PubAg

Main content area

Hydrolysis and photolysis of bentazone in aqueous abiotic solutions and identification of its degradation products using quadrupole time-of-flight mass spectrometry

Author:
Song, Shiming, Zhang, Cuifang, Chen, Zhaojie, Wei, Jie, Tan, Huihua, Li, Xuesheng
Source:
Environmental science and pollution research international 2019 v.26 no.10 pp. 10127-10135
ISSN:
0944-1344
Subject:
aqueous solutions, bentazon, ethyl acetate, half life, hydrolysis, iron, irradiation, laboratory experimentation, lamps, mass spectrometry, mercury, methanol, pH, photolysis, solvents, temperature, xenon
Abstract:
Hydrolysis and photolysis of bentazone in abiotic aqueous solutions were examined under laboratory conditions. Hydrolysis was studied in different buffer solutions (pH 4.0 ± 0.1, 7.0 ± 0.1, and 9.0 ± 0.1), at different temperatures (15 °C ± 2 °C, 25 °C ± 2 °C, 35 °C ± 2 °C, and 45 °C ± 2 °C), and at different Fe³⁺ concentrations (1, 5, and 10 mg/L). Photolysis was assessed in different buffer solutions and at different solvent (methanol and ethyl acetate) concentrations (10%, 20%, and 30%) or Fe³⁺ (1, 5, and 10 mg/L) concentrations and under mercury or xenon light irradiation. Hydrolysis half-lives ranged 46–99 days at three different conditions. Photolysis half-lives ranged 2.3–7.5 h in three different conditions under mercury and xenon irradiation. Hydrolysis and photolysis of bentazone were accelerated by both alkaline conditions and elevated temperatures, and solvents and Fe³⁺ strongly enhanced bentazone degradation. Photodecomposition was much faster under a mercury lamp than under a xenon lamp. N-methyl bentazone and 6-OH bentazone/8-OH bentazone were identified as degradation products using UPLC-Q-TOF-MS. The data generated from this study could be useful for risk assessment of pesticides in the environment.
Agid:
6370213