Chapter 25, Problem 25.38P

a)

Interpretation Introduction

Interpretation:

The high or low concentration of Acetonitrile in the next run of reversed-phase chromatography has to be given.

Concept Introduction:

Reversed-phase chromatography:

One of the most common mode of HPLC is the reversed-phase chromatography.  In reversed-phase chromatography, the mobile phase is more polar and the stationery phase is nonpolar or weakly polar.  The solute is more rapidly eluted from the column in reversed-phase chromatography as the mobile phase is polar.  Less polar mobile phase (solvent) has a high mobile phase strength.

This method is adequate to separate mixtures of low molecular mass.

To give the concentration of Acetonitrile in reversed-phase chromatography

b)

Interpretation Introduction

Interpretation:

The high or low concentration of Hexane in the next run of normal-phase chromatography has to be given.

Concept Introduction:

Normal-phase chromatography:

Normal-phase chromatography is another method of HPLC.  The stationery phase present in normal-phase chromatography is polar and the mobile phase is non-polar or weakly polar.  The solute particles are soluble in polar mobile phase.  This is why the mobile phase strength increases as the solvent becomes more polar.

To give the concentration of Hexane in normal-phase chromatography