Chapter 19, Problem 1Q

Interpretation Introduction

Interpretation:

The reason for the level of elution solvent to not drop below the top of the adsorbent should be determined.

Concept introduction:

Liquid chromatography is used for purification of high boiling compounds. It is known as column chromatography. In liquid chromatography, column is packed by stationary phase. Usually, a solid adsorbent with a liquid coated on it is used as stationary phase. Often a pure liquid or solution of liquids composes the mobile phase. It is also called the elution solvent.

The elution solvent comes down the column under the influence of gravity. Selective interactions are responsible for separation of the sample among stationary and mobile phases. The sequence of elution of compounds from sample depends on the polarity of mobile and stationary phases.

Explanation of Solution

The packing of a column is an important factor for the success of the chromatographic separation in addition to the choice of adsorbent and elution solvents.

If cracks or channels are present in the column or if the top surface is not flat, then separation in the chromatographic column will be poor.

If the adsorbent becomes dry, it may drift away from the walls of the column and form channels. Once a chromatographic separation begins, it is essential to finish it without interruption.