气相色谱测定柑橘中多种甲氧基丙烯酸酯类杀菌剂的残留量

[目的]建立一种同时测定柑橘中醚菌酯、唑菌胺酯、肟菌酯和烯肟菌酯残留量的气相色谱方法.[方法]柑橘中的杀菌剂经乙腈提取,盐析,固相萃取小柱净化,采用气相色谱电子捕获检测器进行分离和测定,外标法定量.[结果]醚菌酯、肟菌酯、唑菌胺醇和烯肟菌酯检测限分别为5、5、10、10μg/kg·在方法的检测限与2000g/kg范围内,线性相关系数大于0.9993,在所添加3个质量浓度水平下,方法的回收率为75％～95％,变异系数为4.0％～6.0％.[结论]该方法简便、准确、重现性好.     

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.     

苯醚菌酯(ZJ0712)的高效液相色谱分析

[目的]有关新颖杀菌剂苯醚菌酯的高效液相色谱分析,未见公开报道.建立了苯醚菌酯的高效液相色谱分析方法.[方法]采用高效液相色谱法,使用C18色谱柱和紫外检测器,以甲醇和水溶液(体积比70∶30)为流动相,流速为1.0 mL/min,在240 nm检测器波长下,对苯醚菌酯进行定量测定.[结果]苯醚菌酯标准偏差为0.144,变异系数为0.146％,平均回收率为99.59％,线性关系为0.9999.[结论]方法具有简便、快速、精密度和准确度高、线性关系好的优点,是较理想的分析方法.     

75%肟菌酯·戊唑醇WG高效液相色谱分析方法

[目的]建立一种利用HPLC测定75%肟菌酯·戊唑醇WG中有效成分的分析方法。[方法]采用Zorbax EcLipse XDB-C18不锈钢柱,以乙腈-水(体积比60∶40)为流动相,在波长220 nm条件下测定试样中肟菌酯和戊唑醇的含量。[结果 ]戊唑醇和肟菌酯的线性相关系数均为0.9999,标准偏差分别为0.093和0.109,变异系数分别为0.19%和0.43%,方法的平均回收率分别为100.17%和100.37%。[结论]该方法具有操作简便、分离效果好、线性关系良好、准确度和精密度高等优点,适用于制剂中肟菌酯和戊唑醇的定量分析。     

30%啶酰菌胺·肟菌酯悬浮剂的高效液相色谱分析

[目的]建立一种用高效液相色谱法同时测定啶酰菌胺和肟菌酯含量的分析方法。[方法]采用ZORBAX SB-C18色谱柱分离,以甲醇和水(体积比75∶25)为流动相,流速1.0 mL/min,柱温25℃,波长254 nm下同时定量测定20%啶酰菌胺10%肟菌酯悬浮剂含量。[结果]在优化的色谱条件下,啶酰菌胺的色谱保留时间为3.946 min,肟菌酯的保留时间为9.446 min;二者的线性相关系数分别为0.999 9、0.999 9,方法的标准偏差分别为0.094、0.068,变异系数分别为0.46%、0.68%,平均回收率分别为99.41%、99.81%。[结论]此方法分析快速,所得的结果可信度高,是较理想的分析方法。     

肟菌酯和戊唑醇在马铃薯种植体系中的沉积和降解行为

[目的]系统评价戊唑醇和肟菌酯及其代谢产物肟菌酸在马铃薯种植体系中的沉积、降解、累积等残留行为.[方法]建立了超高效液相色谱-串联质谱(UPLC-MS/MS)残留分析方法,通过残留田间试验,对不同剂量条件下马铃薯植株和块茎中肟菌酯、肟菌酸和戊唑醇的残留量进行了测定.[结果]在0.02～20.0 mg/kg的添加水平下,...     

水杨腈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水杨腈的定量分析方法.[方法]采用C18色谱柱,以乙腈-水(体积比48∶52)为流动相,流量为0.5 mL/min,柱温为30℃,选择230 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0.20,平均回收率为99.8％.[结论]方法具有简便、快速、分离效果好、精密度和准确度高、线性关系好的特点.     

24.1%异噻菌胺·肟菌酯悬浮种衣剂高效液相色谱分析

[目的]建立高效液相色谱同时检测异噻菌胺、肟菌酯的分析方法。[方法]以乙腈-磷酸溶液为流动相,使用ZORBAX SB-C18、5滋m为填料的不锈钢柱和光电二极管阵列检测器,在254 nm波长下对24.1%异噻菌胺·肟菌酯悬浮种衣剂进行分离和定量分析。[结果]该方法检测异噻菌胺、肟菌酯的线性相关系数分别为0.999 6、0.999 1;标准偏差分别为0.15、0.02,变异系数分别为0.88%、0.37%,平均回收率分别为99.96%、99.91%。[结论]分析方法具有操作简便、快速,分离效果好、准确度和精确度高、线性关系好的特点。     

40%肟菌酯·咪鲜胺水乳剂高效液相色谱分析

[目的]建立液相色谱法测定40%肟菌酯·咪鲜胺水乳剂的定量分析方法。[方法]以甲醇-乙腈-水(体积比为31:38:31)为流动相，使用C18色谱柱，流量为0.9 mL/min，柱温为25℃，选择230 nm波长检测。[结果]咪鲜胺和肟菌酯的相关系数分别为0.9996和0.9991，相对标准偏差均为0.3%，样品平均回收率分别为100.3%和99.79%。[结论]此方法快捷简便易操作，准确度和精密度高，线性关系良好。     

丙硫菌唑和肟菌酯混剂产品高效液相色谱分析方法

建立一种可以同时检测丙硫菌唑和肟菌酯混剂中2种有效成分的高效液相色谱法,为产品质量控制提供技术支持.以甲醇-0.1％磷酸水溶液(体积比70:30)为流动相,采用流动相溶解试样,选取XDB-C18为填充物的不锈钢色谱柱和紫外检测器,在254 nm紫外波长下,对样品中丙硫菌唑和肟菌唑进行分离和定量分析.采用HPLC-DAD...     

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。