HLC实验步骤和方法开发.pptVIP

* The trade off between flow rate, column length and time is the same for gradient elution. When separation time is a vital issue use a short column (5-15cm) and run at high flow rate. When maximal resolution is crucial it is advisable to use a long column (20-30 cm) at normal flow rate. Compounds with a very steep velocity curve (e.g. proteins) does not benefit from long columns. These compounds reaches quickly (after a few centimeter of acceleration) a k’=0 i.e. no stationary phase interaction. When applying steep gradients it is actually counter product to use a long column as the compounds reaches k’=0 (no chromatography) before leaving the column. The last part of the column then only add band broadening. 开发液相色谱方法的考虑因素 分离度是色谱分离中主要考虑的因素 除分离度之外，在开发色谱方法时，以下几个因素也都要考虑： 灵敏度 载样量 分析速度 溶剂损耗 成本 容易使用 色谱柱寿命 效率 THANK YOU SUCCESS * * 可编辑 * In general, development of a HPLC method often follows the steps outlined here. As you can see, choosing a detector is an important part of the method development process. Correct (or incorrect) detector selection will influence the success of the method. Limits of detection, limits of quantitation are directly influenced by the detector choice. Other factors can be indirectly influenced as well. For example, a very selective detector (MS or FLD) can minimize the need for perfect separation conditions. * * All HPLC detectors, regardless of design should provide the functions outlined here. * * A prefect detector design would provide all of the listed features. Unfortunately, no such detector exists and any detector design is forced to make compromises. As we will see throughout the presentation, knowledge of these compromises and the effects of the obtained results allow users to use detectors for their maximum benefit. * Sensitivity is one of the most widely cited detector requirements. Generally speaking, most users demand detector that are highly sensitive to their compounds of interest. Many users describe sensitivity s