title: Time-resolved fluorescence sensing of pesticides chlorpyrifos, crotoxyphos and endosulfan by the luminescent Eu(III)-8-allyl-3-carboxycoumarin probe.
abstract: This work describes the application of time resolved fluorescence in microtiter plates for investigating the interactions of europium-allyl-3-carboxycoumarin with pesticides chlorpyrifos, endosulfan and crotoxyphos. Stern-Volmer studies at different temperatures for chlorpyrifos and crotoxyphos shows dynamic and static quenching mechanisms respectively. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence variations of the probe in solution. The detection limits are 6.53, 0.004, 3.72 μmol/L for chlorpyrifos, endosulfan, and crotoxyphos, respectively. The binding constants and thermodynamic parameters of the pesticides with probe were evaluated. A thermodynamic analysis showed that the reaction is spontaneous with negative ΔG. Effect of some relevant interferents on the detection of pesticides has been investigated. The new method was applied to the determination of the pesticides in different types of water samples (tap, mineral, and waste water).
authors: Chemistry Department, Faculty of Science, Suez Canal University, 41522 Ismailia, Egypt. Electronic address: azab2@yahoo.com.
authors: Hassan A
authors: HA
authors: Azab
authors: Chemistry Department, Faculty of Science, Suez Canal University, 41522 Ismailia, Egypt; Chemistry Department, Faculty of Science and Arts, Aljouf University, P.O. Box #2014, Skaka 41421, Saudi Arabia.
authors: Gasser M
authors: GM
authors: Khairy
authors: Chemistry Department, Faculty of Science, Suez University, Suez, Egypt.
authors: Rasha M
authors: RM
authors: Kamel
mesh_terms: D004390:Chlorpyrifos / Q000032:analysis*; D056831:Coordination Complexes / Q000737:chemistry*; D003374:Coumarins / Q000737:chemistry*; D004726:Endosulfan / Q000032:analysis*; D057230:Limit of Detection; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods; D009943:Organophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D013816:Thermodynamics; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D056831:Coordination Complexes; D003374:Coumarins; D049408:Luminescent Agents; D009943:Organophosphorus Compounds; D010575:Pesticides; D014874:Water Pollutants, Chemical; C574931:europium-3-carboxycoumarin; D014867:Water; C000518:crotoxyphos; D004390:Chlorpyrifos; D004726:Endosulfan
keywords: Organophosphorous; Static quenching; Stern–Volmer; Time-resolved fluorescence