The General Usage of SPE Cartridge
Activation is also called solvation. We can add appropriate solvent to spread the functional group on the adsorbent, and also remove possible chaff interferent. As for reverse-phase adsorbent, we often use a solvent with medium polarities, such as methyl alcohol. When referring to the normal-phase adsorbent, a solvent with weak polarity or nonpolar solvent, such as hexane, is always applied.
To remove the activated solvent and make the suitable solvent environment for loading the sample, we often use the solvent which is the same with the solvent in the solution sample. As for the ion exchange SPE column, if the sample is alkali compound, normally we need to add acid into the equilibrium liquid. On the contrary, we need to add alkali.
When the solution sample goes through the adsorbent, the effort between adsorbent and certain compounds surpasses the effort between compounds and the solvent, these compounds will be fixed by the adsorbent. This process is called Retention.
After the sample is loaded, some chaff interferent and target compounds will be retained at the same time. We need to add appropriate solvent to remove the chaff interferent to the maximum possible extent, and also not to affect the retention of the target compounds.