Question

What is the difference between normal phase and reverse phase chromatography? In each case would the more or less polar material be eluted first?

Answer 1

Normal phase HPLC - stationary phase used is polar silica substance and elutants used are non-polar and slightly polar organic solvents.

Reverse Phase HPLC- stationary phase used is non-polar C18 sustance and elutants used are more polar protic solvents (H2O, THF, MeOH, acetonitrile).

In normal pHase HPLC non-polar substances will eluted first followed by polar substances.

In reverse phase HPLC polar substances will eluted first followed by non-polar substances.