胶束增敏双硫腙分光光度法测定痕量铅

用异丙醇作溶剂溶解双硫腙,Tween-20作为增溶剂,在盐酸介质中,双硫腙水相直接光度法测定水中痕量铅。铅与双硫腙配合物的最大吸收波长为480nm,铅离子在0～150μg/L浓度范围内呈线性,相关系数r=0.9962,回收率为99.4%～101.4%。     

催化动力学分光光度法测定微量的汞

在pH=4.0的乙酸-乙酸钠缓冲溶液中,微量的Hg(Ⅱ)对亚铁氰化钾与1,10邻-菲啰啉(1,10-0-phen)显色反应有催化作用,加入硫脲能提高其灵敏度,显色程度与Hg(Ⅱ)量在一定范围内呈线性相关,借此建立测定微量Hg(Ⅱ)的分光光度法。实验表明,有色溶液最大吸收波长为515 nm,摩尔吸光系数ε=3.72×106L/(mo.lcm),相关系数为r=0.999 1,催化程度与Hg(Ⅱ)浓度在(0.0~1.2)μg/25 mL范围内符合比耳定律,选择性好,利用该方法直接测定人工合成水样中汞的含量,以及河水、池塘水中微量汞的含量分析,结果满意。     

胶束增溶分光光度法测定水溶液中的汞

研究了Hg(Ⅱ)-双硫腙(H2Dz)-十二烷基磺酸钠三元络合物显色体系,该体系的最大优点是可在水相中直接用光度法测定水样品中的汞含量.络合物的最大吸收波长490 nm,ε490=7.0×104L(mol·cm)-1,汞浓度在0.5～2.3 μg·mL-1范围内符合比尔定律.对样品进行回收实验,得到了很好的效果.     

高灵敏度显色反应测定水中痕量汞的研究

探讨水中汞的分光光度测定方法.在β-环糊精和曲拉通X-100存在下,基于汞与2-(5-溴吡啶-2-偶氮)-5-二乙氨基苯酚的显色反应,采用分光光度法进行测定.结果表明,配合物的最大吸收波长为565 nm,表观摩尔吸光系数为4.60×105L/(mol·cm),汞质量浓度在0～960μg/L范围内服从比尔定律,线性回归方程:A=0.002 3 c 0.007 1(c为汞的质量浓度,μg/L),相关系数r=0.998 4.本方法已用于水中痕量汞的测定,结果令人满意.     

高锰酸氧化苯酚红褪色光度法测定微量锰

在硫酸介质中 ,高锰酸氧化苯酚红褪色 ,由此建立了光度法测定微量锰的方法。锰含量在 0— 4 0μg/ 2 5m L范围内符合比耳定律。其表观摩尔吸光系数为ε=2 .0 4×10 4 。用于天然水中微量锰的测定 ,结果令人满意。     

新显色剂的合成及在环境样品中汞离子的检测研究

研究了十六烷基三甲基溴代铵(CTMAB)存在下汞离子与显色剂形成配合物从而进行分光光度法检测汞的最佳测试条件。汞离子与显色剂在波长405nm处有最大吸收,Hg2+的含量在1.5～100μg/25mL范围内符合朗伯比尔定律,表观摩尔吸光系数ε=0.191×105L·mol-1·cm-1,直线回归方程为:A=0.0039C-0.0029,相关系数为r=0.9984,摩尔比法测定配合物的组成比为n(Hg2+):n(显色剂)=1:2。     

罗丹明B光谱探针测定祛斑霜中微量汞

罗丹明B为光谱探针,研究了在三羟甲基氨基甲烷-HCl缓冲溶液(pH=6.5)中,十二烷基苯磺酸钠(SDBS)存在下,分光光度法测定祛斑霜中微量汞离子,得出了测定的优化条件.实验表明,室温下罗丹明B-SDBS-Hg2+形成水溶性三元复合物,最大吸收波长为554 nm,表观摩尔吸光系数ε=2.43×105L·mol-1·cm-1.Hg2+质量浓度在0～3.00μg/mL范围内服从朗伯-比尔定律.检出限为0.021μg/mL,加标回收率为98.5%～100.3%,RSD为1.06%～1.11%.     

二苯碳酰二肼分光光度法测定水样中的汞

以硼砂-氢氧化钠作为缓冲溶液,在溴化十六烷基三甲胺(CTMAB)及OP乳化剂存在下,Hg2+与过量二苯碳酰二肼(DPC)反应生成稳定的络合物,据此建立了二苯碳酰二肼光度法测定微量汞的方法。最大吸收波长为550 nm,表观摩尔吸光系数(ε550)为9.70×104L·mol-1·cm-1,Hg2+含量为0~1.4μg/mL范围内符合比尔定律,检出限为14.1μg·L-1。方法相对标准偏差(RSD,n=5)为1.1%~2.0%,回收率为98.6%~101.6%。采用本法,测定了污水及实验室废水中的微量汞,结果满意。     

氯化银比浊法测定炉水中的微量氯离子

用硝酸调节炉水的酸度,氯离子与硝酸银反应生成氯化银沉淀,用氯化银分光光度法,测定炉水中的微量氯离子。测定波长为410nm,线性范围15～2200μg/L。结果表明：其吸光值的大小与氯离子生成沉淀的多少成正比,符合朗伯一比尔定律。该法准确、快速、简便、安全,其它的常见离子无干扰。     

薄层树脂相吸光光度法同时测定痕量Fe(Ⅲ)和Fe(Ⅱ)的研究

Fe(Ⅲ)和Fe(Ⅱ)能在弱酸性条件下与邻菲啉(phen)生成稳定有色配合物[Fe(phen)]3 和[Fe(phen)]2 。该配合物能与阳离子交换树脂定量交换缔合,形成树脂(R-)-Fe(Ⅲ)-phen或(R-)-Fe(Ⅱ)-phen三元配位缔合体系。Fe(Ⅱ)表观摩尔吸光系数εF51e(2Ⅱ)=1.03×105L.mol-1.cm-1,比水相光度法提高21倍;测定Fe(Ⅱ)线性范围0~8.0μg/mL。400nm处Fe(Ⅲ)表观摩尔吸光系数4Fε0e(0Ⅲ)=2.6×104L.mol-1.cm-1,比水相光度法提高12倍;Fe(Ⅲ)测定线性范围0~12μg/mL。512nm处测定4.0μg Fe(Ⅱ)6次,RSD=1.37%;400nm处测定4.0μg Fe(Ⅲ)6次,RSD=2.74%。实测了天然水中Fe(Ⅲ)和Fe(Ⅱ)含量,并与AAS法测定结果比较,结果令人满意。     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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。     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.