盐酸环丙沙星含量测定方法的研究

本文介绍了盐酸环丙沙星含量测定的离子选择电极法，紫外分光光度法和格兰线性滴定三种不同方法。用于原料药回收率的测定分别为９９．４％，９９．６７％和９９．５％；用于片剂回收率测定分别为９８．８５％，９８．８４％和９８．７３％。结果基本相同，与非水滴定法相比具有测试方便、快速等优点。     

Experiment determination of after-operating gas compositions in a transverse-flow CW high power CO2 laser

For a high-power CO₂ laser with a close-confined structure, the compositions and ratios of gas mixtures are changed due to electron impacts during the laser-operating period. As a result, the laser performance is gradually degraded, even to non-lasing output. In this paper, three different methods (a chemiluminescence, a titration analysis and a thermal conductivity measurement) are utilized to determine both the compositions and the ratios, according to different thermal and chemical characteristics of the gases. Corresponding experiments are implemented to a typical transverse-flow high-power CO₂ laser after a long-term discharge (around 15 h) with the output power decreased from an initial 3 kW to final 2 kW. There is evidence in the experiments to indicate that CO₂ decreases by 13.2% comparing with an initially optimal content. Also, the produced impurities are mostly CO and O₂ molecules with noticeable concentrations, while nitrogen–oxygen complexes are little in the gas mixtures.     

Thermodynamics of the interaction between hydroxypropyl-α-cyclodextrin and alkanols in aqueous solutions

The interactions of hydroxypropyl-α-cyclodextrin (HP-α-CD) with 1-alkanols and with some α,ω-alkanediols have been studied by calorimetric titration at 298.15 K. This technique enables the determination of the enthalpy and association constant for the complex formation, from which Gibbs energy and entropy can be derived. The results are compared to those reported for the complex formation between the native α-cyclodextrin (α-CD) and 1-alkanols or α,ω-alkanediols in the literature. Thermodynamic parameters corresponding to the transfer process of the alkanol from the native to the modified α-CD are also calculated. The results clearly show that the hydrophobic interactions are important in this process, but there are other effects like the size of the alkanol that are also of some importance.     

Bestimmung von Brom und Silber in metallorganischen Komplexen durch potentiometrische Titration

Zusammenfassung Nach Zersetzung des Komplexes wird das gebildete unlösliche Silberbromid mit metallischem Zink zu festem Silber und gelösten Bromidionen umgesetzt. Beide Komponenten werden potentiometrisch titriert. Die Standardabweichung beträgt 0,5 bzw. 1%.Teil eines Vortrags anläßlich der Tagung Euroanalysis I, 28. 8.–1.9. 1972 in Heidelberg.     

库仑非水滴定法测定药物安定

许多碱性药物的测定通常是采用非水中和滴定法,但对于含量少(毫克级)的药物用上述方法不易准确测定,为此我们尝试用非水库仑法测定。其理论依据是法拉第电解定律。只要能准确地测定电解电流和时间,物质的量就能准确地测定。与水介质不同,在水介质中指示电极使用双铂片电极可得到很明显的终点响应,而在非水介质中结果不满意。因此,我们采用通小电流极化的两个醌氢醌铂片电极作为指示电极[1]的库仑滴定法来测定碱性药物安定片。其结果符合药典法的要求。     

An Apparatus for Titrations in Liquid Ammonia

An apparatus for titrations in liquid ammonia is described. The titrations can be carried out in the absence of air, and the utility of the apparatus is demonstrated for a number of conductometric and potentiometric titrations.