Distribution Coefficients of Lipopeptide Biosurfactant in Different Solvents and its Separation from a Surfactant/Polymer Mixture in Aqueous Solutions

Abstract

The distribution coefficients of lipopeptide biosurfactant in four different commercially available organic solvents and water were determined by HPLC. A method with a high recovery of 92.1% for isolation of the lipopeptide in a surfactant/polymer mixture in aqueous solutions was established by using the combined means of acid extraction, alkaline conversion and acid re-extraction. The results showed that the lipopeptide distribution coefficients range from 0.010 to 61 at different pH values in different organic solvents, which is an indicator for optimizing the process of separation of lipopeptide biosurfactant in surfactant/polymer mixtures in aqueous solutions. The proposed separation method was used to determine the lipopeptide biosurfactant concentration in production fluids of the Daqing oil field. The concentrations were 6.57 μg/L and 4.56 μg/L.