PVC盐酸氨溴索选择性电极的制备

以四苯硼酸氨溴索离子缔合物做电活性材料,制成氨溴索PVC电极,对影响电极性能的诸因素作了研究,以最佳条件制备的电极线性范围为1.0×10~(-2)～9.0×10~(-6)mol/L,平均斜率为56.2 mV/decade,检测下限为4.5×10~(-6)mol/L,在PH<5.0的范围内适用,电极响应快,重现性和稳定性好,抗干扰能力强,适用于氨溴索样品的快速测定。     

一种新的全固态Zn（CN）4^2—电极用于镀锌液中锌的测定

本文报道了一种新的全固态Zn(CN)_4~(2-)离子电极的研制,以正交试验设计方法采用L_9(3~3)正交表试验优化电极性能。确定以十六烷基三丁基碘化铵(HTBA)为离子载体,膜含量5％,络合剂KCN浓度0.5mol/L时为最优因子组合。电极的平均斜率可达28.6mV/pc(20℃),线性范围1.0×10~(-1)～2.4×10~(-6)mol/L,检测下限4.0×10~(-7)mol/L。将电极用于各种镀锌液中Zn含量测定时,获得了良好的结果。     

1,1,1-三[1''''-(2''''-氧杂-4''''-氧代-5''''-氮杂-5''''-甲基)十二烷基]丙烷锂离子选择电极的研制

研究了各种增塑剂和添加剂对1,1,1-三[1′-(2′-氧杂-4′-氧代-5′-氮杂-5′-甲基)十二烷基]丙烷为中性载体的 PVC 膜锂电极性能的影响。结果表明,磷酸三酯类对锂有良好的选择性。以 TEHP为增塑剂的锂电极线性响应范围是4×10~(-5)～10~(-1)mol·dm~(-3)(LiCl)。选择系数 K(?)是5×10~(-2),K(?)是5×10~(-3),K(?)是7×10~(-5),K(?)是3×10~(-3)。适量添加剂 TOPO 的加入可使 K(?)略有减小。膜内加入少量的 TOPO、KTPB 或 LiClO_4能降低膜的内阻,但随着膜中 TOPO 和 KTPB 含量的增加,电极性能明显变差。     

C12-2-C12·2Br选择性膜电极的制备及性能

以四苯硼酸钠与季铵盐Gem in i表面活性剂(C12-2-C12.2B r)生成的沉淀物质作为电活性物质制备选择性膜(PVC)电极,在所考察的15~45℃内,膜电极对C12-2-C12.2B r水溶液的检测下限浓度为1.5×10-6mol.L-1,线性响应浓度为2.5×10-6~9.0×10-4mol.L-1,响应斜率为(30.0±2)mV/decade。电极适用于pH=6~12水溶液,其稳定性和重现性均良好。     

基于硫氮杂冠醚化合物为载体的汞离子选择性电极的制备与表征

制备了一种新的基于硫氮杂冠醚化合物为载体的汞离子选择性电极,电位响应表明该电极对汞离子有好的选择性.在考察增塑剂以及离子交换剂对电极响应性能的基础上,以最佳膜组分测得该电极的线性响应范围为1.O×10-6～1.0 × 10-4mol/L,响应斜率为29.6 ±0.1 mV/dec.,检出限为6.5×10-7 mol/L...     

一种新的PVC膜铜离子选择性电极的制备及应用

制备了以N,N'-二(N-异丙基-N-2-羟乙基)-1,3-苯二甲酰胺(L)为载体的PVC膜铜离子选择性电极,研究了电极膜中增塑剂种类及载体和离子定域体(KTpClPB)含量对电极性能的影响。结果表明:此电极对Cu2+具有很好的能斯特响应性能,在10-3~10-1mol/L的浓度范围内呈良好的线性关系,检测下限为2.86×10-4mol/L,电极响应斜率为(29.1±0.2)mV/decade。选择性上,碱金属、碱土金属及大多数过渡金属离子对Cu2+的测定基本无干扰。该电极用于废水中Cu2+含量的测定,并且能对实际样品中Cu2+含量的直接测定。     

离子电极用于煤基甲醇溶液中微量铬的测定

以3-甲氧基噻吩-2-甲醛和邻苯二胺合成的席夫3-甲氧基噻吩-2-甲醛缩-邻苯二胺为中性载体,将其与碳粉混合,以液体石蜡为粘合剂,制备了新型的铬(Ⅲ)离子选择性电极。室温下,电极对Cr~(3+)的能斯特响应范围为4.00×10~(-7)～1.00×10~(-2)mol/L,斜率为18.23mV/dec,检出限为3.02×10~(-7)mol/L。电极响应时间小于20s,pH使用范围广(3.30～5.00),稳定性好,使用寿命长。在选定的条件下,考察了10余种离子的干扰情况,并利用该离子选择性电极对煤基甲醇中的Cr~(3+)进行了测定,取得了较好结果。     

杯芳烃修饰主客体化学传感器研究--对甲酚的测定

以C-十-烷基间苯二酚杯(6)芳烃作为主体分子,修饰于玻碳电极上,制成的一种主客体化学传感器.并用其对溶液中的客体分子--对甲酚进行测定.该电极具有良好的选择性,对5.0×10-5～2.0×10-3mol·L-1的对甲酚具有很好的线性响应.检测下限为3.0×10-5mol·L-1.同时,对修饰前后玻碳电极的表面状态进行了研究.     

全固态硝酸根离子选择性电极的制备及其性能研究

硝酸盐含量常用于判断水体质量和受污染程度,是重要的水质检测指标。以玻碳电极为基底电极、聚3,4-乙烯二氧噻吩(PEDOT)为固态接触层、聚氯乙烯(PVC)为敏感基膜制备了一种新型全固态硝酸根离子选择性电极,并考察了该电极的电化学特性。结果表明,以PEDOT为固态接触层能有效促进电极离子—电子之间信号传导,提高电极的稳定性。该电极在1×10~(-1)～1×10~(-5)mol/L范围内的硝酸铵溶液中呈良好的能斯特响应,响应斜率可达53.7 m V/dec,响应时间在50 s以内。该电极的重现性、选择性好,使用寿命超过3个月。     

测定亚硝酸根的电位型漆酚树脂传感器研究

以漆酚树脂为新型载体 ,研制了对亚硝酸根 ( NO-2 )有选择性响应的传感器。该传感器灵敏度高 ,重现性好 ,选择性好 ,其线性范围 1.0× 10 -2 ～ 5 .0× 10 -6 mol L,检测下限 2 .2× 10 -6 mol L,斜率 5 9.1m V( 30℃ ,p H 7.6)。     

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。