▎ 摘　　要

NOVELTY - Synthesis of magnetic graphene oxide composite material includes uniformly dispersing graphene into concentrated nitric acid; dispersing treated graphene and ferric chloride hexahydrate into glycol solution and adding sodium citrate, sodium acetate, and polyethylene glycol; heating mixed solution; dispersing magnetic graphene into absolute ethyl alcohol and slowly adding titanium butylate or dispersing magnetic graphene into ethanol/water solution and adding urea and sodium stannate tetrahydrate; dispersing magnetic graphene oxide composite material precursor into water, and calcining. USE - Method for preparing magnetic graphene oxide composite material used for selective enrichment of phosphorylated peptide segments (claimed). ADVANTAGE - The composite material provides magnetism and has good dispersion and good biocompatibility. DETAILED DESCRIPTION - Synthesis of magnetic graphene oxide composite material comprises (A) uniformly dispersing graphene into concentrated nitric acid, cleaning, and drying; (B) dispersing treated graphene and ferric chloride hexahydrate into glycol solution, adding sodium citrate, sodium acetate, and polyethylene glycol, and uniformly dispersing to obtained mixed solution; (C) heating mixed solution at 180-220 degrees C for 8-12 hours, cleaning, and drying to obtain magnetic graphene; (D) dispersing 0.15 g magnetic graphene into absolute ethyl alcohol, adjusting pH to 8-9, slowly adding 2 ml titanium butylate, stirring, and reacting for 20-24 hours to obtain magnetic graphene oxide composite material precursor or dispersing 0.12 g magnetic graphene into 96 ml ethanol/water solution, adding 2.25 g urea and 0.329 g sodium stannate tetrahydrate, stirring, and dispersing salt to obtain magnetic graphene oxide composite material precursor; and (E) dispersing magnetic graphene oxide composite material precursor into water, hydrothermally reacting at 150-170 degrees C for 20-40 hours, cooling at room temperature, magnetically separating, washing, and calcining at 350-450 degrees C for 2-4 hours under nitrogen protection. An INDEPENDENT CLAIM is included for application of magnetic graphene oxide composite material in mass spectrometric detection by dispersing magnetic graphene oxide composite material into acetonitrile, adding peptide segment to mixed solution, uniformly mixing, performing enzymatic hydrolysis in suspension, magnetically separating supernatant, cleaning supernatant with buffer solution, suspending under alkaline condition, and taking supernatant.