FLOW-INJECTION DETERMINATION OF ORGANIC CONTAMINANTS IN WATER USING AN ULTRAVIOLET-MEDIATED TITANIUM-DIOXIDE FILM REACTOR

A novel reactor for use in the flow-injection determination of organic solutes in water was constructed by first immobilizing a thin film of titanium dioxide onto the inner surface of a length of Teflon tubing then wrapping the treated tubing around a near-UV illuminating source. The reactor was installed after the injector port of the flow system. Organic compounds injected in the flowing stream were oxidized photocatalytically to carbon dioxide, which was subsequently monitored by a conductivity detector. To optimize the sensitivity of detection, a number of reactor parameters, such as temperature, configuration and catalyst loading, were studied. The technique was applied to alcohols, formaldehyde, ethylene oxide and single-cell algae. The detection limit is 1 × 10-9 M methanol (in 20 μl). © 1990.