Fluorescent Organofilms for Oxygen Sensing in Organic Solvents Using a Fiber Optic System

Oxygen quenching of the luminescence of the tris(2,2′-bipyridyl)ruthenium(II) complex [Ru(bpy)3]2+, entrapped in gelatin-containing microemulsion-based organogels, has been shown to be an accurate and precise method for measuring oxygen concentrations in organic solvents (such as toluene, hexane and isooctane). Film composition was investigated in order to obtain sensing phases with high sensitivity to oxygen and suitable response times. Using a fiber optic design combined with a continuous flow system configuration, the dynamic response of oxygen-sensing films was less than 1 min for a full signal change. A detection limit of 0.2 ppm of oxygen in hexane–5% chloroform was found.