20%啶虫脒可溶液剂在棉花和土壤中的残留及消解动态

[目的]评价啶虫脒在棉花和土壤中使用的安全性,建立其使用规范。[方法]采用田间试验及液质联用检测方法,研究了啶虫脒在棉花和土壤中的残留消解动态,并对其在棉花上使用的安全性提出了建议。[结果]啶虫脒在棉花和土壤中的消解较快。棉叶中半衰期为2.14～5.37 d,土壤中半衰期0.88～8.87 d。20%啶虫脒可溶液剂防治棉花蚜虫,用药量30～45 g a.i./hm2,棉花收获前49 d开始施药,末次施药后7、14、21 d采集棉籽及土壤样品,检测的棉籽及土壤中啶虫脒的残留量均低于0.05 mg/kg。[结论]拟推荐我国啶虫脒在棉花和土壤中的最大残留限量为0.2 mg/kg。     

固相萃取-气相色谱法测定葱中啶虫脒的残留量

建立了葱中啶虫脒残留量的气相色谱检测方法. 样品经乙腈提取浓缩后,Florisil固相萃取柱净化,使用HP -5MS毛细管色谱柱进行气相色谱(ECD)分析,采用外标法定量. 在0.01～0.1 mg/kg添加水平范围内,葱样品中啶虫脒回收率为85.9%～106.8%,相对标准偏差为6.1%～7.9%,方法最低检出质量分数为0.01 mg/kg.     

啶虫脒和杀虫环在节瓜中的残留测定

[目的]探讨啶虫脒和杀虫环在节瓜中的残留分析测定,为节瓜中啶虫脒和杀虫环残留量检测提供技术参考。[方法]以乙腈在酸性条件下超声提取,氨基小柱(NH2,500 mg/6mL)净化,高效液相色谱仪检测啶虫脒,气相色谱仪检测杀虫环。[结果]啶虫脒在0.05~5.0 mg/L范围内呈良好的线性关系(r=0.9999),方法的添加回收率为82.4%~85.5%,RSD为4.80%~5.54%;杀虫环在0.01~1.0 mg/L范围内呈良好的线性关系(r=0.999 9),方法的添加回收率为89.4%~97.4%,RSD为4.42%~7.34%。[结论]结果符合国家标准农药残留分析方法测试要求,可为中国节瓜等农产品中啶虫脒和杀虫环残留量检测提供技术参考。     

啶虫脒和吡丙醚在茶叶中的残留行为与膳食风险评估

[目的]探索茶叶中啶虫脒和吡丙醚的残留行为和可能存在的膳食摄入风险。[方法]以27%啶虫脒·吡丙醚可分散液剂按32.55 g a.i./hm²进行叶面均匀喷雾施药1次，进行8个地域的规范残留试验。采用QuEChERS方法进行样品前处理，超高液相色谱串联质谱法对茶叶中的啶虫脒和吡丙醚残留量进行定量分析，研究啶虫脒和吡丙醚农药的最终残留和消解动态，评价啶虫脒和吡丙醚对中国人群的急性和慢性膳食摄入风险。[结果]田间试验表明：啶虫脒和吡丙醚的消解符合一级动力学方程，啶虫脒在重庆和安徽2地茶鲜叶中的降解半衰期为5.00、5.91 d，吡丙醚在2地的半衰期为1.26、5.48 d；末次施药后14、21 d，啶虫脒在茶鲜叶和茶干叶中的残留量为2，施药1...     

啶虫脒在保护地和露地菠菜上的残留量对比研究

采用田间试验及气相色谱检测方法,研究了啶虫脒在上海和天津保护地及露地2种种植模式下菠菜上的残留量。结果表明:2个不同生产地域,啶虫脒在保护地菠菜上的残留量均高于露地。推断光强、降雨和风是造成啶虫脒在保护地和露地上残留量差异的主要因素。     

啶虫脒在茉莉花上的残留动态及膳食风险评估

基于超高效液相色谱-串联质谱仪(LC-MS/MS)及优化的样品前处理技术,建立茉莉花[Jasminum sambac (L.) Ait]中啶虫脒的检测方法。在0.01～0.5 mg/kg添加范围内,茉莉花鲜样和干样中啶虫脒的平均回收率分别为84.0%～93.4%和82.0%～92.4%;相对标准偏差分别为0.6%～6.5%和2.1%～5.5%,定量限均为0.01 mg/kg。结果显示,啶虫脒在茉莉花中的消解动态均符合一级动力学方程,半衰期(t_(1/2))为1.5～1.8 d,施药7 d后采样检测,结果为啶虫脒在茉莉花鲜样和干样中的最终残留量分别不大于0.15 mg/kg和不大于0.11 mg/kg。膳食风险评估结果表明,安全间隔期时普通人群啶虫脒的国家估算每日摄入量为0.925 mg/kg,风险概率即占日允许摄入量为21.0%,对一般人群的健康不存在高风险,拟推荐啶虫脒在茉莉花鲜样和干样上的最大残留量值(MRL)分别为0.5、0.3 mg/kg。     

啶虫脒在苹果和土壤中的残留及消解动态

应用气相色谱(电子捕获检测器-ECD)测定,研究了20%啶虫脒SP在苹果和土壤中的残留消解动态。结果表明,啶虫脒在苹果中半衰期为2.2～5.1d,在土壤中为0.14～2.6d。用量0.2g/L,施药一次,距最后一次施药21d收获苹果中啶虫脒残留量小于0.12mg/kg,建议20%啶虫脒SP在苹果上防治绣线菊蚜最多使用一次,用量为0.1～0.2g/L,安全间隔期为21d。     

45%啶虫脒·杀虫单可溶粉剂成分啶虫脒在椰树上的残留动态

[目的]为了明确45%啶虫脒·杀虫单可溶粉剂挂袋于椰树后,其成分啶虫脒对椰心叶甲的有效性及椰果的食用安全性。[方法]利用挂袋法把粉剂应用于海南椰树上,借助高效液相色谱检测施药后10、20、30、40、50、60 d的样品中啶虫咪含量。[结果]施药2个月内,啶虫脒在椰树心叶上的残留量在45.60～92.25 mg/kg之间,在椰果中没有被检测到。[结论]45%啶虫脒·杀虫单可溶粉剂挂袋后2个月内,啶虫脒在椰树心叶中的最低含量高于椰心叶甲的有效防治质量分数,既确保对椰心叶甲的防效,又保障椰子的食用安全性。     

啶虫脒在水稻和稻田水土中的残留及消解动态

应用气相色谱(电子捕获检测器–ECD)测定,研究了25%啶虫脒水分散粒剂在水稻和稻田水土中的残留消解动态。结果表明,啶虫脒在植株中消解半衰期为2.42～3.11d,在稻田水中为1.13～1.81d,在土壤中为2.39～2.75d。有效成分用量36g/hm2,施药2次,距最后一次施药14d收获糙米中啶虫脒的残留量小于0.2mg/kg。建议25%啶虫脒水分散粒剂在水稻上防治最多使用2次,用量为36g/hm2,安全间隔期为14d。     

气相色谱法同时检测烟田中残留的啶虫脒和杀螟硫磷

[目的]建立同时检测啶虫脒和杀螟硫磷在烟田样品中残留量的气相色谱检测方法。[方法]样品采用乙腈进行提取,经弗罗里硅土层析柱净化,用电子捕获检测器进行测定。[结果]当啶虫脒和杀螟硫磷添加质量浓度为0.05~1.00 mg/L时,其添加回收率在92.2%~109.4%之间,相对标准偏差(RSD)在0.02%~3.26%之间。[结论]该方法的前处理过程较为简单,达到了残留分析要求,可用于烟田样品中啶虫脒和杀螟硫磷残留量的测定。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。