How Does SPE Extraction Work During the Whole Process?
Activation, also known as solvation, add a suitable solvent to expand the functional groups on the adsorbent and remove possible interferences on the adsorbent.
Equilibrium, remove the activated solvent to create a suitable solvent environment for sampling. Usually, use the same solvent of the sample solution. But for the ion exchange SPE cartridges, use the contrary solvent to the sample solution.
Retention, when the sample solution passes through the adsorbent, and the force between the adsorbent and certain compounds exceeds the force between the latter and the solvent, the compounds are fixed by the adsorbent, thus called retention; washing, after sampling, some of the interfering substances are retained together with the target compound.
It is necessary to add a suitable solution to remove the interferences to the greatest extent without affecting the retention of the target compound. Usually, the sample solvent for washing does not affect the recovery rate.
Elution, the strong elution ability solvent passes through the adsorbent to interrupt the interaction between the adsorbent and the retained compound so that these compounds flow out from the adsorbent with the solvent. Usually, the elution solvent which can only elute the target compound is the best choice.