溴苯腈辛酸酯乳油的气相色谱分析

本文以ＯＶ－１０１０ 固定液，正二十二烷为内标物，气相色谱法测定溴苯腈辛酸酯乳油中有效成分含量。其标准偏差为０．１４，变异系数为０．５％，回收率为１００．５％。     

异丙甲草胺的气相色谱分析

本敢相色谱法分析异丙甲草胺的含量，选用ＳＥ－３０固定液，ＣｈｒｏｍｓｏｒｂＷ－ＡＷＤＭＣＳ为担体制备色谱柱，以正二十一烷为内标物，方法的标准偏差为０．１４％，变异系数为０．２０％，异丙甲草胺的回收率在９９．１６－１００．８０％之间。     

苄嘧黄隆分析方法研究

以甲萘威为内标物，用液相色谱分析嘧黄隆的含量，十次测定结果，其平均值为９０．０１％，标准偏差为０．３１％，变异系数为０．３３％，方法回收率为９９．２～１０１．０％。     

反相高效液相色谱法测定快杀稗

选用反相高效液相色谱法，在Ｃ１８反相柱上，以甲醇／ｐＨ３．０水为流动相，以邻苯二甲酸二乙酯为内标物，对快杀稗进行定量分析，９次测定结果，其平均值为８８．７４％，相对偏差为０．３７％，变异系数为０．６３％，平均回收率为９９．１％－１０１．９％，线性相关系数为０．９９９９７。     

嘧磺隆的高效液相色谱分析

采用高效液相色谱法，以Ｃ１８柱为分离柱，以甲醇－水－乙酸含０．０１ｍｏｌ．ｌ＾－１醋酸铵为流动相，内标法测定嘧磺隆的含是，９次测定结果，其平均值为８９．１４％，标准偏差为０．３９％，变异系数为０．５４％，回收率为９９．６％－１０１．４％。     

嘧磺隆的高效液相色谱分析

采用高效液相色谱法，以Ｃ１８柱为分离柱，以甲醇－水－乙酸（６０／４０／０．５）含０．０１ｍｏｌ·１－１醋酸铵为流动相，内标法测定嘧磺隆的含量，９次测定结果，其平均值为８９．１４％，标准偏差为０．３９％，变异系数为０．５４％，回收率为９９．６％～１０１．４％。     

丁草胺,恶草酮复配制剂的气相色谱分析

介绍了除草剂丁草胺和恶草酮复配制剂的气相色谱分析方法。选用１０％ＱＦ－１／Ｃｈｒｏｍｓｏｒｂ ＷＡＷ ＤＭＣＳ色谱柱，以邻苯二甲酸二甲酯为内标物，进行定量分析测定。丁草胺和恶草酮的线性回归系数分别为０．９９９５和０．９９９８，方法回收率在９８．８％￣１００．７％之间，标准偏差小于０．１４，变异系数优于０．７０％。     

氯氟乙禾灵高效液相色谱分析

本文选用高效液相色谱法，以二苯酮为内标物，对１２．５％氯氟乙禾灵乳油进行定量分析。本方法的变异系数为０．３７％，回收率平均值为９９．７１％，线性相关系数为０．９９９８。     

用高效液相色谱法测定氯嘧黄隆

选用反相高效液相色谱法，以β－萘酚为内标物，对氯嘧黄隆进行定量分析。本文法的变异系数为０．７１％，回收率为９８．９％￣１０１．７％，线性相关系数为０．９９９９。     

高效液相色谱法测定混配除草剂中苄嘧黄隆和乙草胺含量

采用Ｎｏｖａ－Ｐａｒｋ Ｃ１８柱进行反相高效液相层析，以内标法定量，测定了混配除草剂可湿性粉剂中苄嘧黄隆和乙草胺的含量。结果表明：各有效成分与内标物色谱峰分离完全，杂质无干扰。６次重复测定苄嘧黄隆和乙草胺含量的标准差分别为１．１８％和２．１０％，变异系数分别为０．５９６％和０．２１１％。     

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.     

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.     

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。