精己二酸中金属杂质元素的分析

建立了精己二酸中金属杂质元素的分析方法。精己二酸用2%(V/V)的硝酸溶解后,采用电感耦合等离子体质谱(ICP-MS)法直接测定其中的Cr、Fe、As、Cd、Sb、Hg、Pb。针对样品溶液中的基质元素所形成的多原子离子干扰,采用八极杆碰撞/反应池(ORS)技术,向ORS中通入He气体。与无气体模式比较,利用氦碰撞模式消除干扰,明显降低了各元素的背景等效浓度和检出限。各元素仪器的检出限为0.86~32.5 ng·L-1。采用加标回收实验验证了方法的准确性,各元素的回收率在93.6%~107.6%之间。样品处理简单,方法完全能满足精己二酸中杂质元素的分析要求,可用于生产现场精己二酸的实时质量监测。     

ICP-AES法测定玻璃态偏磷酸铝中着色杂质元素研究

通过建立盐酸高压消解等离子体发射光谱法测定高纯玻璃态偏磷酸铝中杂质元素的方法,确定了高纯玻璃态偏磷酸铝中微量着色元素Fe、Cu、Cr、Co、Ni、Mn、V、Ti的检测条件,使各着色离子平均回收率为94.6%~110%,相对标准偏差RSD为0.6%~5%。本方法可准确、快速测定高纯玻璃态偏磷酸铝中着色杂质元素。     

ICP-AES法测定ITiO(铟钛靶材)中铁钙镁锡

建立了电感耦合等离子原子发射光谱法测定ITi O(铟钛靶材)粉末中Fe、Ca、Mg和Sn等杂质元素的分析方法。对溶液酸度、基体干扰、共存元素干扰等进行了试验和讨论,优化了仪器工作参数,方法的精密度(RSD,n=9)为0.41%~2.51%;回收率为99%~103%。适用于ITiO(铟钛靶材)粉末中杂质元素铁、钙、镁和锡量的测定。     

标准加入ICP-AES法测定金属镓中9种杂质元素

采用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定镓中的Cu、Pb、Zn、A l、In、Ca、Fe、Sn、Ni 9种杂质元素,并以差减法计算基体镓的含量,实现了对试样基体及杂质元素含量的同时测定。以标准加入法配制校准曲线,有效地消除基体干扰。结果表明该方法对9种杂质元素的回收率在89%~103.5%,相对标准偏差低于5.0%。方法简单、快速,测定结果满意。     

ICP-AES法测定Beta沸石中常量和微量组分

研究了沸石分子筛中主要和微量组分电感偶合等离子体发射光谱（ICP-AES）测定方法。考察了溶样酸度、仪器条件对测定的影响,以及共存元素间的干扰情况,优化了工作条件。实验结果表明,常量元素相对标准偏差（RSD）<1%,回收率为98.6%;杂质元素RSD<7%,回收率为85%~112.1%。     

ICP-MS法核级海绵锆中痕量杂质含量的测定

建立了一种核级海绵锆中20种杂质元素电感耦合等离子体质谱测定方法,通过加入内标元素Sc、Rh、Tm,有效地消除了测定中的基体效应,仪器的检出限为0.02~0.31 ng/m L,加标回收率为84%~110%,相对标准偏差RSD5%。该方法能够满足核级海绵锆中杂质的测定。     

ICP-OES测定铝合金中多元素的方法探索

探讨电感耦合等离子体发射光谱法(ICP-OES)同时测定铝合金中硅,铁,镁,铜,锰,铬和锌等七种元素的方法。通过选择各元素的最佳光谱线和优化工作条件,得出该方法快速,简便,分析周期短,符合生产要求。测定的元素含量范围为0.060%~0.779%。用该方法测定铝合金中的硅,铁,镁,铜,锰,铬和锌,相对标准偏差RSD为小于3%,回收率为96.2%~102%。     

电解分离-ICP-AES法测定硫酸铜中杂质元素

对硫酸铜水溶液直接进行电解,控制电解电流为3 A,电解30 min后将电解液用水稀释至100 m L并进行测定,建立电解分离-电感耦合等离子体发射光谱法(ICP-AES)测定硫酸铜中15种杂质元素(Al、Be、Ca、Cd、Co、Cr、Fe、Li、Mg、Mn、Ni、Si、Sr、V、Zn)的方法。测定各杂质元素的检出限在0.002~1.5 mg/kg之间。对硫酸铜样品中杂质元素平行测定并进行加标回收试验,各元素测定的相对标准偏差在0.62%~1.88%(RSD,n=6)之间,各元素平均加标回收率在92.22%~109.93%(n=6)之间。该方法操作简单、电解时间短,能有效去除样品溶液中的铜基体,大大降低了基体效应,具有良好的精密度和准确度,并可以对多种杂质元素同时测定。     

ICP-AES测定铜精矿中的汞和砷

本文以盐酸和硝酸在比色管中,在水浴环境下直接溶解样品,最大限度避免元素挥发损失和外界污染。电感耦合等离子体发射光谱仪,测定铜精矿中的有害杂质元素砷和汞。实验结果表明,汞回收率为98%~102%,砷的测定结果与国家标样值吻合。砷相对标准偏差(RSD)(N=11):0.65%,汞相对标准偏差(RSD)(n=11):1.28%。方法操作简单,分析快速,结果准确。     

微波消解-ICP-AES法测定电镀金层中的杂质元素含量

研究了微波消解-ICP-AES法测定电镀金层中Ag、Cd、Co、Cr、Cu、Fe、Ni、Pb、Sn、Zn元素质量分数的方法。采用微波消解法溶解样品,在分析条件下对各元素的多条分析谱线进行比较,选择线性最好、测量结果最稳定的分析谱线建立分析方法。实验结果表明,标准曲线的相关系数均0.999 9,对各杂质元素质量分数为0.05%的标准样品进行11次测量得到的RSD1.2%,杂质元素质量分数检出限0.001%,回收率在98.4%~101.5%之间。该方法简便、准确、灵敏、快速,并能同时进行多种元素测定等,适用于日常生产检测。     

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.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。