkable. 5) The duration of lodgement was 24 hours or less in more than half of the all cases. 6) In the aspect of kind of coin, 10 won coins accounted for majority of the cases (67.0%) but the incidence of 100 won coins were tend to increase gradually in these years.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.141-147
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• 2008

Globally Harmonized System (GHS) for classification and labelling will provide an internationally agreed hazard classification system of chemical products and for communication of those hazards. This study aimed for establishment of the oral acute toxic class (ATC) method and application of GHS on pesticides. The ATC method was developed for determining $LD_{50}$ estimates of chemical substances with significantly fewer animals than needed when applying conventional $LD_{50}$ tests. We carried out $LD_{50}$ test and ATC test on 13 pesticides, Although methidathion EC and parathion-ethyl EC showed significantly different in $LD_{50}$ values between $LD_{50}$ test and ATC method, there are no difference in toxicity class by GHS. Both tests on the other pesticides showed almost equal results and toxicity class by GHS. Therefore, this study indicated high possibility of application of ATC method and GHS on pesticides.