Pesticide Residues In Environment And Their Analysis By High Performance Liquid Chromatography (HPLC) And Solid-Phase Extraction (SPE)

With the banning of organochlorine pesticides due to their persistence, organophosphorous became more used due to relatively low persistence. There are well over one hundred registered organophosphorous pesticides currently in use. The parent compounds are highly toxic with some metabolites being up to thousand times more toxic than the parent pesticides, such is the case for methyl parathion and its degradation product, paraoxon. Organophosphorous pesticides are cholinesterase inhibitors. Therefore, the analysis into their persistence in the environment is of great significanceIn this research, high performance liquid chromatography and solid-phase extraction methods were optimized for the extraction and analysis of methyl parathion, parathion and phoxim. In order to improve the accuracy, precision and reproducibility the sample pretreatment procedures were also optimized. The best chromatographic conditions were detection wavelength of 280nm,mobile phase of methanol/water at 70/30 (v/v), mobile-phase Flow rate of 0.7mL/min, Column temperature of 35 癈, the column used was 25mmx0.1mm id, were used to determine the pesticides in the environment.The degradation of pesticides was investigated both under laboratory and environmental conditions. The results showed that hydrolysis of these three pesticides depend on both pH and the temperature. The degradation rates were in the order pH4< pH7