Abstract: [Objective] Enzyme-linked immunoassay（ELISA）was used to evaluate the effects of three different extractants of primary water,anhydrous methanol and dichloromethane on the determination of aflatoxin M₁ in cheese powder. [Method] The average recovery rate was compared by comparing the relative standard deviation of extraction effects of primary water,anhydrous methanol and dichloromethane. [Result] When extracted with primary water,the relative standard deviation was 2.56% and the average recovery was 35.30%~51.12%. When extracted with anhydrous methanol,the relative standard deviation was 4.20%,and the average recovery was 81.32%~90.18%. When extracted with dichloromethane,the tissue status of the sample was abnormal,and the residue after nitrogen evaporation was oily,which could not be further determinated. [Conclusion] When extracted with anhydrous methanol. ELISA method had higher extraction accuracy and is more suitable for food determination.

Key words: ELISA, cheese powder, Aflatoxin M₁, extractant