霜霉威在辣椒中的消解动态和残留规律及土壤中的光解研究

发布时间：2018-05-30 05:15

本文选题：辣椒 + 霜霉威　；参考：《湖南农业大学》2015年硕士论文

【摘要】：本文研究了辣椒及土壤样品中霜霉威残留量的检测方法；我国自然环境下霜霉威在辣椒和土壤中的消解动态和残留规律；土壤中霜霉威的光化学降解,为霜霉威的合理使用、生态环境安全性评价以及土壤环境修复提供科学依据。主要研究结果如下：(1)建立了适用于我国实验室条件的检测辣椒(鲜辣椒、干辣椒)和土壤中霜霉威残留量的GC-NPD方法。方法的平均添加回收率为84.1%-106.8%,变异系数在0.8%-4.8%之间；鲜辣椒、土壤和干辣椒中霜霉威最低检测浓度分别为0.05 0.05 mg/kg和0.10mg/kg。该检测方法可用于我国农业、食品和环境监测部门对辣椒和土壤样品中霜霉威残留量的检测。(2)湖南、广东和浙江三地模拟试验研究了辣椒和土壤中霜霉威的消解动态,霜霉威在辣椒和土壤中的消解均符合一级化学反应动力学方程：Ct=Coe-kt,消解半衰期分别为4.01-8.92d和5.08-7.66d。试验结果表明：霜霉威在辣椒和土壤中消解较快,属较易降解的农药。(3)在三个省的自然条件下,按照推荐的施药量和施药方法在辣椒上施用66.5%霜霉威盐酸盐水剂,最后一次施药后7d以上收获的辣椒中霜霉威的残留最大值为0.870mg/kg,低于我国制定霜霉威在辣椒中的最大允许残留限量(MRL) 3.0mg/kg。根据试验结果,建议66.5%霜霉威盐酸盐水剂在辣椒上合理使用技术标准为：辣椒生长期,用66.5%霜霉威盐酸盐水剂1650 ml/ha (有效成分1191.3g/ha)防治辣椒疫病,兑水750L/ha稀释后茎叶喷雾,最多施药3次(施药间隔期为7-10天),安全间隔期为7天。(4)霜霉威在土壤中的光降解符合化学反应一级动力学方程。高压汞灯照射下土壤中霜霉威的光解速率明显大于太阳光照射下的光解速率,半衰期分别为121.6h和203.8h；调节土壤pH值对霜霉威的光解有较大的影响,pH=10时半衰期比pH=7时缩短了67.2%；添加0-200mg/kg TiO2时,土壤中霜霉威的光解速率随着Ti02浓度的增加而逐渐增大；加入一定量的Fe3+对增强Ti02的光催化作用效果显著,不同Fe3+/TiO2配比条件下土壤中霜霉威的光解速率表现为：10：20020：2005：2000：200,半衰期分别为33.6h、50.2h、55.0h和72.9h。
[Abstract]:In this paper, the method for the determination of fenustrin residues in capsicum and soil samples, the digestion dynamics and residues of frostbitarb in pepper and soil in natural environment of China, the photochemical degradation of frostbitarb in soil, and the reasonable use of frostbitarb were studied in this paper. Ecological environment safety evaluation and soil environmental restoration provide scientific basis. The main results are as follows: (1) A GC-NPD method was established for the determination of fenustrin residues in pepper (fresh pepper, dry pepper) and soil under laboratory conditions in China. The average recovery was 84.1% -106.8%, the coefficient of variation was between 0.8% and 4.8%, and the lowest detection concentration of fenustrin in fresh pepper, soil and dry pepper was 0.05 mg/kg and 0.10 mg / kg, respectively. This method can be used for the determination of fenustrin residues in capsicum and soil samples by agricultural, food and environmental monitoring departments in China. The dynamics of the dissolution of fenustrin in capsicum and soil were studied by simulation tests in Hunan, Guangdong and Zhejiang provinces. The digestion of creamethanil in capsicum and soil was in accordance with the first-order chemical reaction kinetics equation: Ctchon Coe-kt, and the digestion half-life was 4.01-8.92d and 5.08-7.66d, respectively. The results showed that the chloramarb was a relatively fast degradable pesticide in pepper and soil. Under the natural conditions of three provinces, 66.5% of the hydrochloric acid water agent was applied to the pepper according to the recommended application amount and method. The maximum residual value of fenustrin in pepper harvested more than 7 days after the last application was 0.870 mg / kg, which was lower than the maximum allowable residue limit (MRL) of 3. 0 mg / kg. According to the results of the experiment, it is suggested that the technical standard for the rational use of 66.5% hydrochloric acid water agent on capsicum is as follows: during the growth period of pepper, 1650 ml/ha (effective ingredient 1191.3 g / ha) was used to prevent and cure pepper blight, and 750L/ha diluted with water was used to spray the stems and leaves. The photodegradation of creametharb in soil was in accordance with the first-order kinetics equation of chemical reaction at the maximum of 3 times (the interval was 7-10 days and the safe interval was 7 days. 4) the photodegradation of creametharb in soil was in accordance with the first-order kinetics equation of chemical reaction. Under high pressure mercury lamp irradiation, the photolysis rate of sulfamethanil in soil was significantly higher than that under solar irradiation. The half-life was 121.6 h and 203.8 h, respectively. Adjusting the soil pH value had a great effect on the photolysis of fenustrin. The half-life at pH = 10:00 was 67.2% shorter than that at pH = 7, and the photolysis rate increased with the increase of Ti02 concentration when 0-200mg/kg TiO2 was added to the soil. The photocatalytic effect of adding a certain amount of Fe3 on the enhancement of Ti02 was remarkable. Under different Fe3 / TIO _ 2 ratios, the photolysis rate was 10: 20: 2005: 2000: 200, and the half-life was 33.6 hu 50.2 h and 72.9 h, respectively.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X592

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