Reagentless - Continuous Determination of Aqueous Ozone with Glass Tube Separator - Thin Film Semiconductor

Abstract

A method without any reagent for the determination of ultra-trace aqueous ozone utilizing a glass tube-separation process and a thin film semiconductor is proposed. The glass tube was used as the separator to transfer ozone from water into a gas phase. Ozone was transfered into clean air flowing in the tube and then was continuously monitored at the thin film semiconductor. Signals were proportional to concentration of aqueous ozone more than 5 ppb. Detection limit (S/N=3) was 0.02 ppt for aqueous ozone. The relative standard deviation (n=7) was 3.8 % at 7.6 ppb. The interference from hydrogen peroxide. monochloramine. and dichloramine were completely eliminated. The sensitivity of aqueous ozone was 45 times greater than that of hypochlorite.