▎ 摘　　要

NOVELTY - Preparing solid-phase extraction column comprises adding copper acetate and phosphomolybdic acid to the graphene dispersion and dissolving, adjusting the pH of the solution to 4-5, dissolving 1,3,5-benzenetricarboxylic acid in methanol or ethanol solvent to obtain the second solution under room temperature condition and stirring condition, dropping the second solution, separating the precipitate, washing the precipitate with absolute ethanol and deionized water in turn, vacuum drying the precursor under a protective atmosphere, heating the precursor to 700-800°C and incubating for 1-3 hours, dispersing the porous carbon microspheres in toluene solvent, carrying out the polymerization reaction under a protective atmosphere by thermal initiation or photo initiation to obtain polymerization products, crushing, grinding, and sieving polymer product, eluting substituted urea template molecule with a solvent, and drying in vacuum to obtain the extraction matrix. USE - The method is useful for preparing solid-phase extraction column. ADVANTAGE - The column has large extraction capacity and high selectivity, and can be used for the enrichment detection of low-concentration food samples instead of urea herbicides. DETAILED DESCRIPTION - Preparing solid-phase extraction column comprises (i) adding copper acetate and phosphomolybdic acid to the graphene dispersion and dissolving, adjusting the pH of the solution to 4-5 with an alkali solution to obtain the first solution, dissolving 1,3,5-benzenetricarboxylic acid in methanol or ethanol solvent to obtain the second solution under room temperature condition and stirring condition, dropping the second solution to the first solution, and continue to stirring the reaction for 0.5-1 hour after the addition is complete, separating the precipitate, washing the precipitate with absolute ethanol and deionized water in turn, vacuum drying the precursor under a protective atmosphere, heating the precursor to 700-800°C at a rate of 2-5°C/minutes and incubating for 1-3 hours, washing the cooled product with non-oxidizing acid solution and deionized water successively, vacuum drying to obtain the porous carbon microspheres, where the concentration of described graphene dispersion liquid is 3-5 mg/ml, the concentration of copper acetate and phosphomolybdic acid is respectively 0.1-0.12 mol/l, 9-10 mmol/l and second solution is 60-70 mmol/l, the mixing volume ratio of the first solution to the second solution is 1:1, (ii) dispersing the porous carbon microspheres in toluene solvent, adding 3-(methacryloyloxy)-propyl-trimethoxysilane under protective atmosphere, incubating the mixed solution and stirring for 6-12 hours at 80-95°C, , separating the precipitate, washing successively with toluene and absolute ethanol, and drying to obtain the alkenylated product, where the mass ratio of the porous carbon microspheres to the 3-(methacryloyloxy)-propyl-trimethoxysilane is 1:(3.5-4), and (iii) taking the alkenylation product, substitute urea template molecules, methacrylic acid monomers, crosslinking agents, pore-forming agent and initiators, first placing the alkenylated product, the substituted urea template molecules and the methacrylic acid monomers in a reaction in the container, adding the pore-forming agent, the cross-linking agent and the initiator in sequence, fully mixing and stirring, sealing the reaction system after deoxygenation, and carrying out the polymerization reaction under a protective atmosphere by thermal initiation or photoinitiation to obtain polymerization products, crushing, grinding, and sieving the polymer product, eluting the substituted urea template molecule with a solvent, and drying in vacuum to obtain the extraction matrix, where the mass ratio of the alkenylated product to the substituted urea template molecule, the methacrylic acid monomer, the crosslinking agent, the pore-forming agent and the initiator is 100: (1- 2): (3-8): (1.5-8): (5-15): (0.18-0.3).