Photochemical behavior of fenpropathrin and λ-cyhalothrin in solution

Liu, P. Y.; Li B.,; Liu, H. D.; Tian, L.

Photochemical behavior of fenpropathrin and λ-cyhalothrin in solution

2014

Liu, P. Y. | Li B., | Liu, H. D. | Tian, L.

The photodegradation processes of fenpropathrin and λ-cyhalothrin were studied in hexane, methanol/water (1:1, v/v), and acetone in both ultraviolet light and simulated sunlight. Intermediates in the photodegradation process were identified using gas chromatography/mass spectrometry (GC/MS), and the analysis of intermediates was used to speculate on possible photodegradation pathways. The photodegradation processes of fenpropathrin and λ-cyhalothrin followed pseudo first-order kinetics. The photodegradation rates varied according to the solvent in decreasing order: hexane > methanol/water (1:1, v/v) > acetone. The effects of substances coexisting in the environment on the photodegradation of pyrethroids were also investigated in the research. Acetone, humic acid, and riboflavin increased photodegradation rates while L-ascorbic acid slowed the process. This study provides a theoretical basis for the removal of pyrethroid pollution from the natural environment.

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