New High Throughput Microtiter Plates for Detection of Organophosphorous Pesticides in Environmental Samples.

Quenching of lanthanides luminescence of a novel long live Tb(III) - Ethyl 1-Allyl-1,2-Dihydro-4-Hydroxy-2-Oxoquinoline-3- Carboxylate (EADHOC) as a ligand to form a complex with molar ratio 1:3 in solution has been studied in ethanol in presence of organophosphorus pesticides both Di-chlorvos(P1) and paraoxon-Ethyl (P2). The intensity of luminescence of Tb(III) a？？(EADHOC) decrease as the concentration of pesticides increase. The quenching effect was observed with both pesticides. Direct methods of determination of pesticides under investigated have been developed by using luminescence of Tb(III) a？？(EADHOC) probe in a solution. The linear range for determination of the selected pesticides P1(Di-chlorovos) and P2(Paraoxon-Ethyl) is1 to 7 and 1 to 10 ？μM. the detection limits were 1.9？？10-7and 9.8？？10-7 ？μM for P1(Di-chlorovos) and P2(Paraoxon-Ethyl) respectively. The Thermodynamic parameters and binding constant (K) of OPs with Tb(III) a？？(EADHOC) were evaluated. Including the value of enthalpy (a？？H ) and entropy( a？？S ) changes for Probe interaction with pesticides. As the natural water sample in this study dona？？t contain the above mentioned OPs over the limit detected by the methods, a recovery study was carried out after the addition of the adequate amount of organophosphorus pesticides