Column Chromatography MIT Digital Lab Techniques Manual
[MUSIC PLAYING] PROFESSOR 1: Column chromatography. The purification of chemicals is one of the most important jobs of a research chemist. Perhaps the most common purification technique in an organic laboratory is column chromatography. This technique takes advantage of the different polarities of different compounds to separate mixtures, frequently on the grand scale. Technically, carbon chromatography can be challenging, but with a little practice, you will be able to separate mixtures of compounds consistently and successfully. As the name suggests, a column of adsorbent, either silica or alumina, is packed into a glass tube with a stopcock at the bottom. The sample is applied to the top of the adsorbent and solvent is run through the column until the compound is flushed out of the bottom. In most cases, flash column chromatography is used, meaning that pressure is applied to the top of the column, resulting in faster running times and better separation. Before you can...