摘要
为了对二氧化硅载药体系进行评价,以吡唑醚菌酯为模式农药,利用其与正硅酸乙酯在碱性条件下的水解缩合反应,以十六烷基三甲基溴化铵（CTAB）为模板剂,制备了吡唑醚菌酯/二氧化硅微球。通过扫描电子显微镜、Nicolet iS5傅里叶变换红外光谱及高效液相色谱等表征了微球的表面形态和化学结构,测定了其在水中的光解速率;并采用透析袋法探讨了该微球在不同pH值和不同温度下的缓释行为,通过菌丝生长速率法测定了该微球对稻瘟病菌的毒力,评价了其生物活性。结果表明：所制备的吡唑醚菌酯/二氧化硅微球外观形貌较为规整,粒径在0.998～1.428μm之间,其最大载药量可达50.73%。该微球在碱性条件下的释药速率快于酸性条件下,且其释放均符合一级反应动力学方程,在中性条件下其释药符合Ritger-Peppas方程;与pH值相比,温度对其释药速率的影响较小。给药后第5天,所制备吡唑醚菌酯/二氧化硅微球的毒力与原药相近,给药后第9天,其毒力是原药的11.7倍,缓释效果显著。该吡唑醚菌酯/二氧化硅微球在紫外灯照射10 h后光解率为38.98%,明显低于吡唑醚菌酯原药的光解率（68.92%）。
In order to evaluate the silica drug-loading system, the pyraclostrobin/silica microsphere was prepared by the hydrolysis and polycondensation of tetraethyl orthosilicate under alkaline conditions with pyraclostrobin as the pattern pesticide. The surface morphology and the chemical structure of the microsphere were characterized by scanning electron microscope（SEM）, Nicolet iS5 Fourier transform infrared spectrometer（FTIR） and high performance liquid chromatography（HPLC）. And its photodegradation rate in water was also determined.The release behavior under different p H/temperature was studied by dialysis bag method. And the growth rate method was employed to study the virulence against Pyricularia oryzae. The results showed that the pyraclostrobin/silica microsphere exhibited regular appearance with the maximum drug loading of 50.73% and the average particle size of 0.998-1.428 μm. Release property was tested under different p H. The results indicated that the release rate of microspheres under alkaline conditions was greater than that of acidic conditions.In addition, the release rates under both acidic and basic conditions were consistent with the first order kinetics equation. And the release in accordance with the Ritger-Peppas equation in the neutral condition. Compared with p H, temperature had little effect on the release rate. The effect of pyraclostrobin/silica microspheres on the fifth day after administration was similar to that of the technical concentrate, while the virulence on the ninth day after administration was 11.7 times higher than that of the technical concentrate, which indicated that the sustained-release effect of pyraclostrobin/silica microspheres was significant. The photodegradation rate of microsphere was 38.98% after 10 hours exposure to ultraviolet light, which is lower than the technical concentrate（68.92%）.
作者
王娅
王昱翔
张盈
张星
陈伟
李晓刚
WANG Ya1,2,WANG Yuxiang1,2,ZHANG Ying1,2,ZHANG Xing1,2,CHEN Wei1,2,LI Xiaogang1,2(College of Plant Protection, Hunan Agricultural University, Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Changsha 410128, China;)
出处
《农药学学报》
CAS
CSCD
北大核心
2018年第4期506-513,共8页
Chinese Journal of Pesticide Science
基金
化学肥料和农药减施增效综合技术研发专项(2016YFD0201200)
湖南省高校重点实验室平台开放基金(15K064)
关键词
吡唑醚菌酯
二氧化硅
微球
释放动力学
控释
缓释
稻瘟病菌
生物活性
pyraclostrobin
silica
microsphere
release kinetics
controlled-release
sustained-release
Pyricularia oryzae
bioactivity
