Pan Mengyuan, Mu Shiyin, Li Yunfang, Yang Ya, Zhang Yuping, Chen Lingzhu, Hu Deyu
State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University Guiyang P. R. China
RSC Adv. 2022 Aug 4;12(33):21647-21654. doi: 10.1039/d2ra02601e. eCollection 2022 Jul 21.
The photolytic fate of pyridaben and its main photolysis product was investigated in different aqueous solutions. Results showed that the photolysis of pyridaben followed pseudo first-order kinetics or the hockey-stick model. In buffer solutions, the half-life of pyridaben was the shortest at pH 4, while the degradation rate within 24 h was the highest at pH 9. Humic acids (HA) at concentrations of 1-20 mg L favored the photolysis of pyridaben while fulvic acids (FA) did not have a significant effect. Nitrate at low concentrations (0.01 mM) accelerated the photolysis and Fe(iii) at high concentrations (0.01 and 0.1 mM) significantly inhibited the photolysis. The photolysis rate of pyridaben in rainwater, tap water, and river water was significantly higher than that in distilled water. The half-lives in distilled water, rainwater, tap water, river water, and pond water were 2.36, 1.36, 1.61, 1.77, and 2.68 h, respectively. Ultra-high-performance liquid chromatography/high-resolution mass spectrometry identified M328 as a photolysis product. The degradation of M328 followed pseudo first-order kinetics in distilled water, buffer solutions and aqueous solutions fortified with HA. The half-lives of M328 were in the range of 7.07-13.95 h. These results are essential for further environmental risk assessment of pyridaben.
在不同水溶液中研究了哒螨灵及其主要光解产物的光解归宿。结果表明，哒螨灵的光解遵循准一级动力学或曲棍球棒模型。在缓冲溶液中，哒螨灵在pH 4时半衰期最短，而在pH 9时24小时内的降解率最高。浓度为1-20 mg/L的腐殖酸（HA）有利于哒螨灵的光解，而富里酸（FA）则没有显著影响。低浓度（0.01 mM）的硝酸盐加速光解，高浓度（0.01和0.1 mM）的铁（III）显著抑制光解。哒螨灵在雨水、自来水和河水中的光解速率明显高于蒸馏水中的光解速率。在蒸馏水、雨水、自来水、河水和池塘水中的半衰期分别为2.36、1.36、1.61、1.77和2.68小时。超高效液相色谱/高分辨率质谱鉴定M328为光解产物。M328在蒸馏水、缓冲溶液和添加HA的水溶液中的降解遵循准一级动力学。M328的半衰期在7.07-13.95小时范围内。这些结果对于进一步评估哒螨灵的环境风险至关重要。
