At the same time, the oxidation-extraction photometry method was used to determine the ROS generated in solutions under the irradiation of ultrasound. In this reaction process, DPCI was oxidized by ROS into diphenylcarbazone (DPCO), which can be extracted by the mixed organic solvent of benzene and carbon tetrachloride, showing maximum MPC-3100 at 563 nm. The results shown in Fig. 5 are the absorbance difference values of solutions with ultrasound and kept in dark. It can be seen that the absorbance of DPCO at 563 nm increases with the increase of ultrasonic time in the presence and absence of EB. However, the absorbance of DPCO in DPCI–EB solutions is higher than that of single DPCI solution at any ultrasonic time. These results indicate that the synergistic effects of ultrasound and EB can produce more ROS than single ultrasound. It can be inferred that EB can be activated by ultrasound and generate ROS and the quantities of ROS increase with the increase of ultrasonic time. Therefore, the degree of damage of BSA molecules becomes more serious.