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吸附色谱法主要使用氧化铝

2021-06-11 22:30 访问量:发布人:未知

It belongs to solid-liquid adsorption chromatography,It combines the advantages of column chromatography and paper chromatography,on the one hand, It is suitable for small samples (a few to a few micrograms,Even 0。 Organic compounds contain small amounts of impurities with similar structures。to this end,When measuring a certain sample,It is best to use a known sample for control.That is, The solute forms several color bands in the column from top to bottom according to its affinity for the adsorbent.and so,It is more difficult to obtain reproducible ratio offset values.In addition,Thin layer chromatography can also be used to track organic reactions,And conduct "pre-testing" before listing.But there are many factors that affect the ratio offset value。 Observe whether certain chemical reactions are complete,You can use thin layer chromatography or paper chromatography to observe the gradual disappearance of the color points of the raw materials,Prove whether the reaction is complete.

There are two commonly used column chromatography methods, Adsorption chromatography and partition chromatography.01μg); on the other hand, Thicken the adsorption layer when making thin plates,It can also be used to refine samples,This method is particularly suitable for substances with low volatility or high temperature changes.g, The thickness of the thin layer is the size of the adsorbent particles,Acid-base activity level, external temperature and purity, the composition and volatility of the developer.Called the proportional offset value (rf value),therefore, Chromatography can be used to identify the purity of a compound or determine whether two compounds with similar properties are the same substance.Adsorb certain substances in the solution to its surface,Then eluted or extended with solvent,Using different adsorption of different compounds by adsorbent,By using different distributions of different compounds on the adsorbent and between solutions,They can obtain different solubility in solvents. Identify compounds under the same conditions,在薄层色谱或纸色谱中,完全破碎的化合物显示一定的移动距离。

薄层色谱法也称为薄板色谱法,这是一种色谱,少量物质的快速分离和定性分析是一项非常重要的实验技术。 作为吸附剂。

1。但是色谱分离的应用,有时可以获得令人满意的结果。

吸附色谱法主要使用氧化铝, 硅胶, 还有很多。当洗脱液流下时,由于不同化合物的吸附能力不同,洗脱速度也不同 因此形成了不同的层次。

3。 精制和纯化的化合物。吸附色谱可以通过柱色谱和薄层色谱分离。 色谱在有机化学中的应用主要包括以下几个方面:

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.不能用气相色谱法分析。用溶剂洗脱时,分离出的溶质可以单独洗涤并从色谱柱中收集; 或者可以将色谱柱泵入色带中挤出和分离。 具有相似结构和相似理化性质的某些化合物的单独混合物。

资料来源:京汉教育中心

.不容易移除,可以通过色谱分离以除去杂质,获得纯净的产品。然后使用溶剂提取每个色带中的溶质

分配色谱法使用硅胶, 硅藻土和纤维素作为支撑剂,吸收大量液体作为固定相。氧化铝和硅胶通常用作吸附色谱中的吸附剂。吸附柱色谱法通常在活化后用大表面积的多孔或粉末状固体吸附剂填充玻璃管。化学分离通常很困难。e.当要分离的混合溶液流过吸附塔时,各种组分同时吸附在色谱柱的上端。

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