气相色谱法同时检测青菜中毒死蜱和氯氰菊酯残留量的方法研究

为更准确、简便地检测青菜中毒死蜱与氯氰菊酯残留,采用气相色谱-微池电子捕获检测器法(GC-μECD),建立了同时测定青菜中这2种农药残留量的分析方法。样品采用乙腈超声提取,过弗罗里硅土固相萃取柱净化,用丙酮/正己烷（1：9,V/V）淋洗,淋洗液水浴蒸发近干后以正己烷定容,应用HP-5毛细管柱程序升温分离,微池电子捕获检测器测定,外标法定量。毒死蜱和氯氰菊酯的线性范围分别为0.005~5mg/L和0.01~5 mg/L,相关系数（r）均大于0.99,添加浓度在0.1~1mg/kg时,平均回收率为84.2%～116.9%,相对标准偏差（RSD）为2.4%~12.7%,检出限分别为0.0002mg/kg和0.003 mg/kg。该方法简便、快速、灵敏,准确度及精密度均满足农药多残留检测的要求,适用于青菜中毒死蜱和氯氰菊酯残留量的检测分析。     

绿色农药氯氰菊酯微乳剂配方原料筛选

[目的]优化绿色农药氯氰菊酯微乳剂配方。[方法]采用乳化水加油法配制氯氰菊酯微乳剂,通过溶解性试验、紫外-可见分光光度法、浊点测定法以及外观、热贮稳定性、冷藏稳定性试验对溶剂、表面活性剂以及助表面活性剂进行了筛选。[结果]2-丁酮、正丁酸乙酯对氯氰菊酯原药的溶解效果最理想,最佳比例为：2-丁酮∶氯氰菊酯=3∶1;正丁酸乙酯∶氯氰菊酯=3∶1。可进行进一步复配试验的表面活性剂有TX-100、CTAB、葡萄糖酯和SDBS。增溶效果最好的助表面活性剂是正丁醇。[结论]为开发水基型、生物相容性良好的氯氰菊酯微乳剂提供了参考。     

Resistance of beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) to endosulfan,organophosphorus and pyrethroid insecticides in Pakistan

Field populations of beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), from Pakistan were assessed for their resistance to the chlorinated hydrocarbon endosulfan, the organophosphates chlorpyrifos and quinalphos, and the pyrethroids cypermethrin, deltamethrin, bifenthrin and fenpropathrin. Using a leaf-dip bioassay, resistance to endosulfan was high during 1998–2000 but declined to very low, to low levels during 2001–2007, following a reduced use of the insecticide. Organophosphates and pyrethroids were consistently used over the past three decades, and the resistance had been increasing to these insecticide classes. Generally, the resistance to chlorpyrifos and pyrethroids remained low from 1998 to 2002–2003, but resistance increased to moderate to high levels from 2003–2004 to 2006–2007. For deltamethrin, resistance was very high during 2004–2007. Quinalphos resistance remained low during 1998–2006. Correlation analysis of LC₅₀ and LC₉₀ values showed a positive correlation between organophosphates and pyrethroids, but no correlation between endosulfan and organophosphates or pyrethroids tested herein. These results suggest that the conventional chemistries should be replaced with new chemistries for the successful management of S. exigua.     

家蚕经菊酯类农药诱导后脂肪体蛋白的表达谱及烯醇酶基因的组织转录活性

为了从蛋白质水平探讨家蚕对菊酯类农药的抗性机制,采用双向电泳结合基质辅助质量飞行时间质谱(MALDI-TOF-MS)技术,分析家蚕5龄幼虫经氯氰菊酯诱导前后脂肪体蛋白的表达特征。采用ImageMaster6.0软件分析表明,对照组共检测到432个蛋白点,诱导实验组检测到369个蛋白点,其中能匹配的蛋白点有342对,匹配率为76.68%。对特征蛋白进行MALDI-TOF-MS分析鉴定的蛋白包括烯醇酶、线粒体醛脱氢酶、伴侣素、肌动蛋白、gag-like蛋白。烯醇酶(enolase)是糖酵解过程中极为重要的酶类。采用半定量RT-PCR对经氯氰菊酯诱导后的家蚕脑、中肠、丝腺、脂肪体、精巢、马氏管、血液等7个组织器官的烯醇酶基因进行表达分析,结果表明,烯醇酶基因转录水平在7个组织器官中都呈现下调趋势,分别下调了13.79%、10.71%、22.48%、7.40%、27.00%、11.50%、14.52%,其中脂肪体的烯醇酶基因表达和蛋白的表达下调一致。受菊酯类农药诱导的影响,家蚕5龄幼虫脂肪体蛋白的数目减少,烯醇酶基因在各组织器官减量表达,提示可能与蚕体的基础生理代谢受到抑制有关。     

Residues of cypermethrin,fenvalerate and deltamethrin on cauliflower

Following the application of Cypermethrin, fenvalerate and deltamethrin to a cauliflower crop at rates of 50, 50 and 12 g a.i. ha^-1, the maximum initial deposits of these insecticides on heads and leaves were 1.10 and 0.75, 1.14 and 0.60, and 0.32 and 0.12 mg kg^-1, respectively. These residue values for fenvalerate were less than the maximum residue limit (MRL) of 2 mg kg^-1 for this crop. While the maximum initial deposits of Cypermethrin and deltamethrin on cauliflower leaves were less than their respective MRL values of 1 and 0.2 mg kg^-1 for brassica leafy vegetables, it took one day for their residues on cauliflower heads to decline below this level.     

L—刀豆氨酸对菜蛾氯氰菊酯敏感品系与抗性品系幼虫的毒力测定

在室内人工饲养菜蛾氯氰菊酯敏感品系与抗性品系.通过人为施用氟氰菊酯,使抗性品系得以保持.通过试验分别获得氯氰菊酯在两品系幼虫的LC_(50)L—刀豆氨酸,产生子刀豆种子的非蛋白毒性氨酸对两品系皆表现药效.通过饲喂法测得L—刀豆氨酸在敏感与抗性品系幼虫的LC_(50).分别为18.11μg/cm~2与20.99μg/cm~2.试验结果表明两品系对L—刀豆氨酸具有近乎相同的敏感程度.此项研究为克服菜蛾业已形成的对拟除虫菊酯类的抗性和利用遗传工程使寄产本身产生刀豆氨酸以抵御害虫侵袭奠定了理论基础.     

Financial analysis of animal trypanosomiasis control using cypermethrin pour-on in Kenya

The financial impact of use of cypermethrin pour-on (Ectopor^R) in control of animal trypanosomiosis was determined in a trial undertaken by the Kenya Trypanosomiasis Research Institute (KETRI). This trial started in December 1990 and ended in February 1992. It was undertaken in two adjacent ranches in the coast province of Kenya. The trial site was in an area of high apparent density (AD) of tsetse flies, and at the start of the trial no cattle were kept in this area. Cypermethrin was applied fortnightly to the 1100 steers which were kept in pour-on ranch ‘A’ while another 100 steers were kept in control ranch ‘B’ to act as control sentinels. From the main pour-on group, 100 animals were identified as the pour-on sentinels and compared to the control sentinels which received no pour-on.

Pour-on application led to a significant decrease in the tsetse AD in the pour-on ranch A to 90% of the initial AD in some areas. The animals treated with pour-on had a significantly higher mean packed-cell volume (PCV). The weekly prevalence of trypanosome infections in animals treated with pour-on was <4% with only one exception when it was <10%. In the control animals, the prevalence ranged between 10 and 50% (with a few exceptions when it was <10%). The incidence of tick-borne diseases was lower in the pour-on animals. The mean monthly weights of the pour-on animals was significantly higher, and at the end of the trial the pour-on animals had a mean weight gain of 136.70±16.7 kg while the control animals had gained 97.16±22.6 kg.

The financial net return of using cypermethrin pour-on was positive and the financial rate of return of 122.6% indicated that use of the pour-on was highly beneficial despite the high cost of the product.     

氯氰菊酯降解菌的分离与筛选

从郑州力克农药厂长期堆放回收农药瓶子处、排污水口处、沉淀池内、堆放成品药品处、工厂周围长期受农药污染的土壤中分别采集了5份混合土样。通过对5种土样的分离、筛选，发现排污口的污泥和沉淀池内的土样所分离、筛选的氯氰菊酯降解菌数量相对较多；其中在土样3中分离出了高效降解氯氰菊酯菌株3—7，经鉴定，该菌为革兰氏阴性球菌，在通气、28℃、pH7．5条件下培养7d，对氯氰菊酯农药（250mg／L）的降解率为78．1％。     

2.4%阿维·氯氰微乳剂的研究

介绍了阿维菌素与氯氰菊酯混配的一种新剂型品种——2.4％微乳剂,简述了该剂型的特点、贮藏稳定性、质量指标及药效试验结果,表明该微乳剂成本低、药效好、使用安全、具有良好开发应用前景。     

氯氰菊酯与p53-DNA相互作用的光谱研究

采用紫外、荧光分光光度法研究了农药氯氰菊酯与人类肿瘤抑制基因p53-DNA之间的相互作用.实验出现紫外减色、荧光猝灭等结果表明氯氰菊酯可能是以嵌插模式与p53-DNA结合作用;紫外变温实验得出p53-DNA熔点温度略有升高等结果则进一步证实氯氰菊酯是部分嵌插入DNA的沟区,影响了DNA的双螺旋结构的稳定性.