Period of Performance: 01/01/1995 - 12/31/1995


Phase 1 SBIR

Recipient Firm

Marktek (jointly With
939 S. Kirkwood Rd.
St. Louis, MO 63122
Principal Investigator


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.