The Residual Dynamics In Soybean And The Behavior Of Photodegradation Of Propisochlor

Propisochlor is a kind of new ex- herbicide of the amide, mainly using for the grain undergraduate course miscellaneous grass and part of broad-leaved and miscellaneous grass that prevents soybean, corn, and paddy rice in the field. The determination degradation of propisochlor in soil and soybean plant and light degradation were studied by gas chromatography for the establishment of the MRL standard.The samples were all extracted with methanol and distilled water, using petroleum to extract. The soybean plant samples were cleaned-up with silica gel and activated carbon pillar at a proper proportion. Firstly petroleum was used to wash the pillar, then we used the mixed liquor petroleum: ethyl acetate (2:3 V/V) to wash the pillar again, in order to eliminate impurity and pigment. The HP 6890 was equipped with μ-ECD detector. Capillary column is HP5 30.0m×320μm×0.25μm. Carrier gas is N₂. The speed of the carrier gas was 1.0ml/min. The column temperature was programmed.The different addition level of soil, soybean plant and soybean was 0.01mg/kg, 0.10mg/kg, 1.00mg/kg, the recovery rate of propisochlor was separately 81.3%～96.7%, 81.2%～92.5%, 82.2%～92.1%, and C.V. was 1.60%～3.07%. The recovery was all exceed 80% and measured up to residual analysis. The LOD(limit of detection) of this method was 7.4×10^-12g, and the LOQ(limit of quantification) for soil, soybean plant and soybean was 0.002mg/kg.The degradation of propisochlor in soil and soybean plant was studied by GC method through the 2-yr-2-field experiments in Jilin province and Heilongjiang Province. The experiment in Jilin province: in soil, the dynamic equation in 2004 was C=0.9280e^-0.030t and the half-life was 23.10d, and the dynamic equation in 2005 was C=0.8191e^-0.0315t andhalf-life was 22.00d. In soybean plant, the dynamic equation in 2004 was C=4.6721e^-0.2251t and the half-life was3.08d, and the dynamic equation in 2005 was C =7.6504e^-0.1462t and half-life was 4.74d. The experiment in Heilongjiang province: in soil, the dynamic equation in 2004 was C=0.8674e^-0.0299t,and half-life was 23.18d; and the dynamic equation in 2005 was C=0.8798e^-0.027t, the half-life was 25.67d. 2-yr-2-field experiment showed that...