[Study on the degradation of residual insecticides on and in the vegetables and washing off method]

The degradation of residual insecticide in the vegetables is according to the first order of chemical dynamitic reaction. The half-life of insecticide on/in the vegetable can be calculated through a series sampling and analysis the residual amount to obtain a regression equation or by a simplified equation. Although the total amount of residual insecticide degraded according to the first order of chemical dynamitic reaction, the lost of the partial insecticide which absorbed in the leaves seems likely according to a more complicated exponent curve which has been described. The adsorbed residual insecticide (on the leaves) was easy washed away. The non-ionic detergent is more effect than water. But the absorbed insecticide (in the plant tissue) is hard to wash out.