双氧威在土壤及水中残留分析方法

建立了双氧威在土壤及水中的残留分析方法.土壤和水样品分别以丙酮和乙腈提取,高效液相色谱-DAD检测器检测.双氧威的最小检出量为2.0×10-11 g,土壤中的最低检出质量分数为0.03 mg/kg,水中为0.03 mg/L.土壤中双氧威的平均添加回收率为83.5%～100.8%,变异系数为3.2%～6.8%;水中的平均添加回收率为96.2%～100.8%,变异系数为0.7%～2.3%.该方法的准确度、精确度及灵敏度均达到农药残留分析的要求.     

氟草烟在水稻中的残留分析方法

建立了应用衍生化反应测定水稻中氟草烟残留量的气相色谱分析方法.样品采用氢氧化钠甲醇溶液振荡提取,二氯甲烷液-液分配,甲酯化后GC-ECD测定.结果表明:水稻植株、糙米和稻壳中氟草烟的添加回收率分别为88.91%～100.50%、85.51%～92.38%、89.04%～93.02%,变异系数分别为1.86%～6.71%、3.81%～7.04%、6.32%～9.94%;氟草烟的最小检出量为2.0×10-12g,在植株、糙米、稻壳中最低检测质量分数分别0.005、0.01、0.005mg/kg.     

气相色谱法测定噻虫嗪在稻田中的残留

建立了气相色谱法测定糙米、谷壳、植株、土壤和稻田水中噻虫嗪残留量的方法。结果表明,噻虫嗪在0.010 8～1.08 mg/L范围内线性关系良好,相关系数为0.999 8,在各自的添加水平下,噻虫嗪在糙米、谷壳、植株、土壤和稻田水中的平均回收率为83%～107%,变异系数为0.6%～9.8%。噻虫嗪在稻田水中的定量限(LOQ)为0.005 4 mg/L,在糙米、土壤中的定量限均为0.011 mg/kg,在谷壳、植株中的定量限均为0.054 mg/kg。     

22%苄嘧磺隆·五氟磺草胺SC在水稻土壤及稻田水中的残留分析方法

[目的]建立超高效液相色谱串联质谱法检测水稻土壤、稻田水中苄嘧磺隆、五氟磺草胺残留的方法。[方法]土壤中的苄嘧磺隆和五氟磺草胺用乙腈提取,采用Qu ECh ERS法净化,稻田水中的苄嘧磺隆和五氟磺草胺用乙酸乙酯萃取,用Agilent Zorbax RRHD Eclipse Plus C18色谱柱分离,以0.1%甲酸水-乙腈为流动相进行梯度洗脱,流速为0.3 m L/min,采用正离子电喷雾电离模式测定,外标法定量。[结果]方法的线性范围为0.002~1.0 mg/L,相关系数分别为0.9997和0.9999;在0.01、0.05、0.50 mg/L三个添加水平下,水稻土壤中,2种农药的平均回收率为77.1%~103.8%,相对标准偏差为2.4%~8.0%(n=5);在稻田水中平均回收率为77.6%~94.2%,相对标准偏差为2.4%~7.6%(n=5)。在上述检测条件下,苄嘧磺隆和五氟磺草胺的最小检出量分别为6.0×10-3、7.0×10-3ng。[结论]该方法的灵敏度、准确度、精密度符合农药残留分析的要求,适合大批量的水稻样品的检测。     

水稻中氯噻啉的高效液相色谱残留分析方法

样品经二氯甲烷提取.弗罗罩硅土与活性炭混合层析柱净化,高效液相色谱仪分离,紫外270 nm检测.对水稻和环境中的氯噻啉进行不同水平的添加回收率实验,方法的回收率为89.27%～98.11%,变异系数为0.55%～3.64%.氯噻啉的最小检知量为0.2 ng,氯噻啉在稻田水中的最低检出质量浓度为0.0004 mg/L.氯噻啉在土壤、植株、谷壳、稻米中的最低检出质量分数分别为0.005、0.01、0.02、0.035 mg/kg.     

草莓和土壤中啶酰菌胺残留量的高效液相色谱分析

建立了啶酰菌胺在草莓和土壤中的残留分析方法,样品经丙酮提取,二氯甲烷液-液分配,固相萃取小柱净化后,进行高效液相色谱分析.仪器最小检出量为0.1 ng,在草莓和土壤中的最低检出质量分数均为0.02 mg/kg.在草莓中的平均添加回收率为92.3%～94.4%,变异系数为2.64～4.82;在土壤中的平均添加回收率为89.0%～94.3%,变异系数为3.72～5.43.     

氟虫双酰胺在土壤和白菜中的高效液相色谱分析

采用高效液相色谱法分析了土壤和白菜中的氟虫双酰胺,依次用乙腈和正己烷提取土壤和白菜中的氟虫双酰胺,提取液过弗罗里硅土柱净化,以甲醇-水(体积比1:3)作为流动相,使用C18反相色谱柱和紫外可变波长检测器,用外标法进行分析和定量.土壤中氟虫双酰胺的添加回收率为91.31%～94.80%,变异系数为2.57%～8.33%;白菜中氟虫双酰胺的添加回收率为89.19%～103.15%,变异系数为4.21%～5.43%;氟虫双酰胺在土壤和白菜中的最小检出量均为l×10-10g,最低检出质量分数均为0.003 mg/kg.     

噻霉酮在黄瓜和土壤中的残留分析方法

研究并建立了噻霉酮在黄瓜和土壤巾的残留分析方法.黄瓜和土壤样品分别用丙酮和二氯甲烷提取,固相萃取(SPE)净化,液相色谱(LC)测定.噻霉酮的最小检测量为1.0×10-9g,黄瓜和土壤中的最低检出质量分数均为0.01 mg/kg.在0.5～5.0 mg/kg的添加质量分数下,土壤中噻霉酮的平均添加回收率为85.9%～97.2%,变异系数为2.2%～3.8%;黄瓜中的平均添加回收率为89.2%～97.6%,变异系数为1.5%～2.4%.     

苹果和土壤中溴菌腈残留分析方法

研究并建立了溴菌腈在苹果和土壤中的残留分析方法.苹果和土壤样品分别用丙酮、二氯甲烷和甲苯提取,固相萃取(SPE)净化,气相色谱(GC)测定.溴菌腈的最小检测量为2.0×10-11 g,苹果和土壤中的最低检出质量分数均为0.03 mg/kg.在添加0.05～2.5 mg/kg时,土壤中溴菌腈的平均添加回收率为80.4%～105.1%,变异系数为1.9%～8.4%;苹果中的平均添加回收率为80.6%～96.7%,变异系数为2.0%～4.0%.该方法的准确性、精确性以及灵敏度均达到农药残留分析的要求.     

稻田水、土壤和稻米中乙蒜素的残留

建立了稻田水、土壤和稻米中乙蒜素的残留分析方法.样品采用二氯甲烷提取、气相色谱测定.实验结果表明:乙蒜素在稻田水样中的平均添加回收率为85.3%～89.1%;在土壤中的平均添加回收率为90.3%～95.4%;在稻米中的平均添加回收率为87.0%～90.3%.稻田水样、土样、稻米中乙蒜素的最低检测质量分数分别为0.002、0.01、0.02 mg/kg.     

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。