Cytec Industries' Cyanex((R)) 923, 5 mL, contg. 93% of trialkyl-phosphine oxides including monohexyldioctyl 40-44, dihexylmonooctyl 28-32%, and trioctyl and trihexylphosphine oxides, was used as extractant, 0.1 mol/L in toluene, octane or aromatic-free Exxsol D 2201230 as solvent, to extract 5 mL 0.1 M lactic, AcOH, and citric acids for 1-30 min in a tab. shaker at 20-70degreesC (10degrees steps), 300 rpm. The acids were reextd. with H2O. Extn., reextn., and stratification took 2, 10 min, and 15 min, resp., regardless of solvent type. From the starting aq. solution, lactic acid was fully extd. in 4 stages with toluene-bome Cyanex((R))923. From the org, phase, it was stripped completely in 1 stage. The acids formed 1:1 complexes with the trialkylphosphine oxides. At higher temps., extn. efficiency fell by 4, 3, and 2% for the resp. acids, but stratification was faster.