Abstract: Extracted crude wheat esterase was immobilized by ion combination method. The carrier of the immobilized enzymewas a strong basic anion exchanging resin. The effects of pH value, concentration of enzyme extracting buffer and the esteraseactivity of enzyme solution on the immobilization, as well as the kinetic characteristics of the immobilization have been investigatedunder room temperature and a fixed ratio of enzyme solution to the carrier was established. The imobilized enzyme has beenremarkably inhibited even by the level of 10-7mol/L of dichlorvos. The inhibitory effect was superior to the result of free enzyme.

Key words: dichlorvos, organic phosphoric pesticide, detection, wheat esterase, ion exchanging resin, enzymeinhibition, immobilized enzyme