• 한국환경농학회지
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• 제2권2호
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• pp.83-89
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• 1983

우리나라 주요(主要) 하천수(河川水)에 대(對)한 농약잔유실태(農藥殘留實態)를 파악(把握)하여 농약안전사용(農藥安全使用)의 기초자료(基礎資料)로 활용(活用)코자 5대강(大江) 본류(本流)를 중심(中心)으로 주요(主要) 지류유입지점(支流流入地點)을 강별(江別)로 5개소(個所)를 선정(選定), 갈수기(渴水期)(4월(月))와 성수기(盛水期)(8월)에 동일(同一) 지점(地點)에서 시과(試科)를 채취(採取)하여 하천수중(河川水中) 농약잔유량(農藥殘留量)을 조사(調査)하였다. 조사대상지역(調査對象地域)이나 조사시기(調査時期)와는 무관(無關)하게 하천수중농약잔유량(河川水中農藥殘留量)은 극미량(極微量)으로 검출(檢出)되었다. 대체(大體)로 성수기(盛水期)가 갈수기(渴水期)에 비(比)해 다소(多少) 높은 수준(水準)으로 검출(檢出)되었는데, IBP와 diazinon의 경우는 그러한 현상(現象)이 더욱 현저하였다. 유기인계농약(有機燐系農藥)은 IBP와 diazinon만이 검출(檢出)되었으며, fenthion, fenitrothion, chlorpyriphos, chlorpyriphos-methyl, chlorfenvinphos, phenthoate, 및 edifenphos는 어느 시료(試料)에서도 검출(檢出)되지 않았다. IBP와 diazinon의 조사최고치(調査最高値)는 각각(各各) 1.53과 0.39ppb이었다. 유기염소농약(有機鹽素農藥)은 조사시기(調査時期)에 따른 차리(差異)가 거의 없었다. Aldrin은 어느 시료(試料)에서도 검출(檢出)되지 않았으며, dieldrin과 p.p`-DDT는 극(極)히 일부(一部) 시료(試料)에서만 극미량(極微量)으로 검출(檢出)된 반면(反面), BHC와 heptachlor및 ${\alpha}-endosulfan$의 검출빈도(檢出頻度)는 다소(多少) 높은 편(便)이나 그들의 잔류수준(殘留水準)은 매우 낮았다.

• Molecules and Cells
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• 제40권4호
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• pp.299-306
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• 2017

The transcriptional activator AphB has been implicated in acid resistance and pathogenesis in the food borne pathogens Vibrio vulnificus and Vibrio cholerae. To date, the full-length AphB crystal structure of V. cholerae has been determined and characterized by a tetrameric assembly of AphB consisting of a DNA binding domain and a regulatory domain (RD). Although acidic pH and low oxygen tension might be involved in the activation of AphB, it remains unknown which ligand or stimulus activates AphB at the molecular level. In this study, we determine the crystal structure of the AphB RD from V. vulnificus under aerobic conditions without modification at the conserved cysteine residue of the RD, even in the presence of the oxidizing agent cumene hydroperoxide. A cysteine to serine amino acid residue mutant RD protein further confirmed that the cysteine residue is not involved in sensing oxidative stress in vitro. Interestingly, an unidentified small molecule was observed in the inter-subdomain cavity in the RD when the crystal was incubated with cumene hydroperoxide molecules, suggesting a new ligand-binding site. In addition, we confirmed the role of AphB in acid tolerance by observing an aphB-dependent increase in cadC transcript level when V. vulnificus was exposed to acidic pH. Our study contributes to the understanding of the AphB molecular mechanism in the process of recognizing the host environment.

• 한국환경농학회지
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• 제35권1호
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• pp.6-14
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• 2016

BACKGROUND: Residual organochlorine pesticides (OCPs) are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effect to human health and the environment. They were designated as persistent organic pollutants (POPs) by Stockholm Convention. Greenhouse strawberry is economic crop in agriculture, and its cultivation area and yield has been increased. Therefore, we tried to investigate the POPs residue in greenhouse soil and strawberry.METHODS AND RESULTS: Extraction and clean-up method for the quantitative analysis of OCPs was developed and validated by gas chromatography (GC) with electron capture detector (ECD). The clean-up method was established using the modified quick, easy, cheap, effective, rugged, and safe(QuEChERS) method for OCPs in soil and strawberry. Limit of quantitation (LOQ) and recovery rates of OCPs in greenhouse soil and strawberry were 0.9-6.0 and 0.6-0.9 μg/kg, 74.4-115.6 and 75.6-88.4%, respectively. The precision was reliable sincerelative standard deviation (RSD) percentage (0.5-3.7 and 2.9-5.2%) was below 20, which was the normal percent value. The residue of OCPs in greenhouse soil was analyzed by the developed method, and dieldrin, β-endosulfan and endosulfan sulfate were detected at 1.6-23, 2.2-28.4 and 1.8-118.6 μg/kg, respectively. Those in strawberry were not detected in all samples.CONCLUSION: Dieldrin, β-endosulfan and endosulfan sulfate in a part of investigated greenhouse soil were detected. But those were not detected in investigated greenhouse strawberry. These results showed that the residue in greenhouse soil were lower level than bioaccumulation occurring.

• 농약과학회지
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• 제15권1호
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• pp.22-27
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• 2011

계면활성제인 4-alkylphenol polyethoxylate는 한국 등 여러 국가에서 매우 광범위하계 사용되어 왔으나 이들 화합물 및 분해산물이 최근 내분비계에 장애를 일으키는 환경호르몬 물질로 분류됨에 따라 농약 등의 첨가물로 사용가능한 nonylphenols(NPs)에 대한 잔류 연구가 매우 활발하게 진행되고 있다. 본 연구에서는 극미량 정밀 잔류분석기술이 필요한 nonylphenols에 대하여 분석용매 몇 정제용 카트리지 선정에 필요한 전처리기술에 대해 보고하고자 한다. 분석 결과에 따르면, HPLC등급의 용매이라 할지라도 $Et_2O$의 경우 100배 농축 용매에서 NPs가 검출되어 시료 분석 시 방해요인으로 작용하였으며, 이의 제거를 위해 $CaH_2$를 사용한 증류 후 사용법을 개발하였다. 또한, 시료정제용 카트리지는 silica gel 및 Florisil 제품군, 그리고 glass ware과 plastic ware로 나누어 카트리지 내 nonylphenols 잔류량을 분석한 결과 silica gel 제품군 glass ware 제품이 전처리 정제용으로 적합한 것으로 확인되었다.

• 한국환경농학회지
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• 제19권3호
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• pp.259-269
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• 2000

식품원료인 농수축산물은 생산측면과 소비측면에서 각각 관행적으로 분류되어 사용되어 왔다. 한편 식품원료 중 잔류농약, 가축의약품, 환경오염물질과 같은 화학잔류물의 기준설정 및 규제를 위해서는 잔류가능성을 감안한 분류방식이 요구되고 있으나 식품원료의 분류방식이 통일되지 못하여 많은 혼란을 가져왔다. 본 연구에서는 농산물 중 농약잔류 허용기준을 적용하는데 있어서 국내외적으로 나타난 문제들을 지적하였으며 국제식품규격위원회의 Codex 기준을 무난히 수용할 수 있는 농수축산물 분류방식을 제시하였다. 이와 아울러 여기에서 제시한 분류법을 이용하여 잔류농약을 비롯한 다른 화학물질의 오염기준을 설치할 경우의 고려할 점을 제시하였다.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1760-1772
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• 2006

Mature acetylcholinesterase (AChE) gene (gm, 1,836 bp) was cloned from the housefly and successfully expressed in the E. coli CodonPlus (DE3) RIL system (GM-E, 72 kDa) with a yield of 1,630 mU/g fresh cells. Using the gm, 10 kinds of mutants were constructed and expressed for enhancing sensitivity to insecticides. The sensitivity of these mutants to five kinds of organophosphate (OP) and three carbamate insecticides was investigated by measuring the apparent bimolecular inhibition constant ($k_i=k_2/K_d$). Surprisingly, the sensitivity of quadruple mutant IGFT was enhanced as much as 7-fold for acephate, 164-fold for demeton-S-methyl, 484-fold for dichlorvos, 523-fold for edifenphos, 30-fold for ethoprophos, 30-fold for benfuracarb, 404-fold for carbaryl, and 107-fold for furathiocarb, compared with that of GM-E, although the sensitivity of each single point mutant was slightly increased. These mutational studies indicated that (i) contradictory to Walsh et al. [39], the residue 327 is the important key residue for enhancing sensitivity as much as the residue 262, (ii) the residue 82 and additional residues of 234, 236, and 585 are also important, and (iii) sensitivity was cooperatively accelerated as the number of strategic mutations increased.

• 한국환경농학회지
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• 제30권4호
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• pp.357-366
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• 2011

BACKGROUND: Mathematical model such as GLEAMS have been developed and successfully applied to upland fields to estimate the level of pesticide residues in soil. But, the GLEAMS model rarely applied to the Korean conditions. METHODS AND RESULTS: To evaluate pesticide transport in soil residue using the GLEAMS model from pepper plot, Alachlor, Endosulfan, Cypermethrin and Fenvalerate were applied for standard and double rate. Soil sampling was conducted and decaying patterns of pesticides were investigated. Observed climate data such as temperature and irrigation amount were used for hydrology simulation. The observed pesticide residue data of 2008 were used for parameter calibration, and validation of GLEAMS model was conducted with observed data of 2009. After calibration, the $K_{oc}$ (Organic carbon distribution coefficient) and WSHFRC (Washoff fraction) parameters were identified as key parameters. The simulated concentrations of the pesticides except Fenvalerate were sensitive to $K_{oc}$ parameter. Overall, soil residue concentrations of Alachlor, Cypermethrin and Fenvalerate were fairly simulated compared to those of Endosulfan. The applicability of the GLEAMS model was also confirmed by statistical analysis. CONCLUSION(s): GLEAMS model was eligible for evaluation of pesticide soil residue for Alachlor, Cypermethrin and Fenvalerate.

• 한국약용작물학회지
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• 제28권6호
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• pp.435-444
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• 2020

Background: As the Positive List System (PLS) is implemented in broad application to agricultural products, attention to the correct use of pesticides is also needed in the production of mulberry leaves and fruit. In this regard, three types of pesticides against mulberry popcorn disease were applied 2 - 3 times both in the field and greenhouses to prepare safety standards. Residual pesticide analysis was conducted on mulberry fruits and leaves. Methods and results: Three pesticieds, thiophanate-methyl, thiophanate-methyl·triflumizole and fluopyram registered as PLS pesticides for mulberry popcorn disease, were sprayed in the Wanju and in Buan regions, after which residual pesticide analysis was conducted using high-performance liquid chromatography (HPLC). As three pesticieds were either undetected or below the permissible level in mulberry fruit, demonstrating that they were suitable for safe spraying. However, 5.6 mg/kg of thiophanate-methyl was detected in the greenhouse after three application, which was slightly above maximum residue limit (MRL). Furthermore the level of thiophanate-methyl·triflumizole was higher than 0.2 mg/kg ("Gwasang No. 2" variety, spraying twice) or similar to 0.09 mg/kg ("Daesim" variety, spraying thrice) the permissible level (0.1T mg/kg) as the thiophanate-methyl was detected in mulberry leaves in the greenhouse. Conclusions: The spraying frequency for controlling mulberry popcorn disease in greenhouses should be limited to two times or less, especially when mulberry leaves are treated with thiophanate-methyl·triflumizole careful consideration is required if the leaves are to be used as food materials.

• Asian-Australasian Journal of Animal Sciences
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• 제14권3호
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• pp.402-413
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• 2001

Food safety is a term broadly applied to food quality that may adversely affect human health. These include zoonotic diseases and acute and chronic effects of ingesting natural and human-made xenobiotics. There are two major areas of concern over the presence of residues of antibiotics in animal-derived foodstuffs with regard to human health. The first is allergic reactions. Some antibiotics, such as penicillins can evoke allergic reactions even though small amounts of them are ingested or exposed by parenteral routes. The second is development of antibiotic resistance in gut bacteria of human. Recently multi-resistant pneumococcal, glycopeptide-resistant enterococci and gram negative bacteria with extended-spectrum $\beta$-lactamases have spread all over the world, and are now a serious therapeutic problem in human. Although it is evident that drugs are required in the efficient production of meat, milk and eggs, their indiscriminate use should never be substituted for hygienic management of farm. Drug should be used only when they are required. In addition to veterinary drugs, environmental contaminants that were contaminated in feed, water and air can make residues in animal products. Mycotoxins, heavy metals, pesticides, herbicides and other chemicals derived from industries can be harmful both to animal and human health. Most of organic contaminants, such as dioxin, PCBs and DDT, and metals are persistent in environment and biological organisms and can be accumulated in fat and hard tissues. Some of them are suspected to have endocrine disrupting, carcinogenic, teratogenic, immunodepressive and nervous effects. The governmental agencies concerned make efforts to prevent residue problems; approval of drugs including withdrawal times of each preparation of drugs, establishment of tolerances, guidelines regarding drug use and sanitation enforcement of livestock products. National residue program is conducted to audit the status of the chemical residues in foods. Recently HACCP has been introduced to promote food safety from farm to table by reducing hazardous biological, chemical and physical factors. Animal Production Food Safety Program, Quality Assurance Programs, Food Animal Residue Avoidance Databank are para- or non-governmental activities ensuring food safety. This topic will cover classification and usage or sources of chemical residues, their adverse effects, and chemical residue status of some countries. Issues are expanded to residue detection methodologies, toxicological and pharmacokinetic backgrounds of MRL and withdrawal time establishments, and the importance of non-governmental activities with regard to reducing chemical residues in food.

• 농약과학회지
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• 제15권2호
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• pp.149-159
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• 2011

HPLC-UVD/MS를 이용하여 농산물 중 benzothiadiazole계 선택적 접촉 제초제인 bentazone의 잔류분석법을 확립하였다. 농산물 시료에 인산용액으로 pH를 1로 조절한 acetone을 가하여 추출하였고, bentazone의 잔류분은 dichloromethane 액-액 분배법과 florisil 흡착크로마토그래피법으로 정제하여 분석대상 시료로 하였다. Bentazone의 정량적 분석을 위한 최적 HPLC 분석 조건을 확립하였고, $C_{18}$ 칼럼을 이용한 HPLC 분석 시 불순물의 간섭은 없었으며, 대표 농산물 중 bentazonc의 분석정량한계(LOQ)은 0.02 mg/kg 이었다. 전체 농산물에 대해 정량한계, 정량한계의 10배 및 50배 수준에서 회수율을 검토한 결과 모든 처리 농도에서 82.0~97.9% 수준을 나타내었으며, 농산물 시료 및 처리수준에 관계없이 10%미만의 분석오차를 나타내어 잔류분석 기준이내를 만족하였다. 본 연구에서 확립한 benzothiadiazole계 제초제인 bentazone의 잔류분석법은 검출한계, 회수율 및 분석오차 면에서 국제적 분석기준을 만족할 뿐만 아니라, LC/MS SIM을 이용한 잔류분의 재확인과정 및 회수율 검증의 결과를 종합해 볼 때 분석과정의 편이성 및 신뢰성이 확보된 공정분석법으로 사용이 가능 할 것으로 판단된다.