Rhodamine dye, a xanthene dye, is often used as a tracer (Rhodamine WT) in water quality assessments. It’s had wide use as a ‘time of travel’ dye for both surface water and groundwater systems with the ability to stain organic materials. This has applications for the tracking of pollutants, assessing aeration and dispersion dynamics and looking at environments such as wetlands where processes are more complex.
Rhodamine is popular as it is highly stable in water, unlike other fluorescent dyes, and is suitable for use around humans, animals and plant life in low concentrations without adverse effects. Fluorometers allow the dye to be detected at very low concentrations with the amount of red light emitted directly proportional to the concentration of the dye.
