【作者】 陶庆会；

【导师】 岳永德；

【作者基本信息】 安徽农业大学 ， 植物病理学， 2001， 硕士

【摘要】 本实验应用高压汞灯、氙灯和太阳光为实验光源，研究了氟乐灵在硅胶G、石英砂和膨润土表面的光解规律，对氟乐灵发生光稳定化的影响因素和机理作了进一步的探讨；并对吸附态氟乐灵进行了生物活性的比较测定。主要研究结果如下：1．在高压汞灯下，研究了氟乐灵在膨润土、石英砂和硅胶G表面的光解动力学。结果表明，不同的吸附介质对氟乐灵的光稳定性有一定的影响。氟乐灵在玻片、硅胶G、石英砂和膨润土表面的光解半衰期分别为24.78分钟、98.51分钟、106.41分钟和220.42分钟；可见，氟乐灵在膨润土表面的光稳定性得到明显增强。2．一些农药和表面活性剂在分别与氟乐灵混合时，对吸附态的氟乐灵光解产生一定的影响。在太阳光下，当以硅胶G作为吸附介质时，拟除虫菊酯类农药和丁草胺与氟乐灵在剂量比1∶1时，均表现为敏化作用；剂量比为10∶1时，则又都具有光猝灭剂的功能，而1∶5时则部分表现为光猝灭作用，部分表现为光敏化作用。在石英砂表面，丙烯菊酯使TF的光解半衰期延长为单独处理的1.64倍。氰戊菊酯则使TF在膨润土表面光稳定性增强，照光18小时后，单独的TF已降解了27.05％，而在氰戊菊酯与TF共存处理中，TF仅降解了5.41％。8种表面活性剂与氟乐灵共存时对氟乐灵光稳定性的影响研究表明；在硅胶G表面，十二烷基硫酸钠是氟乐灵较强的光敏化剂，而十二烷基苯磺酸钠则具有极显著的光猝灭作用，使氟乐灵的光解半衰期延长为单独处理的35.79倍。几种阳离子表面活性剂均可使TF在膨润土表面的光稳定性增强，尤以氯化十六烷基吡啶（CPC）较为明显，使TF光解半衰期延长了6.27倍。3．几种色素对氟乐灵在硅胶G表面的光稳定化研究表明，在太阳光下，色素结晶紫、核黄素、亚甲基蓝、孔雀石绿对氟乐灵均表现较强的光猝灭效应，以结晶紫的光猝灭效率最大，核黄素次之，分别使氟乐灵的光解半衰期延长为单独处理的14.64倍和4.25倍。在石英砂和膨润土表面，氟乐灵也表现受到上述色素同样的影响。另外，Fe³⁺在硅胶G、石英砂和膨润土中存在时，均会使TF光解速率减慢。4．氟乐灵在膨润土表面光稳定化研究表明，当结晶紫存在时，可显著增强氟乐灵对光的稳定性，明显比氟乐灵单独吸附在膨润土中的效果要好。高压汞灯下照光14小时后，单独氟乐灵光解残存率仅为12．10％；而在膨润土－色素复合体中，当色素浓度为 0．IInM、0．2 InM和 0、4 InM时，氟乐灵光解残存率分别为58．25％、52．14％和48．35％。结果指出，结晶紫对氟乐灵光稳定性的增强效果与其存在浓度成一定的负相关，以浓度为0＊时对氟乐灵光稳定效果最好，由此可以排除结晶紫对氟乐灵的光稳定化作用主要是由于光屏蔽造成的可能性。5．吸附态氟乐灵的生物活性测定结果表明，当氟乐灵以吸附态存在时以汞灯为光源，在 3 50urn波长的光照下照光 9 ，J’时，对其除草活性并没有明显的影响，其最低有效浓度为0．4邯；并且以膨润土－结晶紫复合体为介质时氟乐灵的光稳定性最强，在照光12小时后，光解率为39．59％，而单独的氟乐灵和氟乐灵－膨润土处理的光解率则分别为93．82o、64。0硼。在照光64小时后，单独的氟乐灵基本上不再具有生物活性，而吸附态氟乐灵则仍有较高的生物活性，在含有色素和未含色素的膨润土介质中，生长抑制率分别为66．89O和54．800。更多还原

【Abstract】 High pressure mercury lamp(L-IPML),xenon and sunlight were used as light sources in the present experiment. Photolytic kinetics of trifluralin(TF)on silica gel, quartz sand and bentonite surfaces,and the effects of some combined pesticides, surfactants, dyes and metal ions on photostability of TF on the adsorbents were studied. Then, the photostabilization mechanism and bioactivity of TF in the state of adsorption were further investigated. The main results were summarized as following I .Photolytic kinetics of TF on four kinds of adsorbents were studied under 1-IPMIL .The result manifested that photostability of TF was affected by different solid media surfaces. The half lives of TF adsorbed on glass, silica gel, quartz sand and bentonite were 24.78 minutes,98.51 minutes,106.41 minutes and 220.42 minutes respectively. The photostabilization of TF adsorbed on bentonite was most obvious. 2.Some combined pesticides and surfactants could alter the photolytic rate of TF on silica gel under sunlight When mixed with pyrethroids or butachlor in the ratio of 1: I,the photolytic rate of TF increased. When the dosage ratio of pyrethroids or butachlor and IF was 10: 1,the half-life of TF was put off. But when the ratio was 1 :5,some of them could accelerate the photodecomposition of TF while others retarded the photodegradation of TF. Auethrin could make TF degrade slowly on quartz sand and the half-life of TF co-existing with auethtin was as 1 .64 times as that of IF alone. Besides, fenvalerate could strengthen the photostability of IF adsorbed on bentonite. After 18 hours of irradiation, the photolytic rate of TF alone was 27.05% while the rate of TF combined with fenvalerate was only 5.4 1%.Effects of eight kinds of surfactants on the photolysis of TF was also evaluated. SDS was demonstrated as a photosensitizer, while ABS displayed remarkably photoquenching effect and the half-life of TF in the latter treatment was as 35.79 times as that of TF alone. Some surfactants could increase the photostability of TF adsorbed on bentonite. 111 The effects of CPC on the photostabilization of TF was observed significantly. The half-life of IF was prolonged 6.27 times. 3. Effect of several dyes on the photostabilization of TF on silica gel was also studied. Alt of them could delay the photolysis of IF under sunlight, while the effects of crystal violet and viboflavin were especially obvious and the half lives of IF in these treatments were prolonged as 14.64 times and 4.25 times as that of IF alone respectively. The photodegradation of IF adsorbed on quartz sand and bentonite was also affected by the above dyes. In addition, cationic ion of iron could postpone the photodegradation of IF adsorbed on silica gel, quartz sand and bentonite. 4. While crystal violet (CV) existed, IF adsorbed on bentonite could be photo- stabilized significantly. The remaining of IF alone was only 12.10% after 14 hours of irradiation alone on bentonite under HPMIL. But on B-CV complexes, the remaining of IF were 58.25%, 52.14% and 48.3 5%, corresponding to different equilibrium concentration of CV, that is 0.1mM, 0.2mM and 0.4mM respectively. The result demonstrated that although CV could enchance the photostabilization of IF ,different concentration displayed different effects on the photostability of IF. The better outcome was observed while the equilibrium concentration of CV was 0.1mM. Therefore, explanation about the更多还原