Preparation of a Flow Single-drop Extraction System for Educational Use Capable of the Simultaneous and Continuous Observation of Extraction Behavior and Absorbance Change

A portable flow single-drop extraction system was prepared as an educational tool for facilitating the connection between actual extraction behavior and theory. In this system, an aqueous dye solution is circulated through a ring-shaped extraction cell equipped with a droplet introduction unit and a flow cell for absorbance detection. The dye is extracted into a droplet in the extraction cell. This system enables simultaneous and continuous observation of the image of the droplet in the extraction cell and changes in absorption spectrum or absorbance over time on the same screen by using a USB camera. It was suggested that the material balance in the extraction can be calculated from the decrease in absorbance of the circulating dye solution and the absorbance of the droplet after the extraction.