usp31-621色谱法中文译稿.docVIP

621 CHROMATOGRAPHY色谱法 INTRODUCTION介绍 This chapter defines the terms and procedures used in chromatography and provides general information. Specific requirements for chromatographic procedures for drug substances and dosage forms, including adsorbent and developing solvents, are given in the individual monographs. 此章节定义了色谱法中用到的术语和步骤，并提供了通用信息。对于原料药和成药的色谱步骤的具体要求，包括吸附剂和展开溶剂，在具体各论中给出。 Chromatography is defined as a procedure by which solutes are separated by a dynamic differential migration process in a system consisting of two or more phases, one of which moves continuously in a given direction and in which the individual substances exhibit different mobilities by reason of differences in adsorption, partition, solubility, vapor pressure, molecular size, or ionic charge density. The individual substances thus separated can be identified or determined by analytical procedures. 色谱法是应用溶质在两相或多相系统中的差速迁移来进行分离的技术，其中一相持续地向特定方向移动，而由于物质在吸附性、分配、溶解性、气体压力、分子大小、或离子电荷密度上的差异，会显示出不同的移动性。由此分开的这些单个物质可以通过分析过程鉴别或测定。 The general chromatographic technique requires that a solute undergo distribution between two phases, one of them fixed (stationary phase), the other moving (mobile phase). It is the mobile phase that transfers the solute through the medium until it eventually emerges separated from other solutes that are eluted earlier or later. Generally, the solute is transported through the separation medium by means of a flowing stream of a liquid or a gaseous solvent known as the “eluant.” The stationary phase may act through adsorption, as in the case of adsorbents such as activated alumina and silica gel, or it may act by dissolving the solute, thus partitioning the latter between the stationary and mobile phases. In the latter process, a liquid coated onto an inert support, or chemically bonded onto silica gel, or directly onto the wall of a fused silica capillary, serves as the stationary phase. Partitioning is the predominant mechanism of separation in gas–liquid chromatography, p