biostudies-literatureRuttler FDeutsche ForschungsgemeinschaftUniversität Hohenheim4731-4740https://www.ebi.ac.uk/biostudies/studies/S-EPMC10352415biostudies-literatureUnknown415(19)Countercurrent chromatography (CCC) is a preparative instrumental method where both the mobile and stationary phases are liquids and which are predominantly used for the isolation of natural products. In this study, we widened the scope of CCC by using it as an instrumental method for the direct enrichment of the free sterol fraction from plant oils to which they contribute with ~ 1%. For the enrichment of sterols in a narrow band, we employed the so-called co-current CCC (ccCCC) mode in which both liquid phases of the solvent system (here: n-hexane/ethanol/methanol/water (34:11:12:2, v/v/v/v)) are moved at different flow rates in the same direction. Different from previous applications of ccCCC, the lower and predominant "stationary" phase (LP_s) was pumped twice as fast as the Analytical and bioanalytical chemistrySample preparation of free sterols from vegetable oils by countercurrent chromatography in co-current mode.PMC10352415VE 164/20-1Cannas JRuttler FOrmos RHammerschick TVetter WSchlag SfalseSample preparation of free sterols from vegetable oils by countercurrent chromatography in co-current mode.Countercurrent chromatography (CCC) is a preparative instrumental method where both the mobile and stationary phases are liquids and which are predominantly used for the isolation of natural products. In this study, we widened the scope of CCC by using it as an instrumental method for the direct enrichment of the free sterol fraction from plant oils to which they contribute with ~ 1%. For the enrichment of sterols in a narrow band, we employed the so-called co-current CCC (ccCCC) mode in which both liquid phases of the solvent system (here: n-hexane/ethanol/methanol/water (34:11:12:2, v/v/v/v)) are moved at different flow rates in the same direction. Different from previous applications of ccCCC, the lower and predominant "stationary" phase (LP_s) was pumped twice as fast as the 2023-01-01T00:00:00Z2023 Aug2025-04-04T20:33:15.355Z2025-04-04T20:33:15.355ZS-EPMC103524153728502510.1007/s00216-023-04766-9