Combining solvent sublation with complexation extraction, flotation complexation extraction (FCE) is proposed for the first time. This new technique was used to separate and purify L-phenylalanine from fermentation liquid with good results. The effects of extraction solvent, pH of the solution, NaCl concentration. concentration of di-(2-ethylhexyl) phosphoric acid (D2EHPA) in organic phase, nitrogen flow rate and flotation time on the separation efficiency Of L-phenylalanine were investigated in detail, and the optimal conditions for FCE were obtained. The flotation product from the fermentation liquid under optimal conditions, after back-extraction and re-crystallization, was characterized by FTIR and HPLC, and its purity was more than 98%. Furthermore. the mechanism of FCE was also primarily discussed. (C) 2008 Elsevier B.V. All rights reserved.