Mercury Catalyzed the Hydrolysis of Quinalphos

Authors

  • Abdelhamid Esbata1*, Erwin Buncel2, Gary VanLoon2 1 Department of Chemistry, Faculty of Pharmacy, Misurata University, Misurata, Libya 2 Department of Chemistry, Queen’s University, Kingston, Ontario, Canada.

Keywords:

Catalysis, HPLC/UV, quinalphos, ESI-MS

Abstract

Hydrolysis of the organophosphorothioate compound, quinalphos (Q, O,O-diethyl O-quinoxaline-2-yl phosphorothioate) in the presence of Hg2+ was investigated at 25oC and pH 4.0, 7.0 and 10.0 using HPLC with UV detection. The hydrolysis products were 2-hydroxyquinoxaline (HQ) and O,O-diethyl phosphorothioic acid (PA). The kinetic results show clearly that mercury ion catalyzed the hydrolysis of Q, as the catalytic rate increased by presence of Hg2+. The maximum kobs was observed at the lowest pH value (pH 4.0). In the second part of this work, Electrospray ionization mass spectrometry (ESI-MS) technique was used to study how Hg2+ coordinates the substrate (Q) in ways that accelerate hydrolysis. [(PA)2 + Na + Hg]+ complex was formed; this indicates that the binding takes place between Hg2+ and the S atom.

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Published

2020-07-01

How to Cite

1.
Abdelhamid Esbata1*, Erwin Buncel2, Gary VanLoon2. Mercury Catalyzed the Hydrolysis of Quinalphos . Alq J Med App Sci [Internet]. 2020 Jul. 1 [cited 2024 Jul. 14];3(2):39-46. Available from: https://journal.utripoli.edu.ly/index.php/Alqalam/article/view/84

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