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Hong, Kyung-Sik;Choi, Gyung-Ja;Kim, Heung-Tae;Hwang, In-Taek;Cho, Kwang-Yun;Kim, Jin-Cheol
- The Korean Journal of Pesticide Science
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- v.6 no.3
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- pp.202-208
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- 2002
A phytotoxin was purified by repeated chromatography from liquid cultures of Fusarium oxysporum BG isolated from barnyardgrass. Its chemical structure was determined to be dehydrofusaric acid by mass and NMR spectral analyses. The substance showed a potent phytotoxic activity against growth of duckweed with a $EC_{50}$ value of $1.5{\mu}g/ml$. It also inhibited the root growth of barnyard millet, cress, barnyard grass, and rice cultivar 'Dongjin'. However, it had no inhibitory activity against seed germination of barnyard millet and cress, and the shoot growth of the four plant species.
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Lee, Jeong-Min;Jang, Gi-Chul;Hwang, Keon-Joong
- Journal of the Korean Society of Tobacco Science
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- v.29 no.2
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- pp.132-139
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- 2007
This study was performed to apply the more rapid and accurate sample preparation, and the high selectivity and sensitivity of the analyte detection by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). QuEChERS (quick, easy, cheap, effective, rugged and safe) method was validated for 49 agrochemicals in the CORESTA Agrochemical Advisory Committee guide and amenable to GC-MS/MS determination. In QuEChERS method, the effects of sorbents (PSA, $C_{18}$ and GCB) and matrix of the analytes in tobacco types (flue-cured, burley and oriental) were investigated. MS/MS acquisition provided high specificity and selectivity for agrochemicals and low limit of quantification. QuEChERS by using PSA alone and the matrix-matched standards gave good recoveries and RSD values in three types of tobaccos. QuEChERS method was no needed to be complex clean-up procedure and would be used as the fast and easy method for agrochemical residue analysis in tobacco.
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