Residues and Dissipation of Fenitrothion in Green Bean (Phaseolus vulgaris) and Soil

The objective of this study were to determine the residue levels of fenitrothion in/on green bean pods, leaves, and soil under the treated plant and to identify the degradative metabolites of fenitrothion in soil under the treated plant. The results showed half-life ( t 1 / 2) values of 1.79, 2.00, and 6.08 days for fenitrothion in green bean pods, leaves, and soil, respectively. The results of GC-MS analysis of soil extracts under the treated plant showed that, at zero time, unchanged fenitrothion was found. The proportion of fenitrothion in soil extracts detected decreased with the time. GC-MS analysis of soil extracts shows the presence of compound having the formula of C 7 H 7 NO 3 which is suggested to be 3-methyl-4-nitrophenol which is the major degrades of fenitrothion in soil. The other transportation products were not founded. According to the maximum residue limits (MRLs), the preharvest intervals (PHIs) of fenitrothion on green bean pods were 13 days after the treatment.