A procedure for chromatographic separation in which the mobile phase is passed through the chromatographic bed after the application of the sample.
Sources:
Orange Book, 2nd ed., p. 92 (https://media.iupac.org/publications/analytical_compendium/)
PAC, 1993, 65, 819. 'Nomenclature for chromatography (IUPAC Recommendations 1993)' on page 824 (https://doi.org/10.1351/pac199365040819)