• Title, Summary, Keyword: 산성제초제

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Inter-lab validation for the derivatization method by TFE/TFAA of acidic herbicides (산성 제초제류의 TFE/TFAA 유도체화 방법에 대한 실험실간 정도관리)

  • Pyo, Hee-Soo;Park, Song-Ja;Lee, Kang-Jin;Hong, Jong-Ki;Shin, Ho-Sang
    • The Korean Journal of Pesticide Science
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    • v.9 no.2
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    • pp.159-165
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    • 2005
  • A sensitive derivatization method by using the TFE/TFAA as derivative reagent is proposed for the determination of acidic herbicides in water, by using this method, method detection limits are improved by 10 times and sample volumes are decreased by 5 times compared with other methods such as U.S. EPA and SPEED 98. And also, in order to suggest higher creditable standard operating procedure (SOP), intra- and inter-lab validation test carried out by four laboratories include our lab. The results of intra and inter-lab validations in same experimental conditions show good linearity in given range of concentrations as a $0.1{\sim}10.0$ ng/ml, and range of accuracies and precisions show $-20.5{\sim}12.2$ bias%, $0.55{\sim}24.48%$ (for intra-lab validation) and $-6.66{\sim}0.80 bias%$, $1.92{\sim}13.86%$ (for inter-lab validation), respectively.

Understand the Molecular Orbital Theory on the Hydrolytic Reactivity of Herbicide Flumioxazine (제초제 Flumioxazine의 가수분해 반응성에 관한 분자 궤도론적 이해)

  • Sung, Nack-Do;Jung, Hoon-Sung
    • The Korean Journal of Pesticide Science
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    • v.8 no.4
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    • pp.265-271
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    • 2004
  • Hydrolytic reactivities of N-phenylphthalimid herbicide flumioxazine (S) were disccused using molecular orbital (MO) theoretical method. It is revealed that below pH 5.0, the protonation $(SH^+)$ to carbonyl oxygens atom $(O_{21})$ of 1,2-dicarboximino group by general acid catalysis $(k_A)$ with hydronium ion $(H_3O^+)$ proceeds via charge controled reaction. Whereas, the specific base catalysis $(k_{OH})$ with hydroxide anion via orbital controled reaction occurs above pH 8.0. We may concluded that in the range of pH $5.0\sim8.0$, the hydrolysis proceeds through nucleophilic addition elimination $(Ad_{N-E})$ reaction, these two reactions occur competitively.

Determination of 2, 4-D and 2, 4, 5-T in River Water and Drinking Water by Gas Chromatograph/Mass Spectrometer (GC/MS를 이용한 수질시료 중 2, 4-D와 2, 4, 5-T의 분석에 관한 연구)

  • 표희수;신혜승;박송자
    • Environmental health and toxicology
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    • v.15 no.3
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    • pp.107-113
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    • 2000
  • Chlorophenoxy acids are one of the most useful classes of chlorinated herbicides. Specially 2, 4-D and 2, 4, 5-T were known to endocrine distruptors. In this study, these pesticides in water samples were extracted by liquid-liquid extration at acidic conditions and then derivatization of acidic group was carried out various esterifications using by CH$_3$I/Acetone -K$_2$CO$_3$, H$_2$SO$_4$/MeOH or TFAA/TFE. That result, Sensitivities of TFE derivatized 2, 4-D and 2, 4, 5-T are prior to the others. The recoveries of 2, 4-D and 2, 4, 5-T were 98% and 82% respectively using diethyl ether as an extracting solvent.

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Allelopathic Activity and Determination of Allelochemicals from Sunflower (Helianthus annuus L.) Root Exudates II. Elucidation of Allelochemicals from Sunflower Root Exudates (해바라기(Helianthus annuus L.) 근분비물질(根分泌物質)의 타감작용(他感作用) 및 타감물질(他感物質)의 동정(同定) II. 타감성(他感性) 해바라기 근분비물질(根分泌物質)의 동정(同定))

  • Park, K.H.;Moody, K.;Kim, S.C.;Kim, K.U.
    • Korean Journal of Weed Science
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    • v.12 no.2
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    • pp.173-182
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    • 1992
  • Regardless of the test species, germination was adversely affected by the different concentrations of the acidic and neutral fractions of sunflower root exudates while the basic and aqueous fractions had no effect on germination. In both test species, root lengths were inhibited slightly more than shoot lengths. Significant reduction in fresh weights of the test species was observed when the test species were treated with the acidic and neutral fractions but not with the basic and aqueous fractions. Six compounds, hydroquinone, ${\beta}$-resorcyclic acid, vanillic acid, caffeic acid, salicylic acid, and quercetin, were characterized from the acidic fraction. Seven compounds, hydroquinone, gentisic acid, ${\beta}$-resorcyclic acid, vanillic acid, caffeic acid, ferulic acid, and quercetin, were elucidated from the neutral fraction.

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Distribution and Mobility of Herbicide $^{14}C$-Molinate in a Rice-Paddy-Soil Lysimeter (벼 재배 Lysimeter 환경에서 제초제 $^{14}C$-molinate의 분포 및 이동성 평가)

  • Park, Byung-Jun;Kim, Chan-Sub;Park, Kyung-Hun;Park, Hyeon-Ju;Im, Geon-Jae;Choi, Ju-Hyeon;Shim, Jae-Han;Ryu, Gab-Hee
    • The Korean Journal of Pesticide Science
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    • v.10 no.3
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    • pp.172-182
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    • 2006
  • This study was designed to assess molinate fate in the lysimeter by measuring the total radioactivity in the leachate, evolved $^{14}CO_2$, and $^{14}C$-residues in soil and rice plant. The amounts of applied $^{14}C$ in the leachate from the lysimeter for 20 weeks were 1.05% in 2.31 pore volume (217,465 mL) at the first and 0.34% in the second year, respectively. The amount of $^{14}CO_2$ evolved from the lysimeter accounted for 6.47% and 0.03% of applied $^{14}C$ in the first and second year. The $^{14}C$-activities in the soil layer of the lysimeter were distributed 18.0% (1st) and 13.3%(2nd) in the depth of 0 to 10 cm, 4.3 (1st) and 1.1% (2nd) in the depth of 10 to 20 cm. Most of the applied $^{14}C$ was detected in the top 20 cm soil layer. Total $^{14}C$ in rice plants grown at lysimeter were detected 11.46% of applied $^{14}C$. 11.11% in straw, 0.24% in brown rice grain, 0.08% in chaff and 0.03% in ears were distributed in the first year. Consequently, environmental fate of molinate using lysimeter simulating a paddy rice field were investigated 25.24% in soil, 11.64% in rice plant, 1.05% in leachate, 6.74% in evolved $^{14}CO_2$ and 0.02% in volatilized organic chemicals in the first year.