The OH initiated oxidation of chlorpyrifos (a widely used insecticide) and its photooxidation product chlorpyrifos-oxon were investigated at the large outdoor European Photoreactor (EUPHORE). The rate constants for reaction of chlorpyrifos and chlorpyrifos oxon with OH radicals were measured using a conventional relative rate method. The value of the OH reaction rate constants with chlorpyrifos and chlorpyrifos-oxon were determined to be k=(9.1±2.1)×10(-11)cm(3)molecule(-1)s(-1) and (1.7±0.9)×10(-11)cm(3)molecule(-1)s(-1) at 303±5K and atmospheric pressure. They gave an atmospheric lifetime in relation to the reaction with OH of approximately 2h and 11h for chlorpyrifos and chlorpyrifos-oxon, respectively. Photolysis was found to be unimportant relative to reaction with OH. The main products detected in the gas phase from the reaction of OH with chlorpyrifos were SO2, chlorpyrifos-oxon, 3,5,6-trichloro-2-pyridinol and diethylphosphate with molar yields of 17±5%, ∼10%, 8±4% and 30±9%, respectively.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2014.04.087DOI Listing

Publication Analysis

Top Keywords

chlorpyrifos chlorpyrifos-oxon
12
rate constants
8
reaction chlorpyrifos
8
chlorpyrifos
7
chlorpyrifos-oxon
5
reaction
5
gas-phase degradation
4
degradation chlorpyrifos
4
chlorpyrifos-oxon radical
4
radical atmospheric
4

Similar Publications

Mechanistic exploration of odorant binding protein-mediated chlorpyrifos resistance in Nilaparvata lugens: Insights from insecticide sequestration and transcriptional regulation.

Int J Biol Macromol

January 2025

Key Laboratory of Agri-products Quality and Biosafety (Ministry of Education), Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China. Electronic address:

Article Synopsis
  • Insecticide resistance in agricultural pests threatens the effectiveness of pest control strategies, and recent research points to odorant binding proteins (OBPs) as key players in this resistance.
  • Eleven OBPs were identified in Nilaparvata lugens, with OBP5 showing high expression in the head and a significant role in chlorpyrifos resistance, where its knockdown increased susceptibility to the insecticide.
  • The study confirmed that OBP5 binds to chlorpyrifos and its metabolite, with a specific amino acid crucial for this process, suggesting that targeting OBP5 may help in managing resistance by limiting the binding and sequestering of insecticides.
View Article and Find Full Text PDF
Article Synopsis
  • * Researchers found low levels of resistance to the OP insecticide phoxim in 12 populations from northern China in 2022 and identified three amino acid substitutions (A201S, G227E, and F290V) in the ace-1 gene through amplicon sequencing of over 13,000 moths.
  • * Biochemical tests showed that the A201S and F290V mutations enhanced resistance to chlorpyrifos-oxon, while G227E
View Article and Find Full Text PDF

Expression reduction and a variant of a P450 gene mediate chlorpyrifos resistance in Tetranychus urticae Koch.

J Adv Res

September 2024

State Key Laboratory of Vegetable Biobreeding, Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address:

Introduction: Understanding how insects and mites develop resistance to chlorpyrifos is crucial for effective field management. Although extensive research has demonstrated that T. urticae exhibits high resistance to chlorpyrifos, the specific resistance mechanism remains elusive.

View Article and Find Full Text PDF

The role of efflux transporters in cytotoxicity and intracellular concentration of chlorpyrifos and chlorpyrifos oxon in human cell lines.

Toxicol In Vitro

December 2024

Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada; Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada. Electronic address:

In this study, we investigated the role of two efflux transporters, p-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), in the cytotoxicity and intracellular accumulation of the organophosphate pesticide chlorpyrifos (CPF) and its active metabolite, CPF-oxon (CPFO), in a human-derived liver cell line (HepG2) and kidney epithelial cell line (HK-2). The cytotoxicity to CPF and CPFO differed between cell lines where HK-2 had lower IC50 values which could be attributed to lower basal expression and inducibility of metabolizing enzymes, transporters, and nuclear receptors in HK-2 cells. In HepG2 cells, co-exposure of CPF with a specific inhibitor of either P-gp or BCRP enhanced the cytotoxicity of CPF while co-exposure of CPFO with VRP enhanced the cytotoxicity of CPFO, suggesting the role of these transporters in the elimination CPF and CPFO.

View Article and Find Full Text PDF

Chlorpyrifos-oxon induced neuronal cell death via endoplasmic reticulum stress-triggered apoptosis pathways.

Toxicol In Vitro

December 2024

Bioelectromagnetics Key Laboratory, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China; Institute of Environmental Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China. Electronic address:

Chlorpyrifos (CPF) is one of the organophosphorus pesticides widely used throughout the world. Epidemiological studies suggested a link between CPF exposure and neurologic disorders, while the molecular mechanisms remain inconclusive. In the present study, we investigated the impacts of chlorpyrifos-oxon (CPO), the major toxic CPF metabolite, on cell apoptosis, and explored possible mechanism associated with endoplasmic reticulum (ER) stress in SH-SY5Y cells.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!