Gas-liquid mass transfer characterization in a thin shrinking film at an atomization nozzle

•First local mass transfer analysis performed in a thin atomizing liquid film.•New method for local thickness and concentration measurements in atomizing liquid film.•The method relies on light absorption by an oxygen-sensitive dye, the resazurin.•Very high values of kL (2.2 × 10−3–1.2 × 10−2 m/s) have been measured.•kL of the liquid film decreases along the flow direction and from the core to the edges.