Study On A Biomimetic Immunoassay-Capillary Electrophoresis Method For Determination Of Trichlorfon Residues

Trichlorfon is a kind of organophosphorus pesticide, and it is widely used in field crops. Owing to its advantages of low toxicity, high efficiency and good water solubility, it spreads widely in gardening, forestry, animal husbandry. Unfortunately, trichlorfon can penetrate body easily via the respiratory tract and skin. Its potential mutagenic and carcinogenic has drawn great attention of people in recent years. Therefore, it is in great need to develop a method to detect trichlorfon.Based on capillary electrophoresis analysis technology and bionic immunoassay technology, a new method for rapid detection of trichlorfon in vegetables is developed. The main results are as follows:(1) Preparation of trichlorfon HRP-hapten. Put trichlorfon and succinic anhydride into anhydrous pyridine and the mixture was placed in the dark. Trichlorfon hapten was obtained by ester washing and extraction under the rotary evaporation. HRP-hapten was prepared by connecting trichlorfon hapten and HRP was prepared by glutaraldehyde method(2) The preparation of trichlorfon biomimetic antibody. Biomimetic antibody that can selectively recognize trichlorfon was synthesized with the method of bulk polymerization using trichlorfon as the template molecule, methacrylate as the functional monomer and ethylene glycol dimethacrylate as the cross-linker. Trichlorfon biomimetic antibody was characterized by thermogravimetric analysis(TGA), scanning electron microscopy(SEM).(3) A novel method based on the capillary electrophoresis-immunoassay to detect trichlorfon was established. The experimental conditions were optimized in detail, and the results were as follows: the optimal pH value of working solution(PBS) for trichlorfon was 7.6, and the competing reaction time was 60 min. The limit of detection(LOD, IC15) and sensitivity(IC50) of this method were 0.13 ?g/L and 0.16 mg/L, respectively. Good recoveries of 78.8%-103% were obtained for the bean and cucumber samples spiked with trichlorfon at 0.65 ?g/L and 0.16 mg/L levels.