Analysis on residual dynamics of chlorpyrifos and its degradation in leafy vegetables

The present experiment has been conducted to find out the dynamics of chlorpyrifos residue and its degradation by planting mustard(leafy vegetable) in exposed soil.The results indicated that the chlorpyrifos residue in mustard leaf decreased linearly after five days of spray,and tended to be steady after that.The residues increased with the increase in chlorpyrifos concentration sprayed on mustard leaf.After spraying 500× and 1500× diluted chlorpyrifos,the final chlorpyrifos residues,assayed during 7 d safe interval period and 2 d later,were higher than the national standard(0.1 mg/kg).Therefore,for food safety purposes,further studies should be taken to work out recommended concentration,spray times and safe interval period for chlorpyrifos application.