Detecting H_2S Gas Concentration by 1,8-Naphthalimides Fluorescent Probe

Aiming at the low sensitivity of traditional hydrogen sulfide detection method, a small-molecule fluorescent probe was designed and synthesized for hydrogen sulfide detection via introducing oxidizing group of nitro on the 1,8-naphthalimide fluorescence group, based on the nitro group could be reduced by hydrogen sulfide to produce the corresponding amino group. The fluorescence intensity of probe was very weak, and the fluorescence peaks were at λ=467 nm and λ=522 nm. After reacting with H₂S, fluorescent effect disappeared at 522 nm, it significantly enhanced at 467 nm. The fluorescence spectrum of fluorescent probe was measured after being introduced into H₂S, and the fluorescence intensity at 467 nm was analyzed. The experimental result showed an excellent linear relationship between H₂S gas concentration and fluorescence intensity, while the linear correlation coefficient was up to 0.979 3. Meanwhile, the minimum H₂S gas concentration that could be detected was only 0.88×10-6 mol·L-1. Fluorescence spectrometric detection of 1,8-naphthalimides solution can be used for the H₂S gas rapid determination in oil and gas fields.