A sample containing capsaicin and dihydrocapsaisin was inserted for reversed HPLC analysis. Which is more polar? Which will elute first? Which will have a larger retention time? Solution Dihyrocapsaicin is more polar and capsaici n is non - polar and hydrophobic . A sample containing capsaicin and dihyrocapsaicin in reversed HPLC , Capsaicin is first elute, because the reverse phase HPLC uses a non-polar / hydrophobic stationary phase and a polar mobile phase. Capsaicin only differ with dihyrocapsaicin by only double bond. When we use polar solvent, the cyano group will react with Capsaicin through pi-pi interaction, since the Capsaicin is more concentrated in the polar solvent that is the mobile phase it will elute first. Dihyrocapsaicin have larger retention time. Because it’s second elute. .