8％毒死蜱·杀螟单颗粒剂对甘蔗螟虫防治效果试验

以5％特丁硫磷颗粒剂为对照,进行8％毒死蜱·杀螟单颗粒剂对甘蔗螟虫田间防治效果试验。结果显示,在甘蔗松蔸时施用8％毒死蜱·杀螟单颗粒剂2．0～3．0kg ai·ha^-1,药后60、90d对甘蔗螟虫的防治效果均超过75％,与对照药剂5％特丁硫磷颗粒剂3．0kg ai·ha^-1处理的防效相当,差异不显著。因此,生产中建议结合新植蔗播种、宿根蔗松蔸时使用8％毒死蜱·杀螟单颗粒剂防治甘蔗螟虫,推荐使用剂量为2．0-3．0kg ai·ha^-1。     

In vitro and in vivo effects of chlorpyrifos and cypermethrin on blood cholinesterases in sheep

The combination of the organophosphate (OP) chlorpyrifos (CPF) and the pyrethroid cypermethrin (CPM) is commonly marketed as pour‐on formulations for the control of sheep lice, ked, and blowflies. CPF irreversibly inhibits acetylcholinesterases (AChE), while pyrethroids are not AChE inhibitors. However, combinations of pyrethroids with OPs showed a highly synergistic effect on AChE inhibition. Thus, the aim of the current work was to evaluate in vitro and in vivo the inhibitory potency of both pesticides, alone and in combination with AChE and butyrylcholinesterase (BChE) activities in sheep blood. In vitro, IC50 values were similar after CPF or CPF plus CPM incubations. The pour‐on coadministration of recommended doses of CPF and CPM did not cause a significant inhibition of AChE and BChE in sheep blood. Only slight percentages of inhibition of their catalytic activities were observed when both drugs were given at 4‐fold higher dose rates. The lower systemic availability of topical administration of OPs in sheep may help to explain the lower degree of inhibition of blood AChE and BChE in vivo. The results emerged from this research are a further contribution to the knowledge of the risks of implementing higher dosage regimens of OPs‐containing antiparasitic formulations.     

毒死蜱和氰戊菊酯在土壤中的吸附与迁移

为评估被用作白蚁预防药剂的毒死蜱和氰戊菊酯在土壤中的移动性,采用平衡吸附法和薄层层析法分别测定了两种农药在浙江宁波地区的东钱湖土(粉砂质壤土)、青岭土(粉砂质壤土)和象山土(粉砂质黏壤土)3种土壤中的吸附常数(Kd)和迁移率(Rf)。结果表明,两种供试药剂在东钱湖土中的吸附等温线线性化程度均较高,而在青岭土和象山土中的吸附等温线均近似于 "L"型。从Kd和有机质吸附常数Koc的数值看,氰戊菊酯在土壤中的吸附作用主要受土壤有机质因素影响,而毒死蜱的吸附并非只受土壤有机质因素的影响。毒死蜱在3种供试土壤中的Kd和Rf值均高于氰戊菊酯。这表明由Kd值推测不同农药在土壤中的相对移动性可能会存在一定偏差。毒死蜱和氰戊菊酯在3种土壤中的Rf值由大到小的顺序为:东钱湖土>青岭土>象山土;而Kd值由大到小顺序为象山土>青岭土>东钱湖土。对Kd和Rf值与土壤理化性质的多元线性回归分析表明:1)土壤有机质含量和阳离子代换量在决定Kd和Rf值中所起的作用相互重叠;2)土壤有机质含量(或土壤阳离子代换量)和土壤黏粒含量是影响Kd和Rf值的关键因素,而土壤pH值对于Kd和Rf值无决定性影响。     

30.5%毒死蜱·甲氨基阿维菌素苯甲酸盐微乳剂防治小菜蛾田间药效试验

田间试验表明,30.5%毒死蜱·甲氨基阿维菌素苯甲酸盐微乳剂对小菜蛾有良好的防治效果,15～25mL/667m2药后14d防效均达98%以上。     

30．5％毒死蜱·甲氨基阿维菌素苯甲酸盐微乳剂防治小菜蛾田间药效试验

田间试验表明,30.5%毒死蜱.甲氨基阿维菌素苯甲酸盐微乳剂对小菜蛾有良好的防治效果,15～25mL/667m2后14d防效均达98%以上。     

30%毒死蜱·三唑磷乳油的气相色谱测定

本文介绍了毒死蜱和三唑磷2种有效成分在同柱同条件下的气相色谱分离测定方法。毒死蜱和三唑磷的标准偏差分别为0.056和0.090,毒死蜱的回收率为98.04%～102.61%,三唑磷的回收率为97.84%～105.03%。该方法简便、快捷、准确。     

毒死蜱·高效氯氟氰菊酯22%水乳剂的高效液相色谱分析方法

本文叙述了采用高效液相色谱法以乙腈∶水(4∶1)为流动相,C18柱和紫外检测器同时定量分析了混剂中的毒死蜱和高效氯氟氰菊酯的含量。结果表明,毒死蜱和高效氯氟氰菊酯的标准偏差分别为0.124 6、0.021 21;变异系数分别为0.62%、1.03%;平均回收率分别为100.49%、100.36%,线性相关系数分别为r毒死蜱=0.999 7、r高效氯氟氰菊酯=0.999 9。     

Effect of methyl parathion and chlorpyrifos on certain biomarkers in various tissues of guppy fish, Poecilia reticulata

Tests of acute toxicity were performed on the most common species of aquarium fish, Poecilia reticulata. Guppies (P. reticulata) were exposed to progressive concentrations of methyl parathion (MP) and chlorpyrifos (CPF); a semi-static method according to guidelines of OECD was used. Tests of acute toxicity were conducted using 10 fish for each separate concentration and for the control group. The results were subjected to probit analysis to determine the 96 h LC₅₀ values. The 96 h LC₅₀ values of MP and CPF to P. reticulata were 8.48 ppm/L (5.98–10.89) and 0.176 ppm/L (0.313–0.224) respectively. In addition, behavioral changes at each concentration were observed for the individual fish. Fish were exposed for 96 h to different sublethal concentrations of MP and CPF (¼ LC₅₀, 1/8 LC₅₀ and 1/10 LC₅₀) and their oxidative stress-induction potential was estimated in brain, liver and gills of fish. MDA content is induced in all tissues but maximum rise was observed in gills (161% and 153% for MP and CPF respectively). With regard to antioxidant defense system (ADS), GSH level decreased in the brain, liver and gills of tissues of MP treated fishes (22%, 6% and 13% respectively) and showed increase in brain and gills CPF treated (23% and 21% respectively). CAT, GST, GR and SOD levels fluctuated in all treatment groups relative to the control. Brain AChE showed dose-dependent inhibition in fish exposed to the higher concentrations reached 45% and 66% for MP and CPF respectively. Collective findings demonstrated that pesticide exposure of fish induced an increase in MDA and fluctuated ADS along with inhibited AChE. These findings may be used as valuable biomarkers for evaluation of water pollution.     

模拟加工对菠菜中农药残留量及膳食暴露评估的影响

采用田间喷药、室内模拟加工和气相色谱检测方法,研究了水洗、漂烫和烘干处理对菠菜中毒死蜱、氯氰菊酯和氰戊菊酯残留量的影响。结果表明:在田间推荐剂量下,当毒死蜱、氯氰菊酯和氰戊菊酯的有效成分用量分别为0.038 8、0.001和0.01 g/m2时,经水洗和漂烫处理,菠菜中上述3种农药的残留量分别降低22.6%、53.8%和50.8%;而加倍剂量处理时,则分别降低8.5%、61.4%和40.2%;烘干处理对毒死蜱的去除作用大于50%,但对氯氰菊酯和氰戊菊酯的去除作用仅为10%左右。对新鲜菠菜和干制菠菜的农药残留量进行膳食暴露评估的结果表明,合理的加工方式可以降低农药膳食摄入估计量的62.1%~76.7%。研究结果表明:毒死蜱的残留受水洗和漂烫影响较小,受烘干影响较大;而氯氰菊酯和氰戊菊酯的残留受水洗与漂烫影响较大,受烘干影响较小;引入加工因子后膳食暴露评估结果更接近真实值。     

苹果树叶与白三叶叶内毒死蜱残留研究

为了保证畜禽的饲喂安全,测定苹果(Malus pumila)树树叶和白三叶(Tri folium repens)叶内农药含量是否超标,本研究采用气相色谱法,在西北农林科技大学苹果园内取样检测.结果表明,常规剂量时,毒死蜱在苹果树叶内的半衰期是1.8 d,白三叶叶内为2.2 d,2倍剂量时苹果树叶内为1.8 d,而白三叶...