共查询到18条相似文献，搜索用时 125 毫秒
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毒死蜱在表面活性剂混合体系中的增溶规律及其药效评价 总被引：4，自引：0，他引：4
为明确表面活性剂在农药制剂微乳化中的作用和评价农药制剂微乳化对药剂生物效果的影响,通过测定毒死蜱在有机溶剂-表面活性剂混合体系中的最大增溶浓度和在不同表面活性剂 /水微乳体系中的最高浓度,研究了毒死蜱在表面活性剂混合体系中的增溶规律,得到了毒死蜱微乳剂的优化配方,并对30%毒死蜱微乳剂对棉铃虫Helicoverpa armigera的生物活性进行了室内外药效试验。结果表明:毒死蜱在有机溶剂-表面活性剂混合体系中的最大增溶浓度和在有机溶剂-表面活性剂-水微乳体系中的最高浓度分别随体系中表面活性剂浓度和表面活性剂 /水(质量比)的增加而增大,但表现出不同的增溶规律;优化后的毒死蜱微乳体系分散液滴呈球形,流体力学半径约25.9 nm;30%毒死蜱微乳剂与40%毒死蜱乳油对棉铃虫的室内LC50值分别为500和561 mg/L,无显著差异;在相近有效使用剂量下,微乳剂的田间防效并未比乳油显著提高。研究表明,保证制剂中足够的表面活性剂质量分数是农药制剂微乳化形成与稳定的关键,农药制剂微乳化带来的农药有效成分分散度提高并不能显著提高药剂的生物活性。 相似文献
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1、乳油类农药的标准中为什么要有乳液稳定性技术指标? 乳油制剂是将农药原药用一种有机溶剂溶解后(有的液体原药可不用溶剂),再混入一定比例的乳化剂配制而成的。乳油加水稀释形成乳浊液即可喷施。农业上应用的乳油加水后绝大多数形成水包油型的乳液。也就是农药的有机溶液在乳化剂的作用下以油珠的形式悬浮在水中,要求油珠在较长的时间内能均匀地悬浮分散在水中,以保持在喷施过程中有效成分 相似文献
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农药乳油中含有苯、甲苯、二甲苯等有害有机溶剂，这些溶剂闪点低、易挥发、毒性高，对生态环境和人类健康具有潜在风险。本文主要综述了农药乳油中有机溶剂的使用现状、危害及可能的解决措施，重点介绍了以生物源溶剂、矿物源溶剂、人工合成溶剂替代乳油中有害有机溶剂的研究进展。这些替代溶剂低毒、环保，在乳油中具有很好的应用前景，但通过实验筛选替代溶剂通常费时费力，而热力学模型COSMO-RS可以从理论上预测替代溶剂对农药的溶解性，再通过实验加以验证，省时省力，可加快乳油中替代溶剂的筛选，对开发环境友好型乳油具有指导意义。 相似文献
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随着农药施药器械的发展、新成分及高含量制剂的研发，农药单位面积上的使用剂量越来越低，因此，农药制剂的稀释与配制尤其重要。在农药中，以“稀释后喷雾使用”的剂型最常见，包括乳油、可湿（溶）性粉剂、悬浮（乳）剂、水乳剂、水剂、微乳剂、水分散粒剂等，现介绍农药制剂的高质量稀释方法。 相似文献
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“七五”期间我国农药加工技术发展回顾 总被引：1，自引：0，他引：1
为了加速我国农药加工工业的发展,改变我国农药制剂品种少、质量差、助剂不配套、加工设备落后的状况。在“七五”期间,国家计委将农药新剂型新制剂开发列入科技攻关计划。其指导思想是通过攻关,使我国农药含剂质量,特别是可湿性粉剂和乳油的质量,达到或超过联合国粮农组织(FAO)规定的指标;增加新剂型和新制剂品种。要求开发50个农药新制剂和4种 相似文献
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农药制剂的有效成分含量是表示制剂中杀菌、杀虫的有效成分的量,通常用百分数来表示,如50%乳油是指该制剂中的有效成分为50%。含量不同用药量不同。如用25%的乳油每亩20ml,改用该制剂50%的乳油时,用药量只需10ml。再如每亩用40%乙磷铝可湿性粉剂200—300倍液,亩用液50kg,防治 相似文献
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关于农药乳油制剂的酸碱性技术指标 总被引：1，自引：0，他引：1
我国农药制乳油剂酸碱性技术指标以往多用酸度表示，高效氯氰菊酯，溴氰菊酯，氯氟氰菊酯等乳油不同酸度或ｐＨ值的制试样热贮试验表明，对介质酸碱性较敏感的有效成分乳油制剂，质量控制应采用严格的ｐＨ值范围作为技术指标。 相似文献
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确定农药对高等动物毒性和杀虫效力的LD_(50)值(即致死中量)过去都是以农药纯品求得的。直接使用的商品农药如乳油、粉剂等,原药含量不一,有些制剂尚含有毒性较低的溶剂或助剂,因此制剂的LD_(50)值与原药的LD_(50)值应有差别。 据世界卫生组织(WHO)推荐的《农药毒性分级》使用说明,我们对农药制剂的LD_(50)值进行探讨,为选择溶剂或助剂提供依 相似文献
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在以50mm长的反相液谱短柱上实现了上辛硫磷乳油和神光乳油中辛硫磷的HOLC／UV快速分析,该方法的密度为辛硫磷乳油中辛硫磷的相对标准偏差4．3％,神光乳油中辛硫磷的RSD是3．65;辛硫磷乳油中辛硫磷的回收率102．5％,神光乳油中辛硫磷的回收率99．6％,为辛硫磷乳油和神光乳油中辛硫磷的仪器检测提供了一种经济、快速而又准确,可靠的方法。 相似文献
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用喷雾法防治油菜田茴香薄翅野螟,结果表明：0.5%甲氨基阿维菌素苯甲酸盐微乳剂、4.5%高效氯氰菊酯乳油、2.5%高效氯氟氰菊酯乳油和200 g/L氯虫苯甲酰胺悬浮剂4种农药对茴香薄翅野螟的防效随着施药次数增加而增加;40%灭多威可溶性粉剂和25%杀虫双水剂的防效随着施药次数的增加防效逐渐下降; 48%毒死蜱乳油在不同施药次数下防效变化幅度较小,平均防效在95.85%左右;上述7种农药喷施1次后, 以48%毒死蜱乳油和40%灭多威可溶性粉剂的防效最好,分别达96.03%和94.82%。4.5%高效氯氰菊酯乳油、2.5%高效氯氟氰菊酯乳油和48%毒死蜱乳油喷施2次和3次时的防效都在95.70%左右。 相似文献
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Metal drums of various sizes which had contained a parathion emulsifiable concentrate were found to retain significant amounts of residues after the containers were completely drained. The residual pesticide formulation was removed from the emptied containers by washing with water and organic solvents. Efficient removal of the parathion by water followed by washing with a water-miscible organic solvent has been demonstrated. It is possible that these washings could be disposed of by combining them into the spray mixture. These procedures suggest a simple and economical way of container decontamination. 相似文献
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Studies were carried out on the rodenticidal effect of Nuvacron (40% emulsifiable concentrate) applied in 5 different dosages to clover crops and natural pastures subjected to high population densities of Microtus arvalis (Pallas). The mechanical application of a single treatment per year (late in September) with Nuvacron 40% emulsifiable concentrate, at the rate of 3.51/6001 water/ha, resulted in a low density of this pest. Similar results were also obtained when the pesticide was tested on a 35 ha area, under commercial conditions. Consequently, its use is recommended for the control of M. arvalis in alfalfa and clover seed crops. 相似文献
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The volatility of tri-allate from different formulations when mixed with 2 soils containing water at 2%, 6% and field capacity was estimated in the laboratory. Volatility increased with increasing water content in each case. It was generally highest from an emulsifiable concentrate and lowest from a granule formulation with that from unformulated tri-atlate intermediate. In a greenhouse experiment rates of loss of tri-allate from a dry soil were similar for both emulsifiable concentrate and granule formulations, but from a wet soil and an aluminium foil dish losses were much greater from the emulsifiable concentrate. The persistence of trii-allate from granules applied in the field was virtually the same for granules containing 2.5, 5 or 10% active ingredient. 相似文献
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A colorimetric method for the determination of the stability of dilute emulsions (down to 1 ml litre?1) of emulsifiable concentrates (EC) has been subjected to a collaborative study with 27 participating laboratories, on behalf of the Collaborative International Pesticides Analytical Council (CIPAC). A dye is added to the emulsifiable concentrate and an aliquot is poured into standard water to obtain an aqueous emulsion. After a specified time, the absorbance of an aliquot of the dyed emulsion is measured and compared to the absorbance measured after initial formation of the emulsion. Collaborators were furnised with four emulsifiable concentrate formulations and the dye, and requested to make three replicate determinations on each dyed sample in CIPAC standard waters A and D. The repeatability and reproducibility figures obtained in these trials indicate that the method permits a good estimation of the stability of dilute emulsions when it is followed exactly. 相似文献