Adsorption of Rhodamine WT and Fluorscein Onto Quartz Between 25 and 83?C

Abstract

The adsorption of Rhodamine WT and Fluorescein onto quartz in water at pH 7 have been measured between 25?C and 85?C using flow-through experiments. The adsorption of both tracers onto quartz decreases with increasing temperature with Rhodamine WT adsorbing more than Fluorescein. At 50?C Fluorescein adsorption appears to decrease with increasing pH, consistent with the increasing negative charge on the quartz surface and increasing anionic character of dye. However the adsorption of Fluorescein appears to be independent of ionic strength at pH 5 which may be due to the small negative surface charge at pH values < 6.