Small volume of solvent used to prepare the sorbent for efficient sample processing.
Note: Principal roles include removal of contaminants from the sorbent bed to create the conditions for a stable flow of the sample solution during sampling and to facilitate wetting of hydrophobic sorbent surfaces before applying aqueous samples.
Source:
PAC, 2016, 88, 517. 'Glossary of terms used in extraction (IUPAC Recommendations 2016)' on page 541 (https://doi.org/10.1515/pac-2015-0903)