Extraction technique in which the volume (mass) of the extraction phase (liquid or solid) is substantially smaller than the sample volume (mass).
Note: The volume of extraction phase is typically \(\lt \pu{100 \upmu\!L}\) or (mass \(\lt \pu{10 mg}\)) and the sample volume is \(\gt \pu{1 mL}\).
Source:
PAC, 2016, 88, 517. 'Glossary of terms used in extraction (IUPAC Recommendations 2016)' on page 525 (https://doi.org/10.1515/pac-2015-0903)