Chlorophyll a is a basic substance involved in photosynthesis

and is one of the important indicators for measuring algae biomass in water and evaluating eutrophication of lakes. The traditional calculation formula for extracting chlorophyll a was modified when the standard chlorophyll a and chlorophyll b was extracted by these organic solvents including 90% acetone

anhydrous ethanol

anhydrous ethanol∶acetone (1∶1)

anhydrous ethanol∶acetone (1∶2) and anhydrous ethanol∶acetone (2∶1). The effects of these five organic solvents on Chlorella vulgaris and Microcystis aeruginosa were analyzed under the ultrasonic treatment. It was determined that anhydrous ethanol∶acetone (2∶1) was most effective for extraction and anhydrous ethanol was considered as the best solvent in terms of efficiency

safety and environmental protection. The chlorophyll a in shallow water reservoir was monitored by multi-parameter water quality monitor at different times. The accuracy of the determination results of anhydrous ethanol under ultrasonic treatment was verified. The optimum extraction conditions of chlorophyll a by anhydrous ethanol were determined by orthogonal experiment. The optimization of chlorophyll a measurement makes the process of measuring chlorophyll a for large quantities in water more simple

fast and accurate.