▎ 摘　　要

NOVELTY - A polytetrafluoroethylene micro-extraction column has alternating layered structure of polydopamine and graphene layers. The total number of graphene layers is 3 or more. USE - Polytetrafluoroethylene micro-extraction column for measuring polycyclic aromatic hydrocarbon material in food, water and soil. ADVANTAGE - The micro-extraction column having uniform structure is produced by simple method, and is compact. The extraction column has excellent absorption and enrichment effect. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for polytetrafluoroethylene micro-extraction column, which involvespreparing 1-2 mg/mL dopamine alkaline solution having pH of 8.5-9, flowing solution through a clean polytetrafluoroethylene tube, washing with water after reaction, drying to obtain modified polydopamine polytetrafluoroethylene tube, passing 0.5-1 mg/mL aqueous solution of graphene oxide, sealing ends, removing after heating, washing, drying, and repeating processes to obtain graphene multilayer coated polytetrafluoroethylene tube.