Comparison of Two Aqueous Two-Phase Systems for Extracting Microcystin-LR from Algae Pulp

Abstract

In this study, aqueous two-phase systems of polyethylene glycol 2000/C₄O₆H₄KNa and polyethylene glycol 2000/Na₂SO₄ were investigated for the extraction of extract microcystin-LR. These two aqueous two-phase systems were optimized by varying the molecular weight of polyethylene glycol, the concentrations of polyethylene glycol 2000, the inorganic salts, added ionic strength, rotation speed and the pH value. The results showed that higher recovery could be achieved by an aqueous two-phase system of polyethylene glycol /Na₂SO₄ when compared with an aqueous two-phase system of polyethylene glycol /C₄O₆H₄KNa. The recovery of microcystin-LR can reach about 60.6% under the optimum extraction conditions [polyethylene glycol 2000 8%(w/w), C₄O₆H₄KNa 9%(w/w), added ionic strength I=0, rotation speed 4000r/min, pH=5].