5%定虫隆与4.5%高效氯氰菊酯乳油混剂对小菜蛾的室内毒力测定

采用浸叶法在室内条件下测定5％定虫隆、4．5％高效氯氰菊酯单剂以及不同配比混剂对小菜蛾幼虫的毒力。室内毒力测定结果表明，5％定虫隆与4．5％高效氯氰菊酯4种混剂对小菜蛾均有显著的增效作用，其中混配2的增效作用最显著，其共毒系数最高为367．22。     

甲维盐高效氯氰菊酯水分散细粒剂的制备及质量评价

[目的]制备甲维盐高效氯氰菊酯水分散细粒剂,并优化其制备工艺。[方法]以泊洛沙姆188为黏合剂,采用熔融法制备了甲维盐高效氯氰菊酯水分散细粒剂,并以悬浮率为评价指标,通过正交试验设计对制备工艺进行优化。[结果]熔融法制备甲维盐高效氯氰菊酯水分散细粒剂的最佳制备工艺为甲维盐与高效氯氰菊酯比例为1∶9,泊洛沙姆188的用量为20%,十二烷基硫酸钠的用量为1%,泊洛沙姆的活化温度为80℃。[结论]甲维盐高效氯氰菊酯细粒剂的制备工艺可行,制剂悬浮率为98.74%,符合农药制剂的质量标准。     

吡虫啉与氯氰菊酯混配的联合毒力及田间药效

测定了吡虫啉与氯氰菊酯混配对蚕豆蚜和菜青虫的联合毒力,并对两药的混剂进行了防治菜蚜和菜青虫的盆栽和田间药效试验。结果表明,吡虫啉与氯氰菊酯按一定比例混配,对蚕豆蚜和菜青虫的联合作用分别为增效和相加,共毒系数分别为252和112;混剂5%吡·氯乳油18.75~37.5g a.i./hm2盆栽和田间防治十字花科蔬菜蚜虫效果与5%吡虫啉乳油15g a.i./hm2相当,田间对菜青虫的防治效果与10%氯氰菊酯乳油30g a.i./hm2相当,杀虫谱比单剂更广,有利于省工省本保护环境。     

拟除虫菊酯的复配制剂和增效剂

近年来,国内外对农药复配日趋重视。1978年美国农药混剂占农药总产量的50%,日本占40%,1976年印度商品化的混配杀虫剂达90种。农药复配的作用在于延缓抗性、延长残效、兼治、增效、降低成本。显然拟除虫菊酯杀虫剂(以下简称Py)具有高效、广谱、安全、对环境无害等优点,是国际上正在异军突起的一类新型仿生农药,但它也存在内吸性差、杀螨活性低、对鱼毒性大、成本较高等不足之处,而Py与其他类型农药及增效剂复配使用     

防治番茄青枯病复配剂筛选

采用“农药-菌悬液混合”杀菌法．测定了农用链霉素等4种单剂对番茄青枯病菌(Burkhokderia solanacearum)的室内毒力测定，求出各单剂的EC50，并根据“按比例混合法”^[4]复配，结果表明：复配剂I、Ⅱ、Ⅲ都有增效作用，其中以复配剂I的增效作用最明显，最高杀菌率达97．4％(农用链霉素与水合霉素以1：4混配所得制剂)；其次是复配剂Ⅱ，最高杀菌率为91．5％(农用链霉素与立枯净以4：1混配所得制剂)；复配剂Ⅲ的增效作用最低，最高杀菌率为79．3％。     

6%高效氯氰菊酯·氯菊酯水乳剂的高效液相色谱分析

采用高效液相色谱法,使用正相硅胶柱和可变波长紫外检测器,以石油醚-乙酸乙酯混合溶剂为流动相,用外标法对6%高效氯氰菊酯·氯菊酯混配制剂中的有效成分进行同柱定量分析.方法的标准偏差分别为0.038、0.020,变异系数分别为1.35%、1.22%,平均回收率均为99.0%.     

阿维菌素与高效氯氰菊酯对美洲斑潜蝇毒力最佳配比的筛选

采用浸叶法测定了阿维菌素与高效氯氰菊酯混配对美洲斑潜蝇1～2龄幼虫的增效作用及两种药剂混配的最佳配比。结果表明,当二种药剂之比位于0.1440﹕3.0000和0.1800﹕0.0000之间时,混配制剂表现较明显的增效作用;而当二种药剂之比为0.1512﹕2.4000时,增效作用最强,此时的共毒系数最高为163.38。     

苹果果实各部位农药残留量的试验分析

用正己烷:丙酮=l:1(V/V)作提取剂,采用石英毛细管柱,电子捕获检测器,气相色谱法测定苹果果皮、果肉、果核中甲氰菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯农药残留量。对苹果果肉试验结果表明,甲氰菊酯的回收率为80.9%~103.6%,RSD为1.30%~5.18%;氯氰菊酯的回收率为86.1%~103.9%,RSD为1.32%~5.01%;氰戊菊酯的回收率为81.3%~102.9%.RSD为2.09%~5.30%;溴氰菊酯的回收率为80.1%~103.8%,RSD为2.43%~6.39%。试验结果表明苹果果皮、果肉、果核中农药残留量相差较大。     

申嗪霉素和咪鲜胺混配对小麦赤霉病的协同杀菌作用

[目的]评估1%申嗪霉素悬浮剂与40%咪鲜胺水乳剂混配对小麦赤霉病菌的增效作用,并进行田间防治试验。[方法]以1%申嗪霉素悬浮剂和40%咪鲜胺水乳剂的单剂对小麦赤霉病菌EC50为基础剂量,分别按照7∶1、5∶1、3∶1、1∶1、1∶3、1∶5、1∶7比例进行混配,采用共毒系数法验证其增效作用,并通过田间试验验证其增效作用。[结果]申嗪霉素与咪鲜胺在7∶1～1∶5范围内混配,有明显的增效作用,当混配比例为5∶1时,共毒系数CTC最大为262.28。将2种制剂进行桶混,按照每hm2使用1%申嗪霉素悬浮剂820 g与40%咪鲜胺水乳剂55 g桶混,对水675 L喷雾处理14 d后,对小麦赤霉病,的防效为84.65%,显著高于单剂防效。[结论]申嗪霉素与咪鲜胺2种制剂混配应用于防治小麦赤霉病,具有明显的增效作用。     

除虫菊素烟雾剂的加工及其活性测定

研制了除虫菊素和2种拟除虫菊酯类农药的烟雾剂,并测定了所配制的炯雾剂对家蝇的击倒活性.结果表明:当助剂中燃料(细木粉和活性炭)和氧化剂(氯酸钾)的质量比为3∶1∶1时,配制的烟雾剂燃烧稳定无明火.活性测定结果表明:0.13%除虫菊素烟雾剂在1.2、2.5 mg a.i./m3时,对家蝇10 min的击倒率分别为63.3%和67.7%,表现出了一定的活性,而其与联苯菊酯、高效氯氰菊酯按1∶2的比例混配后未表现出明显的增效作用.     

商品化酶抑制-比色法农残速测试剂盒对农药的敏感性测定

探讨商品化的酶抑制-比色法农残速测试剂盒对50种农药的敏感性测定.使用商品化的酶抑制.比色法试剂盒对嘧啶磷等40种有机磷和10种氨基甲酸酯类农药残留进行5个浓度水平的测定;对有3个浓度水平的抑制率大于0的农药,用抑制率和农药浓度的常用对数进行线性拟合,得出相关系数和抑制率方程,并据此计算IC10和IC50,通过IC10...     

有机磷农药对乙酰胆碱酯酶活性的联合抑制作用

为研究二元有机磷农药对乙酰胆碱酯酶活性的影响，分别测定了21种有机磷农药对乙酰胆碱酯酶的半抑制浓度IC50在此基础上用等毒法测定了二元有机磷农药对乙酰胆碱酯酶的缺合抑制作用。结果表明有机磷农药对乙酰胆碱酯酶的联合抑制作用主要表现为协同作用与相加作用，拮抗作用较少发生。量子化学参数分析表明具有相似电子效应的二元混合有机磷农药对乙酰胆碱酯酶的抑制主要表现为协同作用，而电子效应相差较大的二元混合有机磷农药对乙酰胆碱酯酶的抑制主要表现为拮抗作用。     

有机磷农药多残留检测方法的研究进展

建立高效快速的有机磷农药多残留检测方法是近年农药残留检测的一个热点.在多残留检测领域,仪器分析法和酶抑制法发挥着越来越重要的作用,而免疫分析法、生物传感器分析法成为新兴的检测方法.综述了上述有机磷农药多残留检测方法的研究进展,并对发展方向进行了展望.     

钉螺乙酰胆碱酯酶的动力学特性及对氯硝柳胺的敏感性

使用钉螺软体的60%盐析乙酰胆碱酯酶(ACHE)酶液,采用L25(56)正交设计和极(方)差分析法,确定其活性测定的最佳条件组合.改进Ellman法测定氯硝柳胺(Nic)对AChE活性的影响.结果表明:设定的底物浓度等5个因素对钉螺AChE活力影响均达到极显著水平(P≤0.01),其最大活性测定条件组合为酶液0.4 mg/L、碘化硫代乙酰胆碱(底物)6.0 mmol/L、反应体系pH值8.0、反应温度35℃及反应时间5 min,其中底物对AChE活性测定影响最大.Nic影响AChE活性作用且其量效关系明显,8 mg/L的Nic抑制AChE活性为21.03%,说明钉螺AChE对Nic敏感性较差,即认为AChE不是Nic致死钉螺的关键靶标.     

Extraction and Enrichment of Pesticides for Analysis using Binary Supercritical Fluid Mixtures

Abstract

To improve the extraction selectivity in analytical supercritical fluid extraction (SFE), binary mixtures of supercritical fluids have been used to selectively produce lipid‐free extracts of trace pesticide residues for chromatographic analysis. Mixtures of nitrogen and HC‐134a have been used in conjunction with carbon dioxide to selectively extract both fortified and incurred residues from a variety of fatty foods using both experimental and commercially‐available extraction instrumentation. Extraction of fortified pesticides in butter fat showed high recoveries for both organo‐chlorine and ‐phosphorus pesticides with recoveries declining for specific pesticide moieties at the 1 ppb spiking level for CO₂/N₂ mixtures. For CO₂ and HC‐134a mixtures, there was poor and little improvement in analyte recovery relative to using neat SC‐CO₂ for fortified organochlorine pesticides in butter fat at the 0.5–5.0 ppm level. However using a CO₂/HC‐134a mixture for organophosphorus pesticides in butter fat improved recoveries (>90%) of the analytes at the 1–3.5 ppm level relative to using neat SC‐CO₂. Excellent recoveries were obtained for incurred organochlorine and ‐phosphorus pesticides from a variety of food products at ppb levels using either CO₂/N₂ or CO₂/HC‐134 mixtures. Results from these and additional experiments suggest that binary fluid mixtures can significantly reduce the need for additional sample cleanup prior to chromatographic analysis, allowing in some cases, direct injection of the extract after dilution into the gas chromatograph.     

Two types of organophosphate pesticides and their combined effects on heterotrophic growth rates in activated sludge process

BACKGROUND: Pesticides are sometimes non‐biodegradable and, moreover, toxic to microorganisms. If pesticides exceed the tolerance of microorganisms, failure of the activated sludge process (ASP) occurs. Therefore the effects of two types of organophosphate pesticides on heterotrophic growth rate constant in sludge from ASP were investigated. Oxygen uptake rate was employed to measure the rate constants. RESULTS: The results indicated that the value of heterotrophic growth rate constant decreased from 3.88 d^?1 to 1.46 d^?1 or by 62% when 0.5 mg L^?1 of glyphosate was added. When adding 0.5 mg L^?1 of malathion, the value of heterotrophic growth rate constant decreased to 1.33 d^?1 or by 66%. The value of heterotrophic growth rate constant decreased to 1.98 d^?1 or by 49% when 0.5 mg L^?1 of pesticide combination (50% for each) was added. CONCLUSIONS: The inhibitory effects of glyphosate and malathion were in good agreement with non‐competitive inhibition kinetics, but pesticide combination did not follow non‐competitive kinetics. The inhibition coefficient values for glyphosate, malathion and their combination were 0.29, 0.29 and 0.58 mg L^?1, respectively. For comparison, linear and exponential types of models were derived by regression. According to non‐competitive kinetics, and linear and exponential models, the inhibitory effects of glyphosate and malathion were almost consistent. Finally, the degree of inhibition was simulated using different types of model. It was found that the toxicity of the two pesticides agreed with the antagonism well. Copyright © 2009 Society of Chemical Industry     

靶标酶在农药研发中的作用

靶标酶在农药研发中具有极其重要的作用,大多数新开发的超高活性农药的靶标都是各种重要的代谢酶系统,了解靶标酶的作用机理,将有助于开发新型高效、低毒、专一性好的农药.综述了除草剂和杀虫剂作用于靶标酶的机理、针对专一靶标酶开发的除草剂和杀虫剂品种、昆虫和杂草产生抗药性的机制,并对新型除草剂和杀虫剂的开发前景进行了展望.     

Reversible acetonitrile-induced inactivation/activation of thermolysin

Thermolysin is catalytically inactive in mixtures of 10-15 % acetonitrile in aqueous buffer. Unexpectedly, dilution of the inactive enzyme with acetonitrile leads to complete recovery of the catalytic activity in a similar way to dilution with aqueous buffer. Circular dichroism and fluorescence studies of thermolysin in the same solvent mixtures reveal discontinuous changes in the overall secondary and tertiary protein structure that correlate well with the reversible differences in catalytic activity. The spectra on either side of the minimum activity point are different from each other, a fact indicating that the enzyme may be able to access two active conformations which are thermodynamically stable in different solvent environments.     

Application of a microassay method to study enzymatic hydrolysis of pretreated wheat straw

BACKGROUND: The conversion of lignocellulosic biomass to ethanol includes a disruptive pretreatment process followed by enzyme‐catalyzed hydrolysis of the cellulose and hemicellulose components to fermentable sugars. As the cost and hydrolytic efficiency of enzymes are major factors that restrict the commercialization of biomass conversion processes, significant efforts are made nowadays to improve the enzymatic mixtures and make the process cost‐effective. RESULTS: In this work, enzymatic microassays have been developed and validated to test new different enzymatic formulations on real lignocellulosic substrates. Homogeneous handsheets from steam pretreated wheat straw were elaborated to be used as substrate. The microassay was adapted to test both water‐insoluble solids and the whole slurry as substrates. Results in hydrolysis microassays were comparable with those obtained in standard flask assays using pretreated wheat straw. Moreover, using the enzymatic microassays, two novel preparations have been evaluated, demonstrating the ability of microassays to discriminate between different enzymatic mixtures. CONCLUSIONS: This enzymatic microassay represents a rapid method to test the performance of new selected cellulase enzymes on real pretreated lignocellulosic substrates. This microassay will enable evaluation of enzyme components separately, or optimized mixtures. Copyright © 2010 Society of Chemical Industry     

双组分混合有机溶剂中脂肪酶催化反应的热力学分析

将两种不同极性的有机溶剂1,4-二氧六环和正庚烷按不同摩尔比混合，配成具有不同logP值的双组分混合溶剂，以此为反应介质考察了固定化脂肪酶Lipozyme RM IM催化的正丁醇和月桂酸酯化反应的初速度. 同时在与上述混合溶剂具有相近logP值的单一溶剂中进行了类似研究. 实验结果表明，在混合溶剂和单一溶剂中，反应初速度随溶剂极性的变化规律呈现很大差异. 从溶剂混合对反应物热力学活度及反应活化能的影响可以合理地解释这一实验结果.