Abstract: To evaluate the chemical behavior of glufosinate in water, as well as its toxicity to aquatic organism, the hydrolysis properties at different temperatures and different pH values, the photolysis characteristics in water under different light intensity and wavelength, and the acute toxicity to aquatic organism were investigated using UPLC-MS/MS. The results showed that the half life of glufosinate in three buffer solutions with pH values of 5.0, 6.9 and 9.3 was 433, 693 and 533 d, respectively. It was indicated that glufosinate was stable in slightly alkaline and acidic condition. The degradation of glufosinate was positively related to the temperature. The half lives of photolysis of glufosinate under 4 500 and 8 300 lx were 1 155 and 866 h respectively, while under 365 and 254 nm were 462 and 40 h, respectively. Light intensity and wavelength obviously affected the photolytic process. The EC50/LC50 values of algae (Chlorella vulgarrs), daphnia (Daphnia magna) and zabrafish (Brachydonio rerio) to glufosinate were all more than 100 mg·L^-1, which were low toxic.

Key words: glufosinate, hydrolysis, photolysis, aquatic organism, ecotoxicity