Gas chromatographic determination of residue levels of the herbicides trifluralin, benefin, ethalfluralin, and isopropalin in soil with confirmation by mass selective detection |
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Authors: | S D West J H Weston E W Day |
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Institution: | Division of Eli Lilly and Co., Greenfield, IN 46140. |
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Abstract: | A method is presented for the simultaneous or individual determination of the dinitroaniline herbicides trifluralin, benefin, ethalfluralin, and isopropalin in soil. The herbicides are extracted with acetonitrile-water (99 + 1), and the extracts are purified with small, disposable Florisil cartridges prior to analysis by gas chromatography using an electron capture detector or a mass selective detector. When electron capture detection is used as the primary detection system, confirmation with selective detection can be obtained using gas chromatography-mass spectrometry with a mass selective detector and a capillary column operated in the split mode. The limit of detection is 0.01 ppm, and recoveries averaged 95-112% for the 4 herbicides in several different soil types fortified at levels of 0.01-0.33 ppm. |
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