After mixing with acetonitrile (1:1, v/v), filtered samples were analyzed by high-pressure liquid chromatography (HPLC, Thermo Fisher) with a ZORBAX Eclipse Plus C18 column (150 mm × 4.6 mm, 5 μm, Agilent) and a UV detector at 220 nm. The analytic method was based on previous work: Under isocratic conditions, the mobile phase was acetonitrile:water at 50:50 with a flow rate of 0.6 mL/min. The inhibition effects of chlorophyll a synthesis in model algal strain, Chlorella vulgaris was performed for detoxication study (see supporting information).