Photodegradation of atenolol under simulated solar irradiation
阿替洛尔在模拟太阳光照射下的光解

The photodegradation of atenolol was studied under simulated solar irradiation by a 1000 W xenon lamp. Photoproducts of atenolol under irradiation of 250~600 nm wavelength were identified by using HPLC and SPE-LC-MS techniques. Possible photoinduced degradation pathways were proposed. The effects of solution pH value, concentration of nitrate, presence of humic substance and bicarbonate on the photodegradation of atenolol under simulated solar irradiation were investigated. The results showed that direct photolysis of atenolol was unlikely to occur under simulated solar irradiation. Solution pH value had little effect on the kinetics of direct photolysis of atenolol. While under the irradiation of 250~600 nm wavelength, atenolol could undergo photolysis and the degradation ratio could reach 42% for 4 h irradiation. Hydroxylation of the parent compound and the cleavage of side chain were found to be the main degradation pathways. Under simulated solar irradiation, NO3- played a significant role in photosensitized degradation of atenolol, while SRFA showed limited promoting effect. It was evident that bicarbonate decreased the photodegradation of atenolol in the presence of NO3-, while humic substance inhibited the photolysis as a radical quencher and a light filter.