硫普罗宁在汞膜电极上的伏安行为研究及应用

对硫普罗宁在汞膜电极上的伏安行为进行了研究。在pH2.87Britton Robinson缓冲液中,硫普罗宁于-0.42V(vs.Ag/AgCl)处产生良好的阴极还原峰。当硫普罗宁浓度在2.0×10-7～2.0×10-6mol·L-1范围内时与线性扫描还原峰电流呈线性关系,据此对硫普罗宁片剂的含量进行了测定,取得了满意的结果。用线性扫描与循环伏安法探讨了该体系的伏安行为,结果表明,硫普罗宁在汞膜电极上的电化学还原机理为具有吸附性的不可逆过程。     

基于功能化柔性二羧酸的新型ZnⅡ配位聚合物的合成与性质

采用水热法制备了一种新型的Zn^II配位聚合物[Zn(L1)(L2)(H₂O)]_∞ {1(CCDC: 1887307), L1= 3,3'-[1,3-苯双(羰基亚氨)]二苯甲酸，L2= 4,4'-联吡啶}，其结构经IR，元素分析和X-射线单晶衍射表征。1属单斜晶系，空间群P2₁/n，晶胞参数a=1.15592(12) nm, b=2.27630(2) nm, c=1.17693(12) nm, β=115.601(2)°, V=2792.7(5)ų, Dc=1.527 mg·m^-3, F(000)=1320, µ(MoKα)=0.938 mm^–1，Z=4, R=0.0482, wR=0.0930[I>2σ(I)]。 1呈一维“Z”字结构，在469 nm处有强荧光发射峰并具有绿色荧光。     

High-spin structure of yrast-band in 78Kr

Lifetime of levels up to 22⁺, have been measured in ⁷⁸Kr and an oblate shape is assigned to the ground state using the CSM and the configuration dependent shell correction calculations. Calculations further show that ⁷⁸Kr is highly γ-soft nucleus. The experimental Q _t values coupled with theoretical calculations indicate an oblate shape for ⁷⁸Kr at low spins and triaxial shape at higher spins     

Routine analysis by high precision gas chromatography/mass selective detector/isotope ratio mass spectrometry to 0.1 parts per mil

Stable isotope methods are potentially quite useful for validating natural or enhanced mineral degradation of contaminants. For this reason, a continuous flow gas chromatograph (GC), isotope ratio mass spectrometer (IRMS) has been coupled with a quadrupole mass selective detector (MSD) to allow simultaneous mass spectral and stable carbon isotope ratio data to be obtained from a single chromatographic analysis. This allows the target contaminant and any extra-cellular degradation intermediates to be both qualified and quantified. Previously acceptable limits of precision (0.3 parts per mil) are undesirable given the small fractionation observed during aerobic degradation. To further understand the fate of organic contaminants and to gain information about the metabolic degradative pathway employed by a microorganism, routine isotopic analyses on a range of analytes have been performed. Quantities of sample producing mass-44 ion beam signal (I(44)) of 2 x 10(-10) to 1 x 10(-8) A were analysed. When the IRMS was tuned for high sensitivity, ion source nonlinearities were overcome by peak height correction from an algorithm that was produced using known isotopic standards of varying concentrations. This led to sample accuracy of <0.01 per thousand and sample precision of 0.1 per thousand. Copyright 1999 John Wiley & Sons, Ltd.     

Investigation of the quantitative properties of the quadrupole orthogonal acceleration time-of-flight mass spectrometer with electrospray ionisation using 3,4-methylenedioxymethamphetamine

This paper describes the investigation of the potential of a quadrupole orthogonal acceleration time-of-flight mass spectrometer (Q-TOF) equipped with an atmospheric pressure ionisation interface for quantitative measurements of small molecules separated by reversed phase liquid chromatography. To this end, the detection limits and linear dynamic range in particular were studied in an LC/MS/MS experiment using 3,4-methylenedioxymethamphetamine standards and 3,4-methylenedioxyethylamphetamine for internal standardisation. In a second phase, the experiment was repeated with real biological extracts (whole blood, serum, and vitreous humour). A calibration for 3,4-methylenedioxymethamphetamine and its metabolite 3,4-methylenedioxyamphetamine was prepared in each of these matrices again using 3,4-methylenedioxyethylamphetamine as internal standard. The resulting quantitative data were compared with those obtained by liquid chromatography with fluorescence detection for the same extracts. The Q-TOF results revealed excellent sensitivity and a linear dynamic range of nearly four decades (2-10 000 pg on-column, r(2) = 0.9998, 1/x weighting). Furthermore, all the calibration curves prepared in biological material were superimposable, LC/MS/MS and LC-fluorescence, and the quantitative results for actual samples compared very favourably. It was concluded that the Q-TOF achieves a linear dynamic range for quantitative LC/MS/MS work exceeding that of fluorescence detection and at much better absolute sensitivity. Copyright 1999 John Wiley & Sons, Ltd.     

荧光法研究喹诺酮类抗菌药物和蛋白质的相互作用

用荧光光谱法、分光光度法研究水溶液中甲磺酸培氟沙星、盐酸芦氟沙星与牛血清白蛋白(BSA)的相互结合反应,表明二者以摩尔比1∶1牢固结合,结合的平衡常数分别为KPM=7 3×104L mol、KRH=9 3×104L mol。根据F rster非辐射能量转移机理,求算了甲磺酸培氟沙星、盐酸芦氟沙星与牛血清白蛋白给体-受体间距离r分别为2 82nm,2 93nm,能量转移效率E分别为0 31,0 44。喹诺酮类药物与牛血清白蛋白的相互结合作用为单一的静态猝灭过程,其作用机制为能量转移机制。     

Structure of 72,74Se at high spin

Lifetimes of high spin states up to { }=22⁺ in the yrast positive parity bands have been measured to investigate the shape evolution with increasing spin in ^{72, 74}Se. The Q _t values derived from these measurements indicate that prolate shape stabilizes for ⁷²Se, while a triaxial shape develops for ⁷⁴Se at higher spins. Comparison of the observed trend in Q _t with spin for ^{72, 74}Se with that of the corresponding kryptones isotones emphasizes the stability provided by N=38 prolate shell gap even at high rotational frequency.     

奋乃静与甲酚红的荷移反应研究

采用光度法研究了电子给予体奋乃静与电子接受体甲酚红之间的荷移反应,据此建立了荷移光度法测定奋乃静含量的方法.实验表明,奋乃静与甲酚红在丙酮介质中,室温条件下即可形成稳定的1:2型荷移络合物,该络合物的最大吸收波长为434nm,表观摩尔吸光系数为1.19×10<'4>L·mol<'-1>·cm<'-1>.奋乃静的质量浓度...