Oxygen solubility measured in aqueous or oily media by a method using a non-invasive sensor
Résumé
The amount of dissolved oxygen (O2) in oils is one of the major factors that affect the extent of oil oxidation reactions. The aim of this work was to develop an experimental method to determine the Henry's law constant in oils, using a portable optical device for easy and non-intrusive O2 partial pressure measurement. The principle is based on the effect of quenching of luminescence by oxygen using a sensor probe glued inside a transparent glass flask. The method uses a mass conservation equation written for oxygen in both liquid and gaseous phases inside a closed flask. It was validated on water in the range of 5–50 °C, and then applied to non-polar media (dodecane, vegetable oil and Miglyol). The results show that oxygen is 5 times more soluble in sunflower oil than in water. This method is easy-to-implement and makes it possible to measure the Henry's constant for O2 in various types of vegetable oils.