Question

What is reverse phase and which compound will eluted first (acetamide, acetone,, and dichloroetane) in a high performance liquid chromatography with reverse phase packing? (Explain why)

Answer 1

In reverse phase high performance liquid chromatography the stationary phase is used is a organosilane which is substituted with n-octyl chains. This stationary phase is non polar and hydrophilic in nature. Now polar solvent is passed through the column. The elution will depend on polarity of samples the more polar sample will elute first and the most non polar sample elute last. Because non polar solvent will like to bond with the stationary phase and shows good affinity this will make it resides more time in the column.

As per the problem dichloromethane is least polar then acetone and then acetamide.

Thus elution order will be

Acetamide

Acetone

Dichloroethane.