A FLUOROMETRIC SENSOR FOR Cr(VI)

Hexavalent chromium, Cr(VI), in the usual form of oxo species, is used in manyindustrial processes and products. As a consequence, Cr(VI)= containingcompounds are often found in wastewater and contaminated sites. Since Cr(VI) isconsidered highly toxic and carcinogenic, it is extremely important to have areliable, easy-to-use, sensitive monitor for determining Cr(VI) concentrationsin process, on site, in real time.This proposal presents a description of the preliminary research necessary todevelop an easy-to-use, portable, sensitive, selective fiber-optic sensor forCr(VI). The envisioned sensor is based on the reportedly unique ability ofCr(VI) to quench the visible florescence of Rhodamine S, which is to beimmobilized in a matrix prepared by proven sol-gel techniques. One of the keyobjectives of the present research is to verify the rare selectivity of theRhodamine S system. Because silica sol-gel tends to dissolve in strong base,other oxide gel systems will be investigated as matrices to provide a sensorresistant to highly alkaline media as well.