A new technique for separation and purification of l-phenylalanine from fermentation liquid: Flotation complexation extraction

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.