尿中4种麻黄素类药物的GC／MSD测定

麻黄素、伪麻黄素、去甲麻黄素、去甲伪麻黄素作为兴奋剂药物及相关化合物被国际奥委会规定为禁用药物~[1],并对其作了限量规定~[2].前文曾用气相色谱法对该类药物进行了分离与测定~[3].本文采用色质联用技术,对含有这4种药物的尿样进行了分离,并采用选择离子检测(SIM)方式,以二苯胺为内标准物建立了对这4种药物同时定量的测定方法.本方法最低检测限为1μg/mL尿.其它兴奋剂药物及尿中化合物对检测无干扰.     

双手性氨基醇水杨醛Schiff碱铜络合物构型与环丙烷化反应立体选择性的关系

利用去甲麻黄素及假去甲麻黄素为手性源，合成了３个水杨醛Ｓｃｈｉｆｆ碱铜（Ⅱ）络合物，并将其应用于烯烃与重氮乙酸乙酯的环丙烷比反应，结果表明：此类铜（Ⅱ）络合物催化环丙烷反应可得到光学异构体过量的产物，络合物中与氮相连的碳原子构型对产物的构型起决定作用，与氧相连的碳原子构型不起决定作用，但对手性诱导能力产生较大的影响；两个手性碳原子构型相异时对手性诱导能力起促进作用，相同时起削弱作用．     

双手性氨基醇水杨醛Schiff碱铜络合物构型与环丙烷化反应立体…

利用去甲麻黄素及假去甲麻黄素为手性源，合成了３个水杨醛Ｓｃｈｉｆｆ碱铜（Ⅱ）络合物，并将其地烯烃与重氮乙酸环丙烷化丙化反应，结果表明：此类铜（Ⅱ）络合物催化环丙烷反庆可得到光学异构体过量的产物，络合物中与氮相连的碳原子构型对产物的构型起决定作用，与氧相碳原子构型不起作用，但对手性诱导能力产生较大的影响；两个手性碳原子构型相异时对手性诱导能力起促进作用，相同进起削弱作用。     

示波极谱滴定法测定有机碱盐酸盐类药物

示波极谱滴定法测定有机碱盐酸盐类药物①战永复孟昭仁赵桂荣（吉林师范学院化学系，吉林１３２０１１）郑建斌高鸿（西北大学电化学分析研究所）盐酸苯海拉明是抗过敏药，盐酸普鲁卡因是局麻药，ＶＢ１与ＶＢ６是维生素类药物，盐酸麻黄素是平喘药，其测定方法文献报道...     

手性胶束中的不对称Micheal反主尖

本文研究了手性表面活性剂N,N-二甲基-N-十二烷基麻黄素溴化铵及N,N-二甲基-N-十六烷基麻黄素溴化铵所形成的手性胶束体系中,以六氢吡啶作为碱催化剂,硝基甲烷或硫酚对查耳酮类化合物的Michael加成反应.     

右旋肌醇甲醚唑类核苷类似物的合成

糖基部分中氧原子被亚甲基代替的碳环核苷是核苷类药物发展的一个重要方向.这类化合物表现出了比较宽的生物活性谱,特别是作为抗肿瘤[1]和抗病毒[2]药物的开发具有良好的前景.     

手性胶束中的有机反应(Ⅴ)——手性胶束中查耳酮的不对称环氧化

本文报道查耳酮用H₂O₂在手性表面活性剂N,N-二甲基-N-十二烷基麻黄素澳化铵(1a)及N,N-二甲基-N-十六烷基麻黄素溴化铵(1b)形成的手性胶柬水溶液中的不对称环氧化反应,得到相应的手性α,β-环氧酮,对映体过量为5～8%.     

乙酰化β-环糊精手性固定相拆分测定肾上腺素类对映体

1引言肾上腺素（EpinephrineE）和去甲肾上腺素（NorepinephrineNE）临床上用于支气管哮喘中毒性休克或心肌骤停等的治疗。由于药物对映体之间在药理、毒理和临床疗效等方面常存在较大差异,故拆分肾上腺素类对映体,建立简便而特异的药物对映体测定方法在药物及临床医学等领域中具有重要意义。本文首次采用乙酰化-β-环糊精手性固定相反相直接拆分肾上腺素类对映体,系统研究流动相组成等因素对分离效果的影响,优化了实验条件,使分析过程直接、快速、灵敏。可望用于肾上腺素类药物对映体的分离测定。2实验部分2．1仪器与试剂SHIMADZ…     

4β-氮取代氨基酸的5-Fu酯-4′-去甲表鬼臼的合成

根据药物设计中的结合原理,考虑到氨基酸具有较好的水溶性,并具有降低药物毒性的作用,我们以氨基酸为载体将抗肿瘤药物5-Fu和4′-去甲表鬼臼结合. 以N-保护的氨基酸钾盐与1-(ω-溴丙基)-5-Fu反应制备得到氨基酸的ω-(N1-5-Fu基)-丙醇酯,再与4β-Br-4′-去甲表鬼臼反应,制备了四种4β-氮取代氨基酸的ω-(N1-5-Fu)酯-4′-去甲表鬼臼.合成路线如下:     

手性胶束的不对称诱导作用不对称苯偶姻缩合反应

胶束体系是模拟酶的简单模型之一。手性胶束对反应有手性诱导作用。在表面活性剂(1R，2S)-(-)-N-十二烷基-N-甲基麻黄素溴化物和(1R，2S)-(-)-N-十六烷基-N-甲基麻黄素溴化物形成的胶束体系中进行的苯偶姻缩合反应，生成了光学活性的α-羟基酮。     

Dependence of the Rate of Electrodeposition of Metals at Mono- and Multielectrodes on Voltage in the Case of an Exaltation Mechanism of Mass Transport

Dependences of the rate of copper deposition on mono- and multielectrodes out of dilute solutions of acetic acid at voltages of 20–250 V are compared. It is established that the same rate of deposition in the case of a multielectrode (25 electrodes with a diameter of 0.1 mm) takes place at a voltage that is lower by 2.7 times than that in the case of a monoelectrode with a diameter of 0.5 mm and the same area. The same results are obtained during electrodeposition of cadmium and thallium. In order to explain this effect, a two-layered model of potential distribution is suggested. In accordance with this model, the resistance of electrolyte in the vicinity of a multielectrode is equal to the sum of the resistance of the layer nearest to the electrode (where it is determined by the sum of conductances to each microelectrode) and the external layer, where the potential distribution is close to hemispherical. It is shown that calculations in accordance with this model allow one to give an estimate of the effect's scale that agrees with experiment and to predict its possible limits following an increase in the number of electrodes that make up a multielectrode.     

渣油悬浮床加氢水溶性催化剂预硫化研究 Ⅱ 钼酸盐硫化产物的XPS分析

通过XPS分析法对钼酸盐的硫化行为进行了考察,分别考察了四价钼物种质量分数和硫钼元素的质量分数比，发现硫化产物的表面化学组成中四价钼质量分数和硫钼元素质量分数比不成正比，证实了该产物表面钼的硫化物不完全以MoS2形式存在。未经过临氢加热的硫化产物表面的四价钼物种的质量分数显著低于经过临氢加热的样品的质量分数，说明临氢加热在钼酸盐的硫化过程中起了重要作用。氯化铵是钼酸盐硫化过程中有效的助硫化剂，当它的用量增大时，硫化产物表面四价钼的质量分数也增大。以蒽为探针，使用化学探针法测定了硫化产物在渣油加氢过程中的催化活性，发现随着氯化铵用量的增加，产物的催化活性也相应提高，印证了XPS测定结果。     

Review of non-reactive and reactive wetting of liquids on surfaces

Wettability is a tendency for a liquid to spread on a solid substrate and is generally measured in terms of the angle (contact angle) between the tangent drawn at the triple point between the three phases (solid, liquid and vapour) and the substrate surface. A liquid spreading on a substrate with no reaction/absorption of the liquid by substrate material is known as non-reactive or inert wetting whereas the wetting process influenced by reaction between the spreading liquid and substrate material is known as reactive wetting. Young's equation gives the equilibrium contact angle in terms of interfacial tensions existing at the three-phase interface. The derivation of Young's equation is made under the assumptions of spreading of non-reactive liquid on an ideal (physically and chemically inert, smooth, homogeneous and rigid) solid, a condition that is rarely met in practical situations. Nevertheless Young's equation is the most fundamental starting point for understanding of the complex field of wetting. Reliable and reproducible measurements of contact angle from the experiments are important in order to analyze the wetting behaviour. Various methods have been developed over the years to evaluate wettability of a solid by a liquid. Among these, sessile drop and wetting balance techniques are versatile, popular and provide reliable data. Wetting is affected by large number of factors including liquid properties, substrate properties and system conditions. The effect of these factors on wettability is discussed. Thermodynamic treatment of wetting in inert systems is simple and based on free energy minimization where as that in reactive systems is quite complex. Surface energetics has to be considered while determining the driving force for spreading. Similar is the case of spreading kinetics. Inert systems follow definite flow pattern and in most cases a single function is sufficient to describe the whole kinetics. Theoretical models successfully describe the spreading in inert systems. However, it is difficult to determine the exact mechanism that controls the kinetics since reactive wetting is affected by a number of factors like interfacial reactions, diffusion of constituents, dissolution of the substrate, etc. The quantification of the effect of these interrelated factors on wettability would be useful to build a predictive model of wetting kinetics for reactive systems.     

Evaluation of Properties of Concrete Without Cement Produced Using Fly Ash-Based Geopolymer

The use of ordinary Portland cement (OPC) in the construction industry is inevitable. The huge production of OPC and its use in infrastructural development pose an environmental impact. Greenhouse gas emitted increases the global temperature and it is an alarming sign to everybody on the planet. Concrete is the most consuming material which is produced by using OPC and it is proven that OPC contributes a lot to CO₂ emission. Hence in this study attempt is made to produce concrete by using environment-friendly material like fly ash along with alkaline activators, which is termed Geo polymer concrete. The by-product fly ash is widely available worldwide. It is a by-product of thermal power plants. The use of fly ash in concrete produces less expensive and more cost-effective concrete than concrete made up using OPC. Due to its high silicate and alumina content, fly ash reacts with an alkaline solution to create an aluminosilicate gel that binds the aggregate and results in high-quality concrete. Fly ash is finer than cement, it occupies the pores of cement after hydration. This would result in denser concrete which gives higher strength. In comparison to ordinary concrete, fly ash-based geopolymer concrete offers better resistance to aggressive environments and high temperatures. In the present study, an alkaline activator of molarity 8 is used to prepare geopolymer concrete. The test specimens are cast and cured for 28 days. Test results indicate that an alkaline liquid fly-ash ratio (0.4) produces higher mechanical properties. Hence, geopolymer concrete produced in this study is found to be cost-effective and environment friendly.     

掺杂剂对聚乙炔性质影响的理论研究

以多烯烃模拟聚乙炔链,用CNDO/2方法讨论了各种掺杂剂对聚乙炔性质的影响,掺杂剂使孤子宽度收缩变窄,且p型掺杂剂比n型掺杂剂的影响更大,掺杂剂影响聚乙炔链中的电荷密度波,使电荷主要集中分布于掺杂剂附近的碳原子上。掺杂碱金属时,掺杂剂原子的最高占据轨道与聚乙炔中孤子自旋轨道之间的作用由Li到K依次增强,解释了ESR实验结果。     

The use of derivatives for establishing integration limits of chromatographic peaks

Summary The paper deals with composite peaks in which the resolution is not sufficient to allow simple area determinations with conventional integrator procedures. It is proposed to use the second derivatives of composite peaks, since the derivatives accentuate envelope perturbations due to overlapped peaks. In particular, when there are two solutes in the composite, and when the peak separation is between 2 and 4σ, the second derivative of the composite has two minima and three maxima. The second maximum is indicative of the cross point of the two solutes. This point can be used to initiate and/or terminate the integration of the components in the composite. Similarly, the second minimum occurs at a point close to the true maximum of the second peak in the composite. This point can also be used for the quantitative determination of the second component in the composite. The second derivative traces can also be integrated, but their utility in quantitative analysis of the peaks is questionable. An inversion procedure is given in which the second derivative trace is inverted to yield a trace similar to the conventional chromatograms but with better apparent resolution. In special circumstances, the inverted derivatives can be used for integration purposes.     

Investigation of some modes of flat-bed chromatography

A comparison of different chromatographic methods is presented: column liquid chromatography (CLC), thin layer chromatography (TLC), and continuous-elution flat-bed chromatography (CEFBC), which is in fact a combination of the first two methods. In CEFBC a sample is applied to a sorbent layer in a steady flow of eluent, and the components are detected directly on the layer, or immediately upon leaving it, during the separation process. It is shown that evaluation of the separation processes in CEFBC is best accomplished in terms of the parameters applicable in CLC. The reproducibility of the analytical results obtained by CEFBC is better than in the case of TLC by a factor of 6 to 10, and approaches that known for CLC.     

Generation of active surface states of gold and the role of such states in electrocatalysis

The cyclic voltammetry behaviour of gold in aqueous media is often regarded in very simple terms as a combination of two distinct processes, double layer charging/discharging and monolayer oxide formation/removal. This view is questioned here on the basis of both the present results and earlier independent data by other authors. It was demonstrated in the present case that both severe cathodization or thermal pretreatment of polycrystalline gold in acid solution resulted in the appearance of substantial Faradaic responses in the double layer region. Such anamolous behaviour, as outlined recently also for other metals, is rationalized in terms of the presence of active metal atoms (which undergo premonolayer oxidation) at the electrode surface. Such behaviour, which is also assumed to correspond to that of active sites on conventional gold surfaces, is assumed to be of vital importance in electrocatalysis; in many instances the latter process is also quite marked in the double layer region. Received: 26 July 1999 / Accepted: 7 September 1999     

Effect of barium tetraborate on the separation of tryptic digests of proteins by zone electrophoresis in uncoated capillaries

A simple, fast, efficient and reproducible method for peptide separations in CZE is reported. It consists in running tryptic digests of peptides in an uncoated capillary, in a BGE composed of tetraborate as a buffering ion, in which the typical sodium counterion is substituted with barium. Efficient absorption of this divalent cation to ionized silanols and barium silicate precipitation seem to be able to shield effectively the silica surface from separands. This is demonstrated by the fact that, when tBa(2+) ions are present in solution (from pH 8.5 up to pH 11.0), the electroendoosmotic flow is reversed; such reversal being progressively higher at higher pH values, by up to a four-fold. Separations become progressively better at higher pH values, whereas at pH 11 in sodium tetraborate they are dramatically worsened. It is further hypothesized that the barium silicate layer further protects the silica surface against dissolution and corrosion which is quite substantial at pH 11.     

Effects of structural properties of the Stern layer on the electrophoretic migration of a highly charged spherical macroion

The electrophoretic migration of a highly charged spherical macroion suspended in an aqueous solution of NaCl is studied using the molecular dynamic method. The objective is to examine the effects of the colloidal surface charge density on the electrophoretic mobility (μ) of the spherical macroion. The bare charge and the size of the macroion are varied separately to induce changes in the colloidal surface charge density. Our results indicate that μ depends on colloidal surface charge density in a nonmonotonic manner, but that this relationship is independent of the way the surface charge density is varied. It is found that an increase in colloidal surface charge density may lead to the formation of new sublayers in the Stern layer. The μ profile is also found to have a local maximum for a bare charge at which a new sublayer is formed in the Stern layer, and a local minimum for a bare charge at which the outer sublayer becomes relatively dense. Finally, the electrophoretic flow caused by the migration of the spherical macroion is studied to find that one decisive factor causing the electrophoretic flow is the ability of the macroion to carry anions in the electrolyte solution.