Quantification of the ozone dose delivered into a liquid by indirect plasma treatments: method and calibration of the Pittsburgh Green Fluorescence Probe

Determination of the ozone dose delivered into liquids by plasma systems is of importance in many emerging plasma applications, such as plasma medicine. Quantifcation of this dose remains extremely challenging due to the complex physico-chemical processes encountered in the gas plasma, the plasma–liquid interface and the liquid itself. Chemical probes have the potential to address the limitation of more traditional plasma diagnostic techniques but most commercial chemical probes are not specifc enough to be used in plasma applications. Here we report on the development of a method for the quantifcation of the ozone delivered into a liquid using Pittsburgh Green, a novel ozone-selective fuorescence probe. Entailed within this work is a method for the preparation of the probe solutions, the design of a calibration system and a normalized calibration curve correlating fuorescence intensity to actual ozone dose delivered to the liquid. This enables the quantitative comparison of ozone measurements performed with diferent spectrofuorometers and in different institutions.