Current- and past-use pesticide prevalence in drainage ditches in the Lower Mississippi Alluvial Valley

BACKGROUND: Pesticide application is common in agriculture and often results in applied pesticides entering adjacent aquatic systems. This study seasonally analyzed a suite of 17 current‐ and past‐use pesticides in both drainage waters and sediments to evaluate the prevalence of pesticides in drainage ditches across the Lower Mississippi Alluvial Valley (LMAV). RESULTS: There were significantly higher concentrations (P < 0.05) of current‐use than past‐use pesticides; however, there were consistently high numbers of detections of past‐use pesticides in sediments. Sediment pesticide concentrations were an order of magnitude higher (150–1035 µg kg^?1) than water samples (6–20.9 µg L^?1). Overall, 87% of all samples analyzed for current‐ and past‐use pesticides were non‐detects. p,p′‐DDT was detected in 47.5% of all drainage waters and sediments sampled. There were significant correlations (0.372 ≥ r²≤0.935) between detected current‐use water and sediment concentrations, but no significant correlations between past‐use water and sediment concentrations. CONCLUSION: Overall, there was a high percentage (87%) of sediment and water samples that did not contain detectable concentrations above the lower limit of analytical detection for each respective pesticide. This lack of pesticide prevalence highlights the improved conditions in aquatic systems adjacent to agriculture and a potential decrease in toxicity associated with pesticides in agricultural landscapes in the LMAV. Copyright © 2011 Society of Chemical Industry     

Toxicology of insecticides to mammals

Many insecticides target structures or functions in non-target species, including mammals. This is particularly true of those that target the insect nervous system, such as the organochlorines, anticholinesterases and GABA antagonists. Another group of insecticides target structures or functions not present in mammals, and this group of insecticides has considerable target species specificity, but there are often potential targets in mammals. Octopamine is closely related to adrenaline and amitraz (an octopamine receptor agonist) and acts in mammals at α2-adrenergic receptors. Although there are potential targets in mammals for juvenile hormone mimics and ecdysone receptor agonists, there is no evidence that the mammalian toxicity of either group is related to their insecticidal activity. Nor do chitin synthesis inhibitors have high mammalian toxicity. Copyright © 2012 Society of Chemical Industry     

固相萃取-气相色谱法测定水中的有机磷农药

[目的]建立水中有机磷农药的测定方法。[方法]使用气质联用仪对样品进行质谱定性,气相色谱(PTD检测器)定量,试验不同的萃取方法及水样的酸碱度对回收率的影响,并对不同净化柱的净化效果进行对比。[结果]该研究降低了水样假阳性的检出率,平均回收率控制在80.0%～100.0%,检出限小于5.0 ng/L。[结论]该研究为地下水样品有机磷农药残留的定性定量检测提供了一套实用的方法。     

五自由度采摘机械臂运动学通用算法应用

通过建立通用采摘机械臂运动学模型,构造初始矢量方程,完成求解,验证了基于Groebner基法的运动学算法的可行性,为采摘机械臂结构设计与控制研究提供了参考数据。     

绿豆尾孢菌叶斑病田间药剂防治试验

试验研究了3种杀菌剂10种处理对绿豆尾孢菌叶斑病的防治作用,结果表明,用25%嘧菌酯悬浮剂500倍液浸种2 h+25%嘧菌酯悬浮剂600倍液喷雾、25%多.霉威悬浮剂500倍液浸种2 h+25%多.霉威悬浮剂600倍液喷雾、25%戊唑醇乳油500倍液浸种2 h+25%戊唑醇乳油600倍液喷雾,相对防效分别为87.23%,84.85%,82.29%,防治效果较好,是防治绿豆尾孢菌叶斑病较理想的药剂,且具有一定的增产效果。建议生产上配合其他药剂交替使用。     

稻田土壤、植株和大米中的农药残留分析

建立了气相色谱-质谱法检测稻田土壤、植株和大米中的12种农药残留分析方法。样品经乙腈提取,Florisil层析小柱净化,气相色谱-质谱法检测。12种农药均具有良好的线性关系,相关系数不低于0.998,1.0、0.10、0.05 mg/L 3个浓度混合标准溶液的加标回收率为90.5%～101.2%,相对标准偏差为2.1%~4.7%,检出限为0.005~0.015 mg/L。该方法具有检测结果准确可靠、简便快速等优点。     

我国农药制造业发展现状及对策研究

近年来,我国农药制造业发展出现了喜人的局面:农药总产量跃居世界第一,农药出口总量得到提升,农药生产技术水平逐年提高。但是农药行业仍存在小而分散、农药产品质量不高、研发能力弱等问题。可通过建立农药产业园、增加研发投入等手段来解决我国农药行业现存的问题。     

拟除虫菊酯类农药的酶水解研究进展

近年来的研究发现,拟除虫菊酯类农药对人体会产生“三致”作用.而酶催化农药水解作为去除此类农药污染的有效手段,逐渐成为环境科学研究热点.文章结合分析拟除虫菊酯类农药的水解机制,综述近年来国内外拟除虫菊酯类农药的酶水解研究进展,并对其发展趋势作以展望     

菠菜中10种有机磷农药残留的气相色谱检测

为提高菠菜中有机磷类农药残留的检测准确率,采用加标回收的方式,在未检出农药的新鲜菠菜中分别加入3个浓度梯度的敌敌畏、甲胺磷、氧化乐果、毒死蜱等10种常见有机磷农药,按照NY/T 761-2008方法处理。经气相色谱检测,10种有机磷农药的平均回收率为77.4%~107.9%,相对标准偏差为1.1%~8.5%,最低检出限为0.007~0.019 mg/kg。试验所有结果均符合国家农药残留量测定方法的要求。     

4种大蒜富硒能力的比较研究

研究了金乡杂交蒜、嘉祥红皮蒜、苍山蒲棵蒜、金乡白蒜在2种施硒培养方式下的富硒能力。结果表明,在叶面施硒方式下,金乡杂交蒜的总硒含量为1.346mg/kg;嘉祥红皮蒜的有机硒含量为1.247mg/kg,有机硒转化率为96.3%。水培施硒方式下,金乡杂交蒜的总硒含量可达2.512mg/kg;嘉祥红皮蒜的有机硒含量为0.632mg/kg,有机硒转化率为35.5%。不同大蒜品种富硒能力存在显著差异,金乡杂交蒜的总硒富集能力最强,嘉祥红皮蒜的有机硒富集转化能力最强。