A method for the selective extraction of camphorsulfonic, phenylpropionic, and mandelic acid enantiomers from racemic mixtures is proposed. The method uses supercritical fluid extraction (SFE) and in situ chiral precipitation by the addition of specific alkaloids. The SFE extracts obtained were analyzed by high performance liquid chromatography (HPLC) with indirect UV detection. Two different ways of introducing the reagents into the extraction cell were compared. One way was the conventional involving spiking onto diatomaceous earth; in the other, reagents were dissolved in the modified-CO2 fluid for pumping and trapping in the extraction cell, using different programmed cycle times. The latter procedure was found to provide much better precision than the former. In some cases, one enantionter was made more readily soluble in CO2 and was extracted with it, while the other, insoluble enantiomer, remained in the extraction cell. Racemic acid mixtures supported on diatomaceous earth as inert support were selectively extracted with high recoveries for the enantiomers of interest (viz. 98% and 2% for R- and S-10-camphorsulfonic acid, respectively, with strychnine; 1% and 99% for R- and S-phenylpropionic acid, respectively, with brucine; and 98% and 2% for R- and S-mandelic acid, respectively, with quinine). The proposed method enables enantioselective extraction by in situ SFE as a preparation and analysis technique for the production of enantiomers in a high optical purity.