▎ 摘　　要

NOVELTY - Polycyclic aromatic hydrocarbons detection involves dissolving iron (III) sulfate heptahydrate, graphene oxide and iron (III) hexahydrate in water under sonication for 20-30 minutes, and then passing into inert gas at 50-70 degrees C for 50 minutes. The solution is stirred under strong conditions followed by adding certain amount of ammonia at 50-70 degrees C for 30-50 minutes, washed with magnetic separation, and then vacuum dried to get iron (III) oxide composite. USE - Method for detecting polycyclic aromatic hydrocarbons (claimed). ADVANTAGE - The method enables to detect polycyclic aromatic hydrocarbons in a simple and cost-effective manner with fast response, high sensitivity, good stability, good selectivity and width detection line. DETAILED DESCRIPTION - Polycyclic aromatic hydrocarbons detection involves dissolving iron (III) sulfate heptahydrate, graphene oxide and iron (III) hexahydrate in water under sonication for 20-30 minutes, and then passing into inert gas at 50-70 degrees C for 50 minutes. The solution is stirred under strong conditions followed by adding certain amount of ammonia at 50-70 degrees C for 30-50 minutes, washed with magnetic separation, and then vacuum dried to get iron (III) oxide composite. 40-60 mg prepared magnetic nanocomposite is dissolved in 10-15 ml pure water with stirring at 60-80 degrees C for 3-5 hours. The magnetic separation is carried out and dried in vacuum to prepare iron (III) oxide nanocomposite. The obtained magnetic nanocomposite is dispersed in pure water to obtain homogeneous magnetic nanocomposite suspension, and then 3-15 mu l drops are added and dried in vacuum at room temperature to obtain modified electrode magnetic nanocomposite. The potassium chloride, potassium ferricyanide and potassium ferrocyanide solution is provided as modified electrode for working electrode and saturated calomel electrode as reference electrode.