Fluorimetric Determination of Gatifloxacin in Aqueous,Pure and Pharmaceutical Formulations

Abstract

A spectrofluorimetric method was developed for the determination of gatifloxacin. The emission peak for gatifloxacin was recorded at 495 nm upon excitation at 291 nm. The fluorescence process was pH dependent. The dynamic range for the method was 16–80 ng ml^?1with detection limit of 3.97 ng ml^?1. A linear relationship between the fluorescence intensity and the concentration of gatifloxacin solution was obtained with r ² of 0.9968. The method has successfully applied to the determination of gatifloxacin in pure, authentic and aqueous samples.     

加雷沙星的吸附伏安法测定

在0.3mol·L-1KH2PO4-Na2HPO4(pH6.40)底液中,加雷沙星(Garenoxacin,简称GRX)在汞电极上有一线性扫描还原峰,峰电位EP=-1.12V(vsAg/AgCl),该峰具有明显的吸附性;吸附粒子为GRX中性分子,测得GRX在汞电极上的饱和吸附量Гs=3.92×10-11 mol·cm-2,每个GRX分子所占电极面积为1.94nm2,GRX在汞电极上的吸附符合Langmuir吸附等温式;测得吸附系数β=1.14×106,25℃时的吸附自由能ΔGθ=-29.62kJ·mol-1,电极反应电子数n=2,不可逆体系动力学参量αna=1.04,表面电极反应速率常量ks=0.25s-1;建立了吸附溶出伏安法测定GRX的最佳条件,方法的检出限为2.0×10-8 mol·L-1.     

Euler-Mahonian statistics on ordered set partitions (II)

[E. Steingrímsson, Statistics on ordered partitions of sets, arXiv: math.CO/0605670] introduced several hard statistics on ordered set partitions and conjectured that their generating functions are related to the q-Stirling numbers of the second kind. In a previous paper, half of these conjectures have been proved by Ishikawa, Kasraoui and Zeng using the transfer-matrix method. In this paper, we shall give bijective proofs of all the conjectures of Steingrímsson. Our basic idea is to encode ordered set partitions by a kind of path diagrams and explore the rich combinatorial properties of the latter structure. As a bonus of our approach, we derive two new σ-partition interpretations of the p,q-Stirling numbers of the second kind introduced by Wachs and White. We also discuss the connections with MacMahon's theorem on the equidistribution of the inversion number and major index on words and give a partition version of his result.     

Loose‐powder technique for X‐ray fluorescence analysis of ancient pottery using a small (100 mg) powdered sample

A molded‐loose‐powder technique using a small powdered sample (100 mg) was developed for the X‐ray fluorescence analysis of 22 components (Na₂O, MgO, Al₂O₃, SiO₂, P₂O₅, K₂O, CaO, TiO₂, MnO, Fe₂O₃, V, Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, and Pb) in ancient pottery. This loose powder specimen was prepared by pressing the small powdered sample into a sample holder, formed from a stainless steel disk (48‐mm diameter × 0.8‐mm height) with a hole (11‐mm diameter), by hand. Calibration standards were prepared by homogenizing chemical reagents containing these 22 analytes using the concentration ranges of 166 ancient potteries and three clay materials from Japan. The calibration curves of these benchmark mixtures exhibited a good linearity (correlation coefficient, r = 0.990–1.000), accuracy, and reproducibility compared with those of other synthesized specimens and three reference standards. The lower limits of detection were less than tens of mg kg^?1 (e.g., 94 mg kg^?1 for Na₂O, 11 mg kg^?1 for P₂O₅, 1.1 mg kg^?1 for Rb, and 0.9 mg kg^?1 for Y). Using the present method, we determined 22 components in two prehistoric potteries from Japan. The advantage of this method is that only a small amount of sample is required, which can be prepared easily and rapidly and reused for other analyses. Copyright © 2012 John Wiley & Sons, Ltd.     

碱熔-标准物质法-电感耦合等离子体发射光谱(ICP-AES)法测定硅酸盐岩中10种主量元素

硅酸盐岩元素的准确测定是其地球化学分析研究的基础,其主量元素含量通常可以采用电感耦合等离子体发射光谱(ICP-AES)法测定,但其测定方法的系统性研究相对缺乏,尤其是样品前处理和基体干扰的有效消除两方面。前处理过程中,考察不同熔剂用量对硅酸盐岩样品的分解能力,发现当熔剂与样品比例达到6:1后,熔珠为纯色透明,经稀硝酸提取后溶液澄清,确定了硅酸盐岩前处理时熔剂与样品的最佳配比。测定过程中,通过考察基体匹配法和标准物质法两种基体干扰消除方法对测定结果的影响,发现当采用与岩性一致或者接近的标准物质绘制校准工作曲线时,基体干扰消除效果更好,更适用于测定硅酸盐岩10种主量元素含量。据此,建立了硅酸盐岩经偏硼酸锂熔融,稀硝酸振荡提取处理,以标准物质法绘制校准工作曲线,采用ICP-AES法同时测定SiO2、Fe2O3、Al2O3、CaO、K2O、MgO、Na2O、TiO2、P2O5、MnO 10种成分含量的方法。对岩石标准物质GBW07107进行分析测定,方法的相对标准偏差(RSD)为0.17%～0.75%,方法检出限为0.001%~0.016%,满足硅酸盐岩样品元素定量分析的要求,而且操作简单快速,环境污染小,适用于大批量样品分析。     

Two new bismuth salts with succinic acid: synthesis,structural, spectroscopic and thermal characterization

Two novel bismuth succinate hydrates, namely, poly[[diaqua(μ₃-butane-1,4-dicarboxylato)hemi(μ-butane-1,4-dicarboxylato)bismuth] monohydrate], {[Bi(C₄H₄O₄)_1.5(H₂O)₂]·H₂O}_n ( 1 ), and poly[[μ-aqua-aqua(μ₃-butane-1,4-dicarboxylato)(μ-butane-1,4-dicarboxylato)-μ-oxido-dibismuth] monohydrate], {[Bi₂(C₄H₄O₄)₂O(H₂O)₂]·H₂O}_n ( 2 ), have been synthesized. Their crystal structures were determined by single-crystal X-ray diffraction and the compounds were characterized by IR and Raman spectroscopy, powder X-ray diffraction and thermal analysis. The crystal structure analysis revealed that the compounds are coordination polymers, with 1 having a two-dimensional layered structure and 2 displaying a three-dimensional (3D) framework. Fully deprotonated succinate anions (C₄H₄O₄²⁻) in two different conformations (trans and gauche) are included in their composition. The Bi³⁺ cations are surrounded by O atoms from the carboxylate groups of succinate anions and aqua ligands. BiO₉ coordination polyhedra in 1 are connected in pairs by edges. These pairs are bound together by bridging succinate ligands to form layers. Bismuth coordination polyhedra of two different types (BiO₉ and BiO₇) in 2 are connected by edges to form infinite ribbons. Ribbons of polyhedra with bridging succinate ligands form a 3D polymeric structure.     

基于OBE和EHS理念的制药过程安全与环保课程体系建设

“制药过程安全与环保”为制药工程专业本科生必修核心课程，但其课程体系不完善，基于OBE和EHS理念，从课程目标、课程内容、课程思政、教材、教学方法、课程考核与评价方法等方面对该课程进行了建设和完善，取得了一些创新性成果与经验，制定了教学目标，创新性地设置了课程内容，开展了课程思政，主编了教材，提出了适宜的教学方法，建立了课程考核与评价方法，可以为全国其他高等院校类似课程的教学与建设提供有益的借鉴。     

Bowl-shaped hollow N-doped carbon as an electrochemical platform for the highly selective and sensitive electrochemical detection of isoprenaline in pharmaceutical injection

In this study, bowl-shaped N-doped hollow carbon sphere-containing mesoporous nanomaterials (BNHC) were used for the ultrasensitive electrochemical detection of isoprenaline (ISOP). The linear ranges of the BNHC-based sensor were as follows: 0.05 – 15 μM; 15 – 70 μM, with the limit of detection (LOD) of 6.8 nM. And the BNHC-based electrochemical sensor showed a good current response to ISOP and maintained 95.6 % of the initial current after 30 days of storage. Notably, when the BNHC-modified sensor was used to detect the actual ISOP injection and urine samples, the sensor exhibited satisfactory recovery.