Optimal degradation of organophosphorus pesticide at low levels in water using fenton and photo-fenton processes and identification of by-products by GC-MS/MS

This study aiming to determine the optimal conditions degrade an organophosphate pesticide diazinon (DZN) at low levels concentrations (μg.mL−1) and identify by-products generated. The degradation processes utilized were Fenton photo-Fenton. iron concentration [Fe2+], hydrogen peroxide [H2O2], solution pH are investigated parameters. Doehlert three-parameter experimental design was applied model optimize both processes. mathematical models suggested assessed validated by application of analysis variances ANOVA. In case process, greatest yield (79%) obtained [Fe2+] = 35 mg.L−1 (0.63 mmol.L−1), [H2O2] 423 (12.44 5.0. photo-Fenton maximum (96%) under 29 (0.52 258 (7.59 mmol.L−1) 4.6. QuEChERS (quick, easy, cheap, effective, rugged, safe), as extraction technique, GC-MS/MS (gas chromatography coupled with triple quadrupole mass spectrometry) used DZN. identified compounds diazoxon, triethyl phosphate, thiophosphate, 2-isopropyl-5-ethyl-6-methylpyrimidine-4-ol, 2-isopropyl-6-methylpyrimidine-4-ol (IMP) hydroxydiazinon. Three possible pathways for have been hydroxylation, oxidation hydrolysis likely probable mechanisms.