AHMT分光光度法测定废水中微量甲醛

甲醛与4-氨基-3-联氨-5-巯基-1,2,4-三氮杂茂(简称AHMT)溶液在碱性条件下缩合,然后经高碘酸钾氧化成6-巯基-5-三氮杂茂(4,3-b)-S-四氮杂苯紫红色化合物,其颜色的深浅与甲醛含量成正比。方法的最大吸收波长为554nm,甲醛含量在0~12μg·10mL-1范围内具有良好的线性关系,相关系数为0.9959,用于测定有机实验废水中微量甲醛的含量,相对标准偏差为3.45%,加标回收率在95.4%~110.5%之间。     

6-巯基-5-三氮杂茂[4,3-b]-S-四氮杂苯的合成及在甲醛残留快速检测中的应用

采用4-氨基-3-联氨-5-巯基-1,2,4-三氮杂茂为原料合成6-巯基-5-三氮杂茂[4,3-b]-S-四氮杂苯,并配成0至1000mg/L标准色列。采用三氮杂茂快速检测方法测定食品中甲醛含量,用乙酰丙酮比色检测方法对三氮杂茂快速检测方法的检测结果进行验证,符合率在64%~95%。     

AHMT分光光度法检测甲醛浓度的影响因素

AHMT分光光度法是检测室内空气中甲醛浓度的常用方法。首先,4-氨基-3-联氮-5-琉基-1,2,4-三氮杂茂(AHMT)在碱性条件下与甲醛进行缩合反应;然后用KIO_3将反应产物氧化成紫红色化合物;最后通过体系的吸光度来计算定量甲醛的浓度。本文研究分析了显色剂用量、氧化时间、KOH的浓度、氧化剂用量、显色反应温度等因素对检测结果所造成的影响,并通过分析结果确定AHMT分光光度法的最佳实验条件。     

双(1,3-二叠氮基-2-丙基)缩甲醛的合成及表征

以1,3-二氯-2-丙醇、聚甲醛等为原料,在催化剂作用下通过缩合反应,制得中间体双(1,3-二氯-2-丙基)缩甲醛(BCPF),进而在极性溶剂中与金属叠氮化物反应,得到目标产物双(1,3-二叠氮基-2-丙基)缩甲醛(BDPF),产率98%,纯度98%;用红外、核磁共振、元素分析等方法对其结构进行表征.考察了催化剂、反应温度、反应介质对反应的影响并得出最佳反应条件:缩合反应温度为0～5℃,催化剂浓硫酸用量4mL,1,2-二氯乙烷为反应介质;叠氮化反应温度95～99℃,溶剂为二甲基亚砜,反应时间4h.     

EGF受体配基N2S2-Quinazoline的合成

以6-硝基喹唑啉酮为原料,经过氯化亚砜氯化,间碘苯胺连接,氯化亚锡还原,制得6-氨基-4-[(3-碘苯基)氨基]-喹唑啉,再与氯乙酰氯反应,二硫二氮缩合连接,最后与醋酸汞硫化氢反应脱巯基保护基得到标记前体N-[[4-(3-碘苯基)氨基]-喹唑啉-6-基]-2-[N-(2-巯基乙基)-N-[[N-(2-巯基乙基)氨基]甲酰甲基]]乙酰胺,主要产物得到核磁和质谱表征,总收率2.5%。     

(6R,7R)-苯甲酰氨基-3-(1-甲基-5-四氮唑)-硫甲基-7-甲氧基-8-氧代-5-氧杂-1-氮杂二环[4.2.0]辛-2-烯-2-羧酸二苯甲酯的合成

以氧头孢烯为起始原料,通过甲氧基化得到甲氧基氧头孢烯,再在磺酰氯和三乙胺催化作用下与1-甲基-5-巯基四氮唑反应,得到(6R,7R)-苯甲酰氨基-3-(1-甲基-5-四氮唑)-硫甲基-7-甲氧基-8-氧代-5-氧杂-1-氮杂二环[4.2.0]辛-2-烯-2-羧酸二苯甲酯,总收率约78%,产物结构经核磁,质谱数据表征确认。     

达村斯(Darzens)缩合反应的研究与应用进展

简单介绍了Darzens缩合反应,综述了α-卤代腈、α-卤代酮、α-卤代砜、α-卤代酯、α-卤代酰胺等与醛、酮的Darzens缩合反应以及氮杂Darzens缩合反应,对Darzens缩合反应的应用进行了总结和展望。指出应加强对Darzens缩合反应的系统研究,特别是对手性催化Darzens缩合反应及氮杂Darzens缩合反应的研究。     

2,2-二羟甲基丁酸合成工艺研究

以正丁醛、甲醛和双氧水为主要原料,经羟醛缩合、氧化反应制备2,2-二羟甲基丁酸,考察了缩合、氧化反应条件。结果表明,最佳缩合反应条件为:正丁醛∶甲醛∶双氧水=1∶2.4∶1.4(摩尔比),缩合反应温度35℃左右,缩合反应时间6 h;氧化反应条件为:温度80℃左右,反应时间6 h。反应液采用离子交换→真空浓缩→溶剂结晶→重结晶工艺处理,2,2-二羟甲基丁酸产品总收率大于40%。     

具有优良的抗焦烧性能与耐热老化性能的氯丁橡胶的配方研究

6-R-1,3,5-三氮杂苯-2,4-二硫醇(I)的锌盐是TW型氯丁胶的有效交联剂,可用以制得抗焦烧性能优良的混炼胶和耐热老化性能卓越的硫化胶。此外,在W型氯丁胶中,以Ⅰ的锌盐和促进剂DM并用,能制得具有同样特征的橡胶材料。典型的配方(重量份)分别为:6-苯胺基-1,3,5-三氮杂苯-2,4-二硫醇(AF)的锌盐10,ZnO 5,MgO 4;AF的锌盐1.5,DM 1.0,ZnO 5,MgO 4。I的锌盐和DM并用时的交联反应估计同时包含了两个反应,即:(1)由锌盐生成(I),而取代氯丁胶中活性氯的取代反应;(2)由(I)与DM生成的6-R-1,3,5-三氮杂苯-2,4-双(苯并噻唑-2-二硫化物)分解,生成二硫代三氮杂苯自由基而引发的交联反应。反应的结果主要生成二硫代三氮杂苯交联键。     

三种分光光度法测定水中甲醛的对比分析与方法评价

对现行实施的测定水中甲醛的三种分光光度标准分析方法,进行了比对分析试验;并从方法学的角度进行方法评价。测定水中甲醛的标准分析方法,主要有《4-氨基-3-联氨-5-巯基-1,2,4-三氮杂茂(AHMT)分光光度法》、《乙酰丙酮分光光度法》和《变色酸分光光度法》。对这几种分析方法,在实际分析测定的基础上,分别从方法的校准曲线、试剂空白影响、方法的灵敏度、有效测定范围等方面进行比对分析和评价。结果表明,在上述几种分析方法中,AHMT分光光度法的灵敏度最高,分别比变色酸光度法和乙酰丙酮光度法高1倍和4倍;同时方法的选择性好,可使大量醛类共存下不干扰测定,是现行标准分析方法中的优选分析方法。     

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。