Ochem Lab Column Chromatography

Organic Solvent

Solid absorbant

The column

Polarity

Color (UV light also)

kp(x) [x] stat/ [x] mobile

Will be retained longer

Typically POLAR material

Polar material

Silica Gel (SiO₂) : Slightly aidic...avoid use with acid sensitive compounds...basic tend to have a larger affinity

Alumina (NaAl₂O₃): Slightly basic

Silicon Gel (C18): Less common reverse phase..nonpolar instead of polar

• Organic solvents
• -Can cahnge the polarity of mobile phase through a gradient
• -Mix nonpolar and polar solvents; polarity

-Changes with

-Solvents must by misuble

Nonpolar: Hexanes

Polar: Acetone