Why does the elution solvent require acid?
Due to the unique hydrogen-donor retention mechanism of the sorbent, acid is required to distrupt interaction of the polar compounds with this sorbent. The acid protonates the basic compounds, rendering them more polar and more easily releasing them from the sorbent. Increasing the % trifluoroacetic acid (from 0.1% to 0.4%) in the elution solvent can facilitate the reduction of elution volumes. Elution volumes of 400 uL (in multiple aliquots) are common for most analytes.
