ONLINE MONITORING OF TRACE AMOUNTS OF COPPER(II) IN STEAM CONDENSATE AND BOILER FEED-WATER BY FLOW-INJECTION ANALYSIS BASED ON ITS CATALYTIC EFFECT ON THE OXIDATION OF HYDROQUINONE BY HYDROGEN-PEROXIDE

A flow injection analysis (FIA) method for on-line monitoring of trace amounts of copper(II) in steam condensate and boiler feed-water is de scribed. This method is based on the catalytic effect of copper(II) on the oxidation of hydroquinone by hydrogen peroxide, the quinone produ ced being detected using UV-absorption at 490 nm. The effects of pH, t emperature, the concentrations of hydroquinone and hydrogen peroxide, and reaction time on the determination of the selectivity and the sens itivity of this method were investigated. An FIA-kinetic determination method with both high selectivity and sensitivity was obtained by the optimization of the detection conditions. Trace amounts of copper(II) in steam condensate and boiler feed-water in power stations were succ essfully analyzed on-line using this method.