The Reason of Poor Sample Recovery When Using SPE
Solid-phase extraction (SPE) is a useful method of sample preparation. By sorting onto a disposable solid-phase cartridge, it can concentrate and purify analytes from solution. But sometimes, the results are unsatisfied with the poor and non-repeatable sample recovery. To avoid it, we’d better find out the reason.
First, wrong sorbent bed. According to the working principle of SPE, we must choose the sorbent bed fully retained with the analyte of interest. Poor recoveries will be found when the sample is leaching during load and wash.
Second, wrong wash solvent. The past experience has fully proved that, only if the wash solvent is strong enough, the most interference can be removed without eluting any sample.
Third, wrong elution solvent. We must make sure that the eluting solvent we choose is strong enough to elute 100% of the sample, as while as weak enough to leave more interfering contaminants on the SPE column.
Perfect balance of the three parameters: the sorbent, the wash solvent, and the elution solvent, will help us achieve the best sample recovery from solution.