• Title/Summary/Keyword: residue study

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Study of Pyrolysis Pattern and Transfer Rate of Organochlorine Pesticide in Tobacco

  • Min, Hye-Jeong;Jang, Seok-Su;Kim, Ick-Joong;Kim, Yong-Ha;Min, Young-Keun
    • Journal of the Korean Society of Tobacco Science
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    • v.29 no.2
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    • pp.118-124
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    • 2007
  • GRLs(Guidance Residue Levels) of agricultural chemicals for tobacco are recommended by the CORESTA Agro-Chemical Advisory Committee guide. In the GRLs list, organochlorine group is one of pesticides commonly used on tobacco cultivation. In this model study, the quantitative correlation in the transfer rate of pesticide residue into tobacco smoke by spiking of organochlorine pesticides to cigarette and pyrolysates were investigated. The spiking concentration referred to the range of GRLs list and the organochlorine pesticides in mainstream smoke were analyzed by GC-MS. For the understanding of the composition variation versus temperature, the behavior of pesticides was investigated by pyrolysis-gas chromatography-mass spectrometry(Py-GC-MS). In this study, the transfer rate of pesticide residue into tobacco smoke at four different spiking concentration and the composition of pyrolysates were analyzed differently. At $10\;{\mu}g/cig$ spiking concentrations, the organochlorine pesticides were transferred into tobacco smoke in $0.02\;{\sim}\;10.19\;%$ each of component and the most of pesticides were pyrolyzed during smoking. It was found that the decomposition compounds from organochlorine pesticides were mainly composed of oxygenated and nitrogenous compounds. This study could estimate that the transfer rate of pesticides into tobacco smoke is very small amount.

A Study on the Risk of Pesticide Exposure by Food Intake (식이섭취를 통한 농약폭로의 위해도에 관한 연구)

  • 전옥경;이용욱
    • Journal of Food Hygiene and Safety
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    • v.14 no.2
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    • pp.201-215
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    • 1999
  • Limited information is available on the acceptability of Korean MRLs(maximum residue limits) and the health risk based on the pesticide exposure by food intake. The aim of this study was to evaluate TMDI(theoretical maximum daily intake) and EDI(estimated daily intake) for Korean by using MRLs, food intake, residue data, and correction factors, and compare with ADI(acceptable daily intake) in order to estimate the health risk based on the pesticide exposure. The study was performed in three steps. In the frist step, the residual pesticides in each category of food were investigated using the pesticide residue analytical data(1995-96) from officially approved organizations and the analytical data for poultry was adopted from Korean food code method. In the second step, TMDI was estimated from MRLs and food factors, and was compared with ADI. In the third step, the effectiveness of each culinary treatment (washing, peeling, steaming, boiling, and salting) was evaluated and EDI was calculated using pesticide residue data, food factor, and correction factor by treatment. TMDI obtained from MRLs and food intake, and food intake was summed as 1,100.99 g, which was 79.1% of total consumption. The percent ratio of TMDI to ADI for 156 pesticides was mostly below 80% and only 30 pesticides exceeded the ADI. In particular, non-treated EDI from pesticide residue data and food intake was summed up to about 43 $\mu\textrm{g}$/day/capita, and the rank was procymidone(8.6 $\mu\textrm{g}$) > maleic hydrazide(8.2 $\mu\textrm{g}$) > EPN(3.7 $\mu\textrm{g}$) > deltamethrin(3.5 $\mu\textrm{g}$) > cypermethrin(3.0 $\mu\textrm{g}$). The treated EDI calculated from pesticide residue data, food intake, and correction factor by culinary treatment was summed up to 13.7 $\mu\textrm{g}$/day/captia. The percentage of ADI was TMDI(79.74%) > non-treated EDI (0.17%) > treated EDI (0.04%), and the exposure level of Korean population to whole pesticides was below the level to produce health risk. Oncogenic risk of five pesticides used in Korea whose oncogenic potency(Q*) was known were assessed from TMDI and treated EDI. Dietary oncogenic risk for Korean was estimated to be 2.0$\times$10-3 on the basis of TMDI, 8.3$\times$10-7 on the basis of treated EDI. The oncogenic risk from TMDI exceeded the risk level(1$\times$10-6) of EPA, whereas the oncogenic risk from treated EDI and real exposure level lower than that of EPA.

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Residue of Organophosphorus Pesticides in the Coastal Environment on the Cheju Island (제주도 연안 해양환경 중 유기린계 농약의 잔류)

  • Kim, Jeong-Ho;O, Yun-Geun;Park, Byeong-Yun
    • Journal of Environmental Science International
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    • v.8 no.4
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    • pp.503-507
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    • 1999
  • To study the residue of organophosphorus pesticides in the ocean environment on the Cheju island, EPN[O-ethyl-O-4-nitrophenyl phenylphosphonothioate] and monocrotophos [Dimethyl-1-methyl-2-methyl carba-moylvinylphosphate] of organophosphorus pesticides are surveyed on coastal environment of Cheju city and Wimi in May and October 1996. The qualified limit detection of EPN and monocrotophos are 0.005ng/mL and 0.006ng/mL in the water by GC-FPD, respectively. The qualified limit detection of EPN and monocrotophos are 0.010ng/g and 0.012ng/g in the solid such as sediment and sea organism by GC-FPD, respectively. EPN and monocrotophos are not detected in seawater and sedimnet. Moreover EPN and monocrotophos are neither detected in seaweed cava (Ecklonia cava), Agar (Gelidium amansii), turban sell(Batillus cornutus) and sea urchin(Anthocidaris Crassispina). EPN, monocrotophos used in the farm on the Cheju island are not residued in the coastal environment in the Cheju island.

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A Study On the Design of Mixed Radix Converter using Partitioned Residues. (분할 잉여수를 사용한 혼합기수변환기 설계에 관한 연구)

  • 김용성
    • The Journal of Information Technology
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    • v.4 no.4
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    • pp.51-63
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    • 2001
  • Residue Number System has carry free operation and parallelism each modulus, So it is used for special purpose processor such as Digital Signal Processing and Neuron Processor. Magnitude comparison and sign detection are in need of Mixed Radix Conversion, and these operations are impediment to improve the operation speed. So in this Paper, MRC(Mixed Radix Converter) is designed using modified partitioned residue to speed up the operation of MRC, so it has progressed maximum twice operation time but increased the size of converter comparison to other converter.

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Soil Quality Assessment for Environmentally Sound Agriculture in the Mountainous Soils - Physical Properties of the Soil and Collection of Sediment Data - (산지에서의 환경보전형 농업을 위한 토양의 질 평가 -토양의 물리적 특성과 유사자료 수집 -)

  • 최중대;김정제;양재의;정진철;윤세영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.4
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    • pp.85-93
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    • 1998
  • In the 2nd year study of a 5 year project to evaluate the soil quality and develop the best management practices for mountaineous soils, 11 runoff plots were treated and monitored with respect to physical property of the soil, runoff and sediment discharge, and the following results were obtained. 1. Bulk density and porosity did not show any siginificant difference between experimental treatments. 2. Runoff was basically dependent on the soil's physical property and tillage. Up-and-down plots showed the highest runoff while contour plots the lowest runoff. 3. Sediment yield in the mountaineous soils was directly related to tillage and residue cover. Residue covered plots showed the lowest sediment yield and up-and-down plots the highest sediment yield. And it is recommended that the best management practices using till_age and residue cover for the mountaineous soils must be developed to protect soil quality and maintain agricultural productivity.

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Effect of Polar Amino Acid Residue Substitution by Site-Directed Mutagenesis in the N-terminal Domain of Pseudomonas sp. Phytase on Enzyme Activity

  • Lee, Ga Hye;Jang, Won Je;Kim, Soyeong;Kim, Yoonha;Kong, In-Soo
    • Journal of Microbiology and Biotechnology
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    • v.30 no.7
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    • pp.1104-1107
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    • 2020
  • The N-terminal domain of the Pseudomonas sp. FB15 phytase increases low-temperature activity and catalytic efficiency. In this study, the 3D structure of the N-terminal domain was predicted and substitutions for the amino acid residues of the region assumed to be the active site were made. The activity of mutants, in which alanine (A) was substituted for the original residue, was investigated at various temperatures and pH values. Significant differences in enzymatic activity were observed only in mutant E263A, suggesting that the amino acid residue at position 263 of the N-terminal domain is important in enzyme activity.

Anti-arteriosclerotic and Anti-hyperlipidemic Effects of Sea Mustard (Undaria pinnatifida) in Sprague-Dawley rats

  • Lee, Seung-Joo;Ha, Wang-Hyun;Choi, Hye-Jin;Cho, Soon-Yeong;Choi, Jong-Won
    • Fisheries and Aquatic Sciences
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    • v.13 no.3
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    • pp.197-205
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    • 2010
  • This study investigated the inhibitory effects of sea mustard on high-fat diet-induced obesity and hyperlipidemia in Sprague-Dawley rats. Sea mustard (Undaria pinnatifida) powder, sea mustard ethanol extract, and sea mustard ethanol-extracted residue were tested. The ethanol extracted residue had the most beneficial anti-hyperlipidemic activity. Alginate in the sea mustard was considered to be the key component. The ethanol-extracted residue of sea mustard also had antioxidant activity, which may be effective in preventing hyperlipidemia by increasing the enzymatic activity of superoxide dismutase, which can remove active oxygen from the bloodstream.

Preparation of Anode Material for Lithium Secondary Battery using Pitch-coated Graphite Residue Compounds

  • Ko, Young-Shin;Oh, Won-Chun
    • Carbon letters
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    • v.8 no.3
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    • pp.207-213
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    • 2007
  • The properties and electrochemical characteristics of anode material using pitch-coated graphite residue compounds by heat-treatment at $600^{\circ}C$ for 1 hour were investigated. The distance of layers of pitch-coated graphite residual compounds was 3.3539 ${\AA}$, which was as same as that of graphite. Its electrochemical and charge discharge characteristics were tested according to different four types of carbon material, natural graphite, pitch-coated graphite, amorphous graphite and pitch-coated graphite residual compounds, respectively. So it was shown the best charge-discharge characteristics in all of the samples. For the electrochemical and charge-discharge characteristics, although pitch-coated graphite residual compounds had different carbon contents 70% and 80%, these two samples were shown good electrochemical and charge-discharge characteristics.

Residue characteristics of hexaconazole and chlorothalonil in several fruits (과일의 형태적 특성에 따른 농약의 잔류성과 분포)

  • Lee, Hee-Dong;Kyung, Kee-Sung;Kwon, Hye-Young;Ihm, Yang-Bin;Kim, Jin-Bae;Park, Seung-Soon;Kim, Jang-Eok
    • The Korean Journal of Pesticide Science
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    • v.8 no.2
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    • pp.107-111
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    • 2004
  • The study was carried out to investigate the pesticide residual characteristics in peaches, pear and grape. Pesticide residue patterns were remarkably different because of major factors affecting the pesticide residue patterns such as ratios of surface to weight, surface matrices, cultivations, sizes, increase rate of weight, and varieties of fruits, etc.. Pesticide residue levels in grape appeared higher than those in peaches and pear, because the pesticide solution sprayed was infiltrated and accumulated between grape granules. The matrices composing of fruit surface and the ratios of surface area to weight on fruits seemed to playa key role for determining the pesticide residual characteristics in fruits.

Residue by elapsed time of non-enzymatic antioxidants in dentifrice (세치제에 함유된 비효소계 항산화제의 경시변화에 따른 잔류량)

  • Park, Jung-Eun;Park, Yong-Duk;Hong, Tae-Gi;Jang, Jong-Hwa
    • Journal of Korean society of Dental Hygiene
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    • v.16 no.5
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    • pp.783-790
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    • 2016
  • Objectives: The purpose of this study is to evaluate the non-enzymatic antioxidants stabilities in dentifrices by ascorbic acid and tocopherol according to the chemical condition. Methods: For the analysis of two antioxidants, HPLC UV detector system was used. HPLC was performed using sodium sulfate, acetonitrile(ACN), methanol(MeOH) and measuring absorbance at 240-295 nm. To confirm general pH reaction of two compounds, buffer solution was prepared for the analysis. The dentifrice was titrated by pH so as to examine the change of elapsed time in dentifrice. Linearity of calibration curve of two antioxidants was measured. Results: Each compound showed good linearity at optimized wavelength as well as showing good precision. General pH reaction of two antioxidants was examined. Ascorbic acid showed the highest residue(63.23%) at pH 10 and the lowest residue(2.77%) at pH 4. Tocopherol showed the highest residue(55.70%) at pH 7 and the lowest residue(3.31%) at pH 4. As a result of changing elapsed time of antioxidants in dentifrice by pH, components were remained stably at low temperature($39.2^{\circ}F$) and pH 7. Conclusions: It is necessary to keep dentifrice including ascorbic acid and tocopherol, and non-enzymatic antioxidants at pH 7 and low temperature for improving chemical stability.