反相高效液相色谱法测定甲锭反应液中甲锭含量

用反向高效液相色谱方法建立了甲锭的分析检测方法,并分离了甲锭及其衍生物.以甲醇:水=40:60为流动相,流量0.12 mL/min,在Therrno Hypersil ODS柱(2.1x100mm,3um),检测波长276 nn的色谱条件下,甲锭及其衍生物得到了很好的分离.在选用色谱条件下,甲锭在0.5ug/mL～10ug/mL检测范围内有良好的线性关系(R2=0.9998).通过该方法的精密度考察,在O.5ug/mL,2.5ug/mL和10ug/mL三个甲锭浓度,其相对标准偏差分别为1.311%、1.780%和0.861%.通过加标试验,甲锭在1ug/mL和10ug/mL两个浓度的相对标准偏差分别为2.717%和1.818%.     

反相高效液相色谱法分析甲锭反应液中甲锭含量

用反向高效液相色谱方法建立了甲锭的分析检测方法,并分离了甲锭及其衍生物.以甲醇:水=40:60为流动相,流量0.12 mL·min-1,在Thermo-Hypersil ODS柱(2.1mm100 mm,3 tan),检测波长276 nm的色谱条件下,甲锭及其衍生物得到了很好的分离.在选用的色谱条件下,甲锭在0.5～10 nlg·mL-1检测范围内有良好的线性关系(R2=0.9998).在0.5 nag·mL-1、2.5 mg·mL-1和10 nag·mL-13个甲锭浓度,其相对标准偏差分别为1.311%、1.780%和0.861%.通过加标试验,甲锭在1 mg·mL-1和10 mg·mL-1两个浓度的相对标准偏差分别为2.717%和1.818%.本法操作简便、快速、准确,可适用于甲锭化合物的定性与定量研究.     

4,4′-二苯甲烷二胺与碳酸二甲酯合成4,4′-二苯甲烷二氨基甲酸甲酯

研究了无水乙酸锌〔Zn(CH3COO)2〕催化下4,4′-二苯甲烷二胺(MDA)与碳酸二甲酯(DMC)合成4,4′-二苯甲烷二氨基甲酸甲酯(MDC)的反应。用高效液相色谱/质谱/质谱联用仪对反应体系副产物进行了检测分析。结果表明,MDC生成的适宜工艺条件为:催化剂用量n〔Zn(CH3COO)2〕∶n(MDA)=5∶1,反应物配比n(DMC)∶n(MDA)=20∶1,反应温度180℃,反应时间2 h。在该条件下MDC收率为98%,MDA转化率100%。分析结果表明,主要副产物为单氨基甲酸酯和3种N-甲基化物。在上述基础上,讨论了N-甲基化物可能的生成机制和副产物的形成对MDC生成的影响。     

4,4′-二苯甲烷二胺与碳酸二甲酯甲基化反应合成4,4′-双(二甲氨基)二苯甲烷

该文以4,4′-二苯甲烷二胺(MDA)与碳酸二甲酯(DMC)为原料合成4,4′-双(二甲氨基)二苯甲烷(MBDMA)。用不同类型催化剂对反应过程中甲氧羰基化和甲基化反应进行了调控。NaY分子筛催化剂促进甲基化反应的发生,适宜的反应条件为:催化剂用量m(NaY)∶m(DMC)=0.07∶1,反应物配比n(DMC)∶n(MDA)=30∶1,反应温度190℃,反应时间6 h,此时MDA完全转化,MBDMA选择性达97%。相反,乙酸锌催化剂则促进甲氧羰基化反应的进行。用高效液相色谱/质谱联用技术(HPLC/MS)对NaY催化下反应副产物的结构进行了分析,发现生成的副产物主要为3种不同程度的N-甲基化产物,表明MBDMA生成是经过逐步甲基化完成的。     

纳迪克酸酐的合成研究

以C5馏分中的环戊二烯为二烯体,顺丁烯二酸酐为亲二烯体,进行Dails-elder反应合成纳迪克酸酐,得到一种较好的外型纳迪克酸酐合成方法。并利用气相色谱-质谱联用法测定产物中外型产物的比率。通过正交试验对原料配比、滴加温度、滴加时间、反应温度、反应时间进行优化,得到最佳工艺条件:n(MA)∶n(CPD)=1.1∶1,滴加时间为4 0 min,滴加温度为2 5℃,反应时间为9 0 min,反应温度为3 5℃,此条件下合成产物的收率为84.79%,外式比例为49.21%。产物采用红外光谱进行了分析。     

稳定同位素标记妥布特罗-D9的合成

以自制的叔丁胺-D9为同位素标记前体,以邻氯苯乙酮为起始原料,溴化后,再与叔丁胺-D9经胺化、硼氢化钠还原后得到稳定同位素标记布特罗-D9。采用均匀设计对胺化步骤进行研究,实验数据通过多元回归分析,得出了优化的工艺条件:反应温度59℃,反应时间5 h,三氯甲烷为25 m L,n(溴代酮)∶n(叔丁胺-D9)=1∶2。目标产物结构经质谱(MS)、核磁(NMR)、高效液相色谱(HPLC)表征,产物纯度高于98.0%,同位素丰度高于97.5%(atom D),可作为食品安全领域检测用同位素内标试剂。     

双对甲氧基水杨醛缩二胺Schiff碱合成的研究

以间苯二酚为初始原料,通过甲酰化和甲基化制得对甲氧基水杨醛,再与二胺反应得到最终产物双对甲氧基水杨醛缩二胺Schiff碱,考察了反应条件对总收率的影响。结果表明,影响目标产物收率的主要是甲基化反应过程,并对其反应条件进行探索分析,得到最佳的甲基化条件为:加入少量K2CO3和Na OH,搅拌回流30 min,再慢慢滴加适量硫酸二甲酯,搅拌状态下回流5 h。在此条件下,产物为淡白色固体,收率可达75.5%。     

双对甲氧基水杨醛缩二胺Schiff碱合成的研究

以间苯二酚为初始原料,通过甲酰化和甲基化制得对甲氧基水杨醛,再与二胺反应得到最终产物双对甲氧基水杨醛缩二胺Schiff碱,考察了反应条件对总收率的影响。结果表明,影响目标产物收率的主要是甲基化反应过程,并对其反应条件进行探索分析,得到最佳的甲基化条件为:加入少量K2CO3和Na OH,搅拌回流30 min,再慢慢滴加适量硫酸二甲酯,搅拌状态下回流5 h。在此条件下,产物为淡白色固体,收率可达75.5%。     

甲醛法合成受阻胺光稳定剂

以受阻胺光稳定剂360为主要原料,以聚甲醛为甲基化试剂,以甲苯为溶剂,通过甲基化反应合成了受阻胺光稳定剂625,产物结构经~1HNMR进行了确证。通过单因素及正交实验,确定了适宜的甲基化反应条件为n(360)∶n(甲醛)=1∶4.6,反应温度85℃,反应时间6 h。在此条件下,甲基化率为97.4%。与甲醛/甲酸法相比,该反应过程无需加入甲酸,避免了光稳定剂360与甲酸成盐结块及繁琐的后处理过程,简化了操作,降低了成本,具有甲基化率较高和产物颜色较浅等优点。     

酸性离子液体催化合成三羟甲基丙烷三辛酸酯

以三羟甲基丙烷和正辛酸为原料,酸性离子液体为催化剂,制备了三羟甲基丙烷三辛酸酯。考察了反应物料投料比、反应时间、催化剂用量等因素对反应的影响。得到最佳反应条件:酸醇摩尔比4.2∶1,催化剂用量为三羟甲基丙烷和脂肪酸总质量的9%,反应温度为140℃,加热回流2 h,在该条件下,三酯收率98%,产品色泽浅。反应结束后离子液体与产物可分相。反应物与催化剂易分离,离子液体重复使用5次,催化活性没有明显下降。目标产物用红外光谱、液相色谱质谱联用仪、高效液相色谱、核磁共振波谱进行了表征和分析。     

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.     

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。     

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.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。