嘧草醚原药的高效液相色谱分析

[目的]建立一种用高效液相色谱测定嘧草醚的定量分析方法.[方法]采用C18色谱柱,以乙腈-水(体积比为60∶40)为流动相,流量为0.5 mL/min,柱温为30℃,选择254 nm为检测波长进行检测.[结果]方法的线性相关系数0.9998,标准偏差为0.33,平均回收率为100.30％.[结论]方法简便、快速、能进行准确定量分析,结果稳定.     

粉唑醇的高效液相色谱分析

[目的]建立了一种用高效液相色谱测定粉唑醇的定量分析方法.[方法]采用C18色谱柱,以甲醇-水(体积比为60:40)为流动相,流量为1.0 mL/min,柱温为25℃,选择220 nm为检测波长进行检测.[结果]方法的线性相关系数0.9997,标准偏差为0.28,平均回收率为99.60%.[结论]该方法简便、快速、能进行准确定量分析,结果稳定.     

气相色谱方法测定大豆中丙环唑残留

[方法]研究了丙环唑在大豆中的残留分析方法.样品用乙腈提取,弗罗里硅土净化,采用DB-5ms毛细管色谱柱气相色谱-电子捕获检测器法进行测定.[结果]在该条件下,其最小检出质量分数为0.02 mg/kg,平均添加回收率为85.5％～108.2％,相对标准偏差为4.9％～18.4％.[结论]建立了一套快速、简便、灵敏的大豆中丙环唑残留气相色谱检测方法.     

土壤中克百威的动态变化及其对蚯蚓的毒性

[目的]探究不同质量分数克百威在土壤中的动态变化及其对非靶标生物的影响.[方法]采用自然土壤法研究了克百威对蚯蚓的急性毒性,固相萃取高效液相色谱柱后衍生法检测克百威在土壤中的残留量.[结果]采用乙腈提取土壤中的克百威,氨基固相萃取小柱净化,高效液相色谱柱后衍生荧光检测器检测,方法回收率为89.1％～106.4％,相对标准偏差为1.5％～4.3％,最低检出限为0.01 mg/kg,符合农药残留分析要求.[结论]克百威在土壤中的半衰期为13.72～28.29 d,自然土壤法测得克百威对蚯蚓第7、14天的LC50值分别为9.856、8.778 mg/kg.     

反相高效液相色谱法测定嘧螨胺的含量

[目的]建立了反相高效液相色谱法测定嘧螨胺的方法.[方法]采用反相C18烷基柱,以乙腈-水(体积比80:20)为流动相,柱温为30℃,流速为1.0 mL/min,采用UVD紫外检测器在254 nm处进行检测.[结果]方法峰面积与质量浓度的线性关系良好,平均回收率99.9％,标准偏差为0.13.[结论]该方法简便、快速、分离效果好、精密度和准确度高、线性关系好.     

苯醚甲环唑水乳剂高效液相色谱分析

[目的]建立高效液相色谱法测定苯醚甲环唑水乳剂中苯醚甲环唑的含量的方法.[方法]分析条件:色谱柱Waters C18 Bondapak 300 mm×4.9 mm;以乙腈-甲醇-水(体积比45:40:15)为流动相;检测波长254 nm;流速0.7 mL/min.[结果]变异系数0.60%,标准偏差为0.061,平均回收率为99.3%.[结论]该方法具有较高的准确度和精密度,并且操作简便、快速,可用于产品质量分析检测.     

高效液相色谱串联质谱法分析水和饮料中13种常见农药

[目的]建立利用液相色谱串联质谱法检测水和6种饮料中13种常见农药的分析方法.[方法]空白检材加入内标和13种农药混标后用乙腈提取,离心后取上清液直接进样分析.液相色谱采用C18色谱柱,流动相用含甲酸铵和甲酸的水、乙腈梯度洗脱,质谱采用电喷雾离子源(ESI),正离子多反应监测(MRM)模式扫描.[结果]13种农药的检测限为0.1～50 μg/L;日内及日间精密度均在15％以下.[结论]方法简便、快速、灵敏、选择性高,可应用于实际案例的分析.     

离子色谱法测定草铵膦含量

[目的]建立草铵膦原药和草铵膦水剂的离子色谱定量分析方法.[方法]采用8 mol/L氢氧化钾水溶液为流动相,AS-11离子色谱柱(含AG-11保护柱)以及电导检测器对其有效成分草铵膦进行外标法定量分析.[结果]方法线性相关系数为0.9995(50～250 mg/L),标准偏差均小于0.08,变异系数均小于0.15％,平均回收率为100.26％.[结论]该方法可用于测定草铵膦原药或草铵膦水剂中的有效成分,具有精密、准确、简便易行的特点.     

超高压液相色谱-串联质谱法测定含硫蔬菜中烟碱类农药残留

[目的]为快速准确测定复杂基质样品中烟碱类农药残留,建立了含硫蔬菜中烯啶虫胺等烟碱类农药多残留的液相色谱-电喷雾串联质谱测定方法.[方法]样品经乙腈提取,用PSA、C18填料净化后,以BEH C18超高效液相色谱柱,以电喷雾离子源正离子多反应监测模式下进行测定.[结果]烯啶虫胺等7种农药在10-500 μg/L的范围内均成线性,回收率范围在70%～120%之间,方法的检出限在0.2～2.5 μg/kg之间.[结论]方法具有操作简便、重现性好和灵敏度高的特点,可满足含硫蔬菜中烟碱类农药残留限量检测的需要.     

高效液相色谱法分析15％炔草酯可湿性粉剂的含量

[目的]建立15％炔草酯可湿性粉剂的高效液相色谱分析方法.[方法]以乙腈-0.5％H3PO4水溶液(体积比60∶40)为流动相,使用Intersil ODS-3色谱柱,在波长为305 nm下,对15％炔草酯可湿性粉剂样品进行分析.[结果]方法的线性相关系数为0.9997,RSD为0.36％,在样品中的添加回收率为99.9％.[结论]该方法简便,重复性好,可以用于15％炔草酯可湿性粉剂的质量控制.     

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。