1-butyl-3-methylimidazole naphthoic formate ionic liquid and preparation method and application thereof

The invention discloses 1-butyl-3-methylimidazole naphthoic formate ionic liquid and a preparation method and application thereof. The structural formula of the 1-butyl-3-methylimidazole naphthoic formate ionic liquid is shown in the formula (I). The preparation method of the 1-butyl-3-methylimidazole naphthoic formate ionic liquid comprises the steps that 1, 1-naphthoic acid is added into an excessive amount of a sodium hydroxide solution to be subjected to a reaction to obtain reaction liquid A; 2, chloro1-butyl-3-methylimidazole is added into the reaction liquid A to be subjected to a reaction to obtain reaction liquid B; 3, water in the reaction liquid B is removed, then absolute ethyl alcohol is added, freezing crystallization and filtering are performed to remove NaCl in the system, and then ethyl alcohol is removed to obtain the 1-butyl-3-methylimidazole naphthoic formate ionic liquid. The 1-butyl-3-methylimidazole naphthoic formate ionic liquid has more conjugation structures compared with conventional ionic liquid, the fluorescent effect is better, and the sensitivity in fluorescence detection is greatly improved; the 1-butyl-3-methylimidazole naphthoic formate ionic liquid is hydrophobic ionic liquid, the stronger fluorescent sensitivity enhancing effect is achieved for weak fluorescent pollutant, and the higher application value is achieved on compound trace chromatography and fluorescence analysis.