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Published on: May 21, 2019
Photochemical behavior of fenpropathrin and λ-cyhalothrin in solution
1College of Chemistry and Environmental Science, Hebei University, Baoding, 071002, China. hbupyliu@163.com.
Environmental Science and Pollution Research International
|September 11, 2013
Summary
Fenpropathrin and λ-cyhalothrin photodegradation rates depend on solvents and environmental substances. Understanding these processes aids in managing pyrethroid pollution in the environment.
Area of Science:
- Environmental Chemistry
- Photochemistry
- Organic Chemistry
Background:
- Pyrethroids like fenpropathrin and λ-cyhalothrin are widely used insecticides.
- Their persistence and fate in the environment are crucial for ecological risk assessment.
- Photodegradation is a significant environmental transformation pathway for these compounds.
Purpose of the Study:
- To investigate the photodegradation kinetics and pathways of fenpropathrin and λ-cyhalothrin.
- To determine the influence of different solvents and coexisting substances on photodegradation rates.
- To provide insights into the environmental remediation of pyrethroid contamination.
Main Methods:
- Photodegradation experiments were conducted under UV light and simulated sunlight.
- Solvents included hexane, methanol/water (1:1, v/v), and acetone.
- Gas chromatography/mass spectrometry (GC/MS) was used to identify photodegradation intermediates.
- Kinetics were analyzed using pseudo first-order models.
Main Results:
- Photodegradation followed pseudo first-order kinetics for both pesticides.
- Degradation rates decreased in the order: hexane > methanol/water > acetone.
- Acetone, humic acid, and riboflavin accelerated photodegradation, while L-ascorbic acid inhibited it.
Conclusions:
- Solvent polarity and environmental factors significantly impact pyrethroid photodegradation.
- Identified intermediates suggest specific degradation pathways.
- This research offers a theoretical foundation for developing strategies to mitigate pyrethroid pollution.
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