The present invention provides a method for removing a proteinaceous component from a liquid-phase surfactant preparation comprising (a) providing a liquid-phase surfactant preparation containing a proteinaceous component; (b) adding a complexing agent to the preparation of step (a) and allowing the complexing agent to form a complex with the surfactant; (c) simultaneously with step (b), or subsequently, adding a miscible precipitating agent to the preparation of step (a) or the product of step (b), io respectively, to form a liquid-phase reaction mixture and allowing the miscible precipitating agent to precipitate the proteinaceous component within the liquid-phase reaction mixture; and (d) separating the said complex from the precipitated proteinaceous component in the product of step (c) to provide a purified liquid-phase surfactant preparation; wherein the complex remains in solution within the liquid-phase reaction mixture, and wherein step (d) retains the complex in the liquid phase.