What precautions must be taken when you introduce a mixture of compounds to be separated onto a liquid chromatography column?

The slim exit of the column is first persisted with glass wool or a permeable plate in order to sustain the column packing element and keep it from getting out of the tube. Then the adsorbent solid, which is usually a silica, is firmly packed into the glass tube to make the separating column. The packing of the non-moving phase into the glass column must be done with precaution to create an even distribution of material. An even distribution of adsorbent material is very important to lessen the existence of air bubbles and/or channels inside the column. To finish preparing the column, the solvent to be used as the mobile phase is delivered through the dry column. Then the column is said to be "wetted" and the column must stay wet throughout the entire procedure. Once the column is properly prepared, the sample to be separated is placed at the top of the wet column.