Study On The Residual Dynamics Of Triadimenol In Rice And Safety Evaluation

In order to provide basis for residual rule of 15% triadimenol WP, analysis methods of 15% triadimenol residue and degradation in soil,rice and water and its final residues were studied. The results were shown as follows:1. Residue analysis method of triadimenol was established in rice,water and soil. The triadimenol could be extracted with acetone, and then re-extracted with dichloromethane. After being concentrated by evaporation, the extracts were detected in NPD of high sensitivity. The accuracy, reappearance and precision of the method well satisfied the essential rules of pesticide residue determination.2. Degradation dynamic of 15% triadimenol in rice was studied by a two-year field experiment in Tianjin and Anhui province. The rice was treated with pesticide at 140 gai mu-1. Samples of soil ,water, stalk, hull and rice were analysised at different time, then the degradation procedure was corresponding to the mathematic pattern: C=C0e-kt. The result showed that 15% triadimenol was degraded easily in soil and potatoes.3. With sprayed 15% triadimenol on rice two or three times at recommended dosage (70gai mu-1), at the interval of 35d, the results were as follows: at two times, the final residue of triadimenol was 0.0137~0.0228mg·kg-1in stalk, ND in soil, ND~0.0318mg·kg-1in hull and ND~0.0211mg·kg-1in rice. At three times, the final residue of triadimenol was 0.015~0.0327mg·kg-1in stalk, ND in soil, 0.0224 ~0.0364mg·kg-1in hull and ND~0.0628mg·kg-1in rice. With sprayed 15% triadimenol on rice two or three times at 140gai mu-1, at the interval of 35d, the results were as follows: at two times, the final residue of triadimenol was 0.0367 ~0.0615mg·kg-1in stalk, ND in soil, ND~0.0718mg·kg-1in hull and ND~ 0.0863mg·kg-1 in rice. At three times, the final residue of triadimenol was 0.0367~0.0865mg·kg-1in stalk, ND in soil, 0.0658~0.0932mg·kg-1in hull and 0.0402~0.0944mg·kg-1in rice. The result showed that it was safe to use 15% triadimenol at this recommended dosage, at two or three times, 35d interval by safety assessment.4. We report in detailed the synthesis and characterization of molecular sieve. In particular, we have examined the influence of the synthesis times and (CTMA)Br. Results of experiments indicated that the photocatalytical reaction of molecular sieve coated with TiO2 is mainly the result of TiO2. The synthesis of a new mesoporous silica molecular sieve promoted the catalytical effect.