三元复配制剂杀虫威的分析方法研究

本文采用气相色谱法，在一根５％ＱＦ－１填充上，以邻苯二甲酸二乙酯和荧蒽为内标，在适宜的色谱条件下对三元复配制剂杀虫威进行分析。方法的变异系数：甲胺磷为０．７３％，异丙威为０．６５％，噻嗪酮为０．５２％。回收率：甲胺磷为９９．０～１００．２％，异丙威为９９．１～９９．７％，噻嗪酮为９９．２～１００．４％。     

40%柴.哒乳油中哒螨灵的气相色谱

采用气相色谱法，对４０％柴．哒乳油中哒螨灵进行了定量分析。其标准曲线方程为Ｒｓ＝０．７１１２Ｒｍ＋０．０３９８，相关系数为０．９９９６。方法回收率为９９．２％－１００．１％，标准偏差为０．０２％ 异系数为０．４０％。     

反相高效液相色谱法测定快杀稗

选用反相高效液相色谱法，在Ｃ１８反相柱上，以甲醇／ｐＨ３．０水为流动相，以邻苯二甲酸二乙酯为内标物，对快杀稗进行定量分析，９次测定结果，其平均值为８８．７４％，相对偏差为０．３７％，变异系数为０．６３％，平均回收率为９９．１％－１０１．９％，线性相关系数为０．９９９９７。     

灭幼脲悬浮剂的高效液相色谱分析

采用高效液相色谱法，使用反相色谱柱和紫外检测器，以二甲基甲酰胺为溶剂，邻苯二甲酸二丁酯为内标物，对灭幼脲悬浮剂进行分析测定。方法的标准偏差０．０３４，变异系数０．５２％，相关系数０．９９９９，回收率９９．１％￣１００．２％。     

反相高效液相色谱法测定快杀稗

选用反相高效液相色谱法，在Ｃ１８反相柱上，以甲醇／ｐＨ３．０水（６５／３５ｖ／ｖ）为流动相，以邻苯二甲酸二乙酯为内标物，对快杀稗进行定量分析。９次测定结果，其平均值为８８．７４％，相对偏差为０．３７％，变异系数为０．６３％，平均回收率为９９．１％～１０１．９％，线性相关系数为０．９９９９７。     

三唑磷的气相色谱分析

用３％ＯＶ－１０１的气相色谱填充柱，以邻苯二甲酸双环己酯为内标，用具有氢焰离了化检测器的气相色谱仪对三唑磷原药和油进行了定量分析。原药和乳油的标准偏差分别为０．３和０．２，变异系数分别为０．４％和０．７％，方法的平均回收率为９９．７％，此法操作简便、变量准确。     

火焰原子吸收法测定橡胶中的铅

用ＧＦＵ－２０１原子吸收分光光度计对测定橡胶中的铅进行试验研究。测量条件：波长，２８３３；空气流量４．４Ｌ／ｍｉｎ；乙炔流量１．３Ｌ／ｍｉｎ。消除干扰选用０．３％碳酸钙、０．２％Ｆｅ２Ｏ３和０．１５％钾。灵敏度为０．３×１０－６，相对误差±２．３％，均方差０．００００３６％。     

反相离子对高压液相色谱法测定二氯喹啉酸的含量

应用反相离子对高压液相色谱法对二氯喹啉酸原药进行了定量测定，获得满意的结果，方法的标准偏差为０．３１％，变异系数为０．３８％，回收率为９９．１１％～１０２．６１％。     

对-甲氧基苯丙烯腈气相色谱分析

使用１０％ＳＥ－３０为固定液的２ｍ长填充柱，以硝基苯为内标物，对对－甲氧基苯丙烯腈进行快速，准确的气相色谱定量分析。其线性相关系数为０．９９９２，回收率达９８％～１０２％，平行测定的标准偏差为０．２５％～０．２８％，变异系数为０．２９％～０．３１％。     

甲氰菊酯的气相色谱分析

用３％ＯＶ－１０１的气相色谱填充柱，以磷酸三苯酯为内标，用具有氢焰离子化检测器的气相色谱仪对甲氰菊酯原药和乳油进行了定量分析。原药和乳油的标准偏差分别为０．５９和０１１，平均变异分别为０．６５％和０．５２％，平均回收率分别１００．２％和９９．２％，此法操作简便，定量准确。     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

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.